Merge pull request #266 from hashrelay/flake

Add nix flake.

This allow to build the project executables with nix.

.github/workflows/build.yaml

@@ -1,34 +1,82 @@
 name: Continuous Integration Checks
 
-on: [push, pull_request]
+on: 
+  push:
+    branches:
+      - master
+  pull_request:
 
 jobs:
   build:
     strategy:
       fail-fast: false
       matrix:
-        platform: [ ubuntu-latest ]
+        platform: [ ubuntu-latest, macos-latest, windows-latest ]
         toolchain: [ stable ]
         include:
-          - toolchain: stable
-          - toolchain: stable
-            platform: macos-latest
-          - toolchain: stable
-            platform: windows-latest
+           - platform: windows-latest
+             arguments: --workspace --exclude watchtower-plugin
 
     runs-on: ${{ matrix.platform }}
     steps:
       - name: Checkout source code
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - name: Install Rust ${{ matrix.toolchain }} toolchain
-        uses: actions-rs/toolchain@v1
+        uses: dtolnay/rust-toolchain@master
         with:
           toolchain: ${{ matrix.toolchain }}
-          override: true
-          profile: minimal
+      - name: Install Protoc
+        uses: arduino/setup-protoc@v3
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
       - name: Build on Rust ${{ matrix.toolchain }}
         run: |
-          cargo build --verbose --color always
+          cargo build ${{ matrix.arguments }} --verbose --color always
       - name: Test on Rust ${{ matrix.toolchain }}
         run: |
-          cargo test --verbose --color always
+          cargo test ${{ matrix.arguments }} --verbose --color always
+
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout source code
+        uses: actions/checkout@v4
+      - name: Install Rust stable toolchain
+        uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: stable
+          components: rustfmt, clippy
+      - name: Install Protoc
+        uses: arduino/setup-protoc@v3
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+      - name: Run rustfmt
+        run: |
+          cargo fmt --verbose --check -- --color always
+      - name: Run clippy
+        run: |
+          cargo clippy --all-features --all-targets --color always -- --deny warnings
+          
+  python-lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout source code
+        uses: actions/checkout@v4
+      - name: Run black
+        uses: psf/black@stable
+        with:
+          src: "./watchtower-plugin/tests"
+          options: "--check -l 120"
+
+  check-flake:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+      - name: Check Nix flake inputs
+        uses: DeterminateSystems/flake-checker-action@v12
+      - name: Install Nix
+        uses: cachix/install-nix-action@v31
+      - name: Check flake
+        run: nix flake check
+

.github/workflows/cln-plugin.yaml

@@ -0,0 +1,96 @@
+name: CI tests for CLN watchtower-plugin
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+env:
+  bitcoind_version: "27.0"
+  cln_version: "24.11.1"
+
+jobs:
+  check-cln-cache:
+    runs-on: ubuntu-latest
+    outputs:
+      cache-hit: ${{ steps.cache.outputs.cache-hit }}
+    steps:
+      - name: Check CLN cache
+        id: cache
+        uses: actions/cache@v4
+        with:
+          path: lightning
+          key: ${{ runner.os }}-build-cache-cln-dev-v${{ env.cln_version }}
+
+  cache-cln:
+    runs-on: ubuntu-latest
+    needs: check-cln-cache
+    if: ${{ needs.check-cln-cache.outputs.cache-hit != 'true' }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.9'
+          check-latest: true
+      - uses: arduino/setup-protoc@v3
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+      - name: Create CLN cache
+        uses: actions/cache@v4
+        with:
+          path: lightning
+          key: ${{ runner.os }}-build-cache-cln-dev-v${{ env.cln_version }}
+      - name: Compile CLN
+        env:
+          PYTHON_KEYRING_BACKEND: keyring.backends.null.Keyring
+        run: |
+          sudo apt-get update && sudo apt-get install -y gettext
+          git clone https://github.com/ElementsProject/lightning.git && cd lightning && git checkout v${{ env.cln_version }}
+          pip install --user poetry && poetry install
+          ./configure && poetry run make -j 8
+
+  cln-plugin:
+    needs: cache-cln
+    if: ${{ always() }}
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.9'
+          check-latest: true
+      - uses: arduino/setup-protoc@v3
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: stable
+          components: rustfmt, clippy
+      - name: Install bitcoind
+        run: |
+          wget https://bitcoincore.org/bin/bitcoin-core-${{ env.bitcoind_version }}/bitcoin-${{ env.bitcoind_version }}-x86_64-linux-gnu.tar.gz
+          tar -xzf bitcoin-${{ env.bitcoind_version }}-x86_64-linux-gnu.tar.gz
+          ln -s $(pwd)/bitcoin-${{ env.bitcoind_version }}/bin/bitcoin* /usr/local/bin
+      - name: Load CLN cache
+        id: cache-cln
+        uses: actions/cache@v4
+        with:
+          path: lightning
+          key: ${{ runner.os }}-build-cache-cln-dev-v${{ env.cln_version }}
+      - name: Link CLN
+        run: |
+          cd lightning && sudo PATH=$PATH make install
+      - name: Install teos and the plugin
+        run: |
+          cargo install --locked --path teos
+          cargo install --locked --path watchtower-plugin
+      - name: Add test dependencies
+        run: |
+          cd watchtower-plugin/tests
+          pip install --user poetry && poetry install --no-root
+      - name: Run tests
+        run: |
+          cd watchtower-plugin/tests
+          VALGRIND=0 SLOW_MACHINE=1 poetry run pytest test.py --log-cli-level=INFO -s

.gitignore

@@ -1,4 +1,5 @@
 target
-*/target
-Cargo.lock
+__pycache__
 .vscode
+.idea
+result

CONTRIBUTING.md

@@ -9,7 +9,7 @@ We use `rustfmt` as our base code formatter. Before submitting a PR make sure yo
 cargo fmt
 ```
 
-In addition, we use [clippy](https://github.com/rust-lang/rust-clippy/) to detect catch common mistakes and improve the code:
+In addition, we use [clippy](https://github.com/rust-lang/rust-clippy/) to catch common mistakes and improve the code:
 
 ```bash
 cargo clippy
@@ -70,8 +70,37 @@ pub struct Responder {
 ```
 
 ## Test Coverage
-Tests should be provided to cover both positive and negative conditions. Test should cover both the proper execution as well as all the covered error paths. PR with no proper test coverage will be rejected. 
+Tests should be provided to cover both positive and negative conditions. Tests should cover both the proper execution as well as all the covered error paths. PR with no proper test coverage will not be merged.
 
-## Signing Commits
+## Git conventions 
 
-We require that all commits to be merge into master are signed. You can enable commit signing on GitHub by following [Signing commits](https://help.github.com/en/github/authenticating-to-github/signing-commits).
+### Commits, titles, and descriptions
+
+- Changes must be split logically in commits, such that a commit is self-contained
+- In general terms, all commits need to pass the test suite. There may be some exceptions to this rule if the change you are working on touches several components of the codebase and it makes more sense to split the change by component (or group of components)
+- Commit titles need to be short and explanatory. If we are, for instance, adding an RPC command to the backend, "Adds command X to the backend" will be a good short description, "Add command" or "Fix #123" where #123 is an issue referencing this feature **IS NOT**
+- Descriptions can be provided to give more context about what has been fixed and how
+
+### Pull requests
+
+- Pull request titles need to be explanatory, in the same way, commits titles were. If a PR includes a single commit, they can share the title, otherwise, a general title of what we are trying to achieve is required. **DO NOT REFERENCE ISSUES IN PULL REQUEST TITLES**, save that for the PR description
+- PR descriptions need to guide the reviewer into what has been changed. You can reference issues here. If the PR is a fix of a simple issue, "Fix #123" may suffice, however, if it involves several changes, a proper explanation of both what has been fixed and how is due. These are two good examples of PR descriptions, both long and short: [188](https://github.com/talaia-labs/rust-teos/pull/188), [194](https://github.com/talaia-labs/rust-teos/pull/194)
+- **WE DO NOT PILE "fix" COMMITS IN A PULL REQUEST**, that is, if some fixes are requested by reviewers, or something was missing from our original approach, it needs to be squashed. Do **NOT** do this:
+
+	```
+	886b0ff Adds X functionality to component Y
+	801ff5d Fixes the previous commit because Z
+	67ac345 Addresses review comments
+	7dc7fcd Updates X because G was missing
+	b60999c Adds missing test
+	...
+	```
+	
+- Create a new branch to work on your pull request. **DO NOT** work from the master branch of your fork*
+- **DO NOT** merge master into your branch, rebase master instead*
+
+	\* If you're not sure how to handle this, check external documentation on how to manage multiple remotes for the same repository.
+
+###  Signing Commits
+
+We require that all commits to be merged into master are signed. You can enable commit signing on GitHub by following [Signing commits](https://help.github.com/en/github/authenticating-to-github/signing-commits).

Cargo.toml

@@ -1,6 +1,8 @@
 [workspace]
+resolver = "2"
 
 members = [
     "teos",
     "teos-common",
-]
+    "watchtower-plugin"
+]

DEPENDENCIES.md

@@ -1,25 +1,24 @@
 # Dependencies
 
-`rusty-teos` has the following system-wide dependencies:
+`rust-teos` has the following system-wide dependencies:
 
 - `rust`
 - `bitcoind`
 
 ### Minimum Supported Rust Version (MSRV)
-FIXME: Define MSRV
+Refer to [toolchain](./rust-toolchain.toml)
 
 ### Installing Rust
 Refer to [rust-lang.org](https://www.rust-lang.org/tools/install).
 
 ### Installing bitcoind
 
-`rusty-teos` runs on top of a Bitcoin Core node. Other underlying Bitcoin nodes are not supported at the moment. 
+`rust-teos` runs on top of a Bitcoin Core node. Other underlying Bitcoin nodes are not supported at the moment. 
 
 You can get Bitcoin Core from [bitcoincore.org](https://bitcoincore.org/en/download/).
 
 Bitcoin needs to be running with the following options enabled:
 
-- `txindex` to be able to look for non-wallet transactions
 - `server` to run rpc commands
 
 Here's an example of a `bitcoin.conf` you can use for mainnet. **DO NOT USE THE PROVIDED RPC USER AND PASSWORD.**
@@ -31,9 +30,6 @@ rpcuser=user
 rpcpassword=passwd
 rpcservertimeout=600
 
-# [blockchain]
-txindex=1
-
 # [others]
 daemon=1
 debug=1

INSTALL.md

@@ -3,9 +3,9 @@
 The tower can be installed and tested using cargo:
 
 ```
-git https://github.com/sr-gi/rusty-teos.git
-cd rusty-teos
-cargo install --path teos
+git clone https://github.com/talaia-labs/rust-teos.git
+cd rust-teos
+cargo install --locked --path teos
 ```
 
 You can run tests with:
@@ -14,4 +14,8 @@ You can run tests with:
 cargo test
 ```
 
-Please refer to the cargo documentation for more detailed instructions.
+Please refer to the cargo documentation for more detailed instructions.
+
+# Systemd setup for backend
+
+Refer to [contrib](contrib/init/README.md) for a detailed explanation of how to set up your systemd service for `teosd`.

README.md

@@ -1,13 +1,16 @@
-**THIS IS CURRENTLY WIP**
-
 # The Eye of Satoshi (rust-teos)
 
 The Eye of Satoshi is a Lightning watchtower compliant with [BOLT13](https://github.com/sr-gi/bolt13), written in Rust.
 
-`rust-teos` consists in two main crates:
+[![discord](https://img.shields.io/discord/991334710611550208?logo=discord&style=plastic)](https://discord.gg/EyVbrNMDUP)
+[![build](https://img.shields.io/github/actions/workflow/status/talaia-labs/rust-teos/build.yaml?logo=github&style=plastic)](https://github.com/talaia-labs/rust-teos/actions/workflows/build.yaml)
+[![release](https://img.shields.io/github/v/release/talaia-labs/rust-teos?style=plastic)](https://github.com/talaia-labs/rust-teos/releases/latest)
 
-- `teos`: including the tower's main functionality (server-side) and a CLI.
-- `teos-common`: including shared functionality between server and client side (useful to build a client).
+
+`rust-teos` consists of two main crates:
+
+- `teos`: including the tower's main functionality (server-side) and a CLI. Compiling this crate will generate two binaries: `teosd` and `teos-cli`.
+- `teos-common`: including shared functionality between server and client-side (useful to build a client).
 
 ## Dependencies
 
@@ -18,8 +21,9 @@ Refer to [INSTALL.md](INSTALL.md)
 
 ## Running TEOS
 
-Make sure bitcoind is running before running `rust-teos` (it will fail at startup if it cannot connect to bitcoind). You can find
-[here](DEPENDENCIES.md#installing-bitcoind) a sample config file.
+Make sure `bitcoind` is running before running `teosd` (it will fail at startup if it cannot connect to `bitcoind`). [Here](DEPENDENCIES.md#installing-bitcoind) you can find a sample bitcoin.conf.
+
+Please see [Docker instructions](docker/README.md) for instructions on how to set up `teosd` in Docker.
 
 ### Starting the tower daemon ♖
 
@@ -31,31 +35,31 @@ teosd
 
 ### Configuration file and command line parameters
 
-`rust-teos` comes with a default configuration that can be found at [teos/src/config.rs](teos/src/config.rs). 
+`teosd` comes with a default configuration that can be found at [teos/src/config.rs](teos/src/config.rs). 
 
 The configuration includes, amongst others, where your data folder is placed, what network it connects to, etc.
 
 To change the configuration defaults you can:
 
-- Define a configuration file named `teos.toml` following the template (check [teos/src/conf_template.toml](teos/src/conf_template.toml)) and place it in the `data_dir` (that defaults to `~/.teos/`)
+- Define a configuration file named `teos.toml` following the template (check [conf_template.toml](teos/src/conf_template.toml)) and place it in the `data_dir` (that defaults to `~/.teos/`).
 
-and / or 
+and/or 
 
 - Add some global options when running the daemon (run `teosd -h` for more info).
 
-### Passing command line options to `teosd`
+### Passing command-line options to `teosd`
 
-Some configuration options can also be passed as options when running `teosd`. We can, for instance, change the tower data directory as follows:
+Some configuration options can also be specified when running `teosd`. We can, for instance, change the tower data directory as follows:
 
 ```
 teosd --datadir=<path_to_dir>
 ```
 
-### Running TEOS in another network
+### Running `teosd` in another network
 
-By default, `rust-teos` runs on `mainnet`. In order to run it on another network you need to change the network parameter in the configuration file or pass the network parameter as a command line option. Notice that if teos does not find a `bitcoind` node running in the same network that it is set to run, it will refuse to run.
+By default, `teosd` runs on `mainnet`. In order to run it on another network, you need to change the network parameter in the configuration file or pass the network parameter as a command-line option. Notice that if `teosd` does not find a `bitcoind` node running in the same network that it is set to run, it will refuse to run.
 
-The configuration file option to change the network where `teos` will run is `btc_network`:
+The configuration file option to change the network where `teosd` will run is `btc_network`:
 
 ```
 btc_network = mainnet
@@ -67,17 +71,38 @@ For regtest, it should look like:
 btc_network = regtest
 ```
 
+### Running `teosd` with Tor
+
+This requires a Tor daemon running on the same machine as `teosd` and a control port open on that daemon.
+
+Download Tor from the [torproject site](https://www.torproject.org/download/).
+
+To open Tor's control port, you add the following to the Tor config file ([source](https://2019.www.torproject.org/docs/faq.html.en#torrc)):
+
+```
+## The port on which Tor will listen for local connections from Tor
+## controller applications, as documented in control-spec.txt.
+ControlPort 9051
+
+## If you enable the controlport, be sure to enable one of these
+## authentication methods, to prevent attackers from accessing it.
+CookieAuthentication 1
+CookieAuthFileGroupReadable 1
+```
+
+Once the Tor daemon is running, and the control port is open, make sure to enable `--torsupport` when running `teosd`.
+
 ### Tower id and signing key
 
-`teos` needs a pair of keys that will serve as tower id and signing key. The former can be used by users to identify the tower, whereas the latter is used by the tower to sign responses. These keys are automatically generated on the first run, and can be refreshed by running `teos` with the `--overwritekey` flag. Notice that once a key is overwritten you won't be able to use the previous key again*.
+`teosd` needs a pair of keys that will serve as tower id and signing key. The former can be used by users to identify the tower, whereas the latter is used by the tower to sign responses. These keys are automatically generated on the first run and can be refreshed by running `teosd` with the `--overwritekey` flag. Notice that once a key is overwritten you won't be able to use the previous key again*.
 
-\* Old keys are actually kept in the tower's database as a fail safe in case you overwrite them by mistake. However, there is no automated way of switching back to and old key. Feel free to open an issue if you overwrote your key by mistake and need support to recover it.
+\* Old keys are actually kept in the tower's database as a fail-safe in case you overwrite them by mistake. However, there is no automated way of switching back to an old key. Feel free to open an issue if you overwrote your key by mistake and need support to recover it.
 
-## Interacting with a TEOS Instance
+## Interacting with a TEOS instance
 
-You can interact with a `teos` instance (either run by yourself or someone else) by using `teos-cli`. This is an admin tool that has privileged access to the watchtower, and it should therefore only be used within a trusted environment (for example, the same machine).
+You can interact with a `teosd` instance (either run by yourself or someone else) by using `teos-cli`. This is an admin tool that has privileged access to the watchtower, and it should therefore only be used within a trusted environment (for example, the same machine).
 
-While `teos-cli` works independently of `teos`, it shares the same configuration file by default, of which it only uses a subset of its settings. The folder can be changed using the `--datadir` command line argument, if desired.
+While `teos-cli` works independently of `teosd`, it shares the same configuration file by default, of which it only uses a subset of its settings. The folder can be changed using the `--datadir` command-line argument if desired.
 
 For help on the available arguments and commands, you can run:
 
@@ -85,9 +110,18 @@ For help on the available arguments and commands, you can run:
 teos-cli -h
 ```
 
-## Interacting with TEOS as a client
+### Running teos-cli remotely
 
-FIXME: Add client and docs
+To run `teos-cli` remotely, you'll need to take one extra step. When `teosd` is started up, self-signed certificates are automatically generated for a user to make a secure connection to the remote TEOS watchtower. When the CLI is run locally, it knows where to find these files. But if run remotely, these files need to be copied over to the machine where the CLI is being run.
+
+The files are generated to the data directory (by default stored at `~/.teos/`). To run remotely, users need to copy the `client.pem`, `client-key.pem`, and `ca.pem` files to the corresponding watchtower data directory on the machine where the CLI is being run. That is, by default, to `~/.teos/` on the remote machine.
+
+## Interacting with TEOS as a client
+### TEOS clients
+
+Here is a list of the available clients for `teos`:
+
+- [watchtower-client for CLN](watchtower-plugin/)
 
 ## Contributing 
 Refer to [CONTRIBUTING.md](CONTRIBUTING.md)

coffee.yml

@@ -0,0 +1,10 @@
+---
+plugin:
+  name: rust-teos
+  version: 0.2.0
+  lang: rust
+  install: |
+    cargo build --release --locked --package watchtower-plugin
+    cp target/release/watchtower-client .
+    cargo clean
+  main: watchtower-client

contrib/init/README.md

@@ -0,0 +1,42 @@
+**This document guides you into how to set-up a systemd service to run `teosd`.**
+
+Since the teos service requires bitcoin to run, it is strongly recommended to also create a [system service for bitcoin](https://github.com/bitcoin/bitcoin/blob/master/contrib/init/bitcoind.service).
+
+Once you have set the bitcoin service, proceed to copy [teosd.service](teosd.service) to the systemd folder, that is, if running from this folder:
+
+```
+cp teosd.service /etc/systemd/system
+```
+
+You can also create a file called `teosd.service` in the systemd folder and copy the content of [teosd.service](teosd.service) to it:
+
+```
+sudo vim /etc/systemd/system/teosd.service
+```
+
+Notice the provided service file is using `teos` both as user and group for the service, so you may want to update that if that is not the configuration you are intending to use. Here are the lines to be updated:
+
+```
+[Service]
+ExecStart=/home/<user>/.cargo/bin/teosd
+SyslogIdentifier=<user>
+
+# Directory creation and permissions
+####################################
+User=<user>
+Group=<group>
+```
+
+The next step is enabling the service. You can do so by running:
+
+```
+sudo systemctl enable teosd.service
+```
+
+Finally, you can start the service by running:
+
+```
+sudo systemctl start teosd.service
+```
+
+From that point on, the tower will be run every time your system is turned on, and restarted if needed.

contrib/init/teosd.service

@@ -0,0 +1,46 @@
+[Unit]
+Description=The Eye of Satoshi daemon
+Requires=bitcoind.service
+After=bitcoind.service 
+Wants=network-online.target
+After=network-online.target
+
+[Service]
+ExecStart=/home/teos/.cargo/bin/teosd
+StandardOutput=journal
+StandardError=journal
+SyslogIdentifier=teos
+
+# Process management
+####################
+Type=simple
+Restart=on-failure
+TimeoutSec=300
+RestartSec=60
+
+# Directory creation and permissions
+####################################
+User=teos
+Group=teos
+
+# Hardening measures
+####################
+# Provide a private /tmp and /var/tmp.
+PrivateTmp=true
+
+# Mount /usr, /boot/ and /etc read-only for the process.
+ProtectSystem=full
+
+# Disallow the process and all of its children to gain
+# new privileges through execve().
+NoNewPrivileges=true
+
+# Use a new /dev namespace only populated with API pseudo devices
+# such as /dev/null, /dev/zero and /dev/random.
+PrivateDevices=true
+
+# Deny the creation of writable and executable memory mappings.
+MemoryDenyWriteExecute=true
+
+[Install]
+WantedBy=multi-user.target

docker/Dockerfile

@@ -0,0 +1,49 @@
+# Use the rust image as the base image for the build stage
+FROM rust:latest AS builder
+
+# Copy the rust-teos source code
+COPY . /tmp/rust-teos
+
+# Install the dependencies required for building rust-teos
+RUN apt-get update\
+    && apt-get -y --no-install-recommends install libffi-dev libssl-dev musl-tools pkg-config
+
+RUN cd /tmp/rust-teos \
+    && rustup target add x86_64-unknown-linux-musl \
+    # Rustfmt is needed to format the grpc stubs generated by tonic
+    && rustup component add rustfmt \
+    # Cross compile with musl as the target, so teosd can run on alpine
+    && RUSTFLAGS='-C target-feature=+crt-static' cargo build --manifest-path=teos/Cargo.toml --locked --release --target x86_64-unknown-linux-musl
+
+# Use a new stage with a smaller base image to reduce image size
+FROM alpine:latest
+
+RUN apk update && apk upgrade
+
+# UID and GID for the teosd user
+ENV TEOS_UID=1001 TEOS_GID=1001
+
+# Copy the teos binaries from the build stage to the new stage
+COPY --from=builder \
+    /tmp/rust-teos/target/x86_64-unknown-linux-musl/release/teosd \
+    /tmp/rust-teos/target/x86_64-unknown-linux-musl/release/teos-cli /usr/local/bin/
+
+# Copy the entrypoint script to the container
+COPY docker/entrypoint.sh /entrypoint.sh
+
+# Set the entrypoint script as executable and add running user
+RUN chmod +x /entrypoint.sh \
+    && addgroup -g ${TEOS_GID} -S teos \
+    && adduser -S -G teos -u ${TEOS_UID} teos
+
+# Expose the default port used by teosd
+EXPOSE 9814/tcp
+
+# Switch user so that we don't run stuff as root
+USER teos
+
+# Create the teos data directory
+RUN mkdir /home/teos/.teos
+
+# Start teosd when the container starts
+ENTRYPOINT [ "/entrypoint.sh" ]

docker/README.md

@@ -0,0 +1,113 @@
+## Running `teosd` in a docker container
+A `teos` image can be built from the Dockerfile located in `docker`. You can create the image by running:
+
+	cd rust-teos
+	docker build -f docker/Dockerfile -t teos .
+	
+Then we can create a container by running:
+
+	docker run -it teos
+
+One way to feed `teos` custom config options is to set environment variables:
+
+	docker run -it -e <ENV_VARIABLES> teos
+	
+Notice that the ENV variables are optional, if unset the corresponding default setting is used. The following ENVs are available:
+
+```
+- API_BIND=<teos_api_hostname>
+- API_PORT=<teos_api_port>
+- RPC_BIND=<teos_rpc_hostname>
+- RPC_PORT=<teos_rpc_port>
+- BTC_NETWORK=<btc_network>
+- BTC_RPC_CONNECT=<btc_node_hostname>
+- BTC_RPC_PORT=<btc_node_port>
+- BTC_RPC_USER=<btc_rpc_username>
+- BTC_RPC_PASSWORD=<btc_rpc_password>
+# The following options can be set turned on by setting them to "true"
+- DEBUG=<debug_bool>
+- DEPS_DEBUG=<deps_debug_bool>
+- OVERWRITE_KEY=<overwrite_key_bool>
+- FORCE_UPDATE=<force_update_bool>
+```
+
+### Volume persistence
+
+You may also want to run docker with a volume, so you can have data persistence in `teosd` databases and keys.
+If so, run:
+
+    docker volume create teos-data
+    
+And add the the mount parameter to `docker run`:
+
+    -v teos-data:/home/teos/.teos
+
+If you are running `teosd` and `bitcoind` in the same machine, continue reading for how to create the container based on your OS.
+
+### `bitcoind` running on the same machine (UNIX)
+The easiest way to run both together in the same machine using UNIX is to set the container to use the host network.
+	
+For example, if both `teosd` and `bitcoind` are running on default settings, run:
+    
+```
+docker run \
+  --network=host \
+  --name teos \
+  -v teos-data:/home/teos/.teos \
+  -e BTC_RPC_USER=<btc_rpc_username> \
+  -e BTC_RPC_PASSWORD=<btc_rpc_password> \
+  -it teos
+```
+
+Notice that you may still need to set your RPC authentication details, since, hopefully, your credentials won't match the `teosd` defaults.
+
+### `bitcoind` running on the same machine (OSX or Windows)
+
+Docker for OSX and Windows does not allow to use the host network (nor to use the `docker0` bridge interface). To work around this
+you can use the special `host.docker.internal` domain:
+
+```
+docker run \
+  -p 9814:9814 \
+  -p 8814:8814 \
+  --name teos \
+  -v teos-data:/home/teos/.teos \
+  -e BTC_RPC_CONNECT=host.docker.internal \
+  -e BTC_RPC_USER=<btc_rpc_username> \
+  -e BTC_RPC_PASSWORD=<btc_rpc_password> \
+  -e API_BIND=0.0.0.0 \
+  -e RPC_BIND=0.0.0.0 \
+  -it teos
+```
+
+Notice that we also needed to add `API_BIND=0.0.0.0` and `RPC_BIND=0.0.0.0` to bind the API to all interfaces of the container.
+Otherwise it will bind to `localhost` and we won't be able to send requests to the tower from the host.
+
+### Interacting with a TEOS instance
+
+Once our `teos` instance is running in the container, we can interact with it using `teos-cli`. We have two main ways of doing so:
+
+1) You can open a shell to the Docker instance by calling:
+
+`docker exec -it <CONTAINER_NAME> sh`
+
+Then you can use the `teos-cli` binary from inside the container as you would use it from your host machine.
+
+2) Using `teos-cli` remotely (assuming you have it installed in the source machine) and pointing to the container. To do so, you will need to copy over the necessary credentials to the host machine. To do so, you can follow the instructions in [the main README](https://github.com/talaia-labs/rust-teos/blob/master/README.md#running-teos-cli-remotely).
+
+### Plugging in Tor
+
+You may have noticed, in the above section where the environment variables are covered, that the Tor options are nowhere to be found. That's because these instructions assume that users will likely be setting up Tor in another container.
+
+On the machine where you have Tor running, you can follow [these instructions](https://community.torproject.org/onion-services/setup/) for setting up a hidden service manually.
+
+For instance, if you're running `teosd` in a Docker container on the same machine as where Tor is running, you can create a hidden service from the host machine to hide the IP of the `teosd` API (listening on port 9814 for example). If you're using Linux, you can do so by editing your `torrc` file on the host machine with the below option:
+
+```
+HiddenServiceDir /var/lib/tor/teosd # Path for Linux. This may differ depending on your OS.
+HiddenServicePort 9814 127.0.0.1:9814
+```
+
+Then restart Tor.
+
+If all works correctly, the hidden service public key will be located in the `HiddenServiceDir` you set above, in the file called `hostname`.

docker/entrypoint.sh

@@ -0,0 +1,66 @@
+#!/bin/sh
+
+# Define the start command
+START_COMMAND="teosd"
+
+# Set the API bind address
+if [[ ! -z ${API_BIND} ]]; then
+    START_COMMAND="$START_COMMAND --apibind $API_BIND"
+fi
+
+# Set the API port
+if [[ ! -z ${API_PORT} ]]; then
+    START_COMMAND="$START_COMMAND --apiport $API_PORT"
+fi
+
+# Set the RPC bind address
+if [[ ! -z ${RPC_BIND} ]]; then
+    START_COMMAND="$START_COMMAND --rpcbind $RPC_BIND"
+fi
+
+# Set the RPC port
+if [[ ! -z ${RPC_PORT} ]]; then
+    START_COMMAND="$START_COMMAND --rpcport $RPC_PORT"
+fi
+
+# Set the Bitcoin network
+if [[ ! -z ${BTC_NETWORK} ]]; then
+    START_COMMAND="$START_COMMAND --btcnetwork $BTC_NETWORK"
+fi
+
+# Set the Bitcoin RPC credentials
+if [[ ! -z ${BTC_RPC_USER} ]]; then
+    START_COMMAND="$START_COMMAND --btcrpcuser $BTC_RPC_USER"
+fi
+
+if [[ ! -z ${BTC_RPC_PASSWORD} ]]; then
+    START_COMMAND="$START_COMMAND --btcrpcpassword $BTC_RPC_PASSWORD"
+fi
+
+# Set the Bitcoin RPC connection details
+if [[ ! -z ${BTC_RPC_CONNECT} ]]; then
+    START_COMMAND="$START_COMMAND --btcrpcconnect $BTC_RPC_CONNECT"
+fi
+
+if [[ ! -z ${BTC_RPC_PORT} ]]; then
+    START_COMMAND="$START_COMMAND --btcrpcport $BTC_RPC_PORT"
+fi
+
+if [ "${DEBUG}" == "true" ]; then
+    START_COMMAND="$START_COMMAND --debug"
+fi
+
+if [ "${DEPS_DEBUG}" == "true" ]; then
+    START_COMMAND="$START_COMMAND --depsdebug"
+fi
+
+if [ "${OVERWRITE_KEY}" == "true" ]; then
+    START_COMMAND="$START_COMMAND --overwritekey"
+fi
+
+if [ "${FORCE_UPDATE}" == "true" ]; then
+    START_COMMAND="$START_COMMAND --forceupdate"
+fi
+
+# Start the TEOS daemon
+$START_COMMAND

flake.lock

@@ -0,0 +1,116 @@
+{
+  "nodes": {
+    "crane": {
+      "locked": {
+        "lastModified": 1758758545,
+        "narHash": "sha256-NU5WaEdfwF6i8faJ2Yh+jcK9vVFrofLcwlD/mP65JrI=",
+        "owner": "ipetkov",
+        "repo": "crane",
+        "rev": "95d528a5f54eaba0d12102249ce42f4d01f4e364",
+        "type": "github"
+      },
+      "original": {
+        "owner": "ipetkov",
+        "repo": "crane",
+        "type": "github"
+      }
+    },
+    "fenix": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ],
+        "rust-analyzer-src": "rust-analyzer-src"
+      },
+      "locked": {
+        "lastModified": 1758782550,
+        "narHash": "sha256-olCvyP5r6+HQTl2EUudtjlA5UammsBpkzAl0l9+utZc=",
+        "owner": "nix-community",
+        "repo": "fenix",
+        "rev": "32f4e350c03cc5762be811e9c700e8696cd13c02",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "fenix",
+        "type": "github"
+      }
+    },
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1731533236,
+        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1758589230,
+        "narHash": "sha256-zMTCFGe8aVGTEr2RqUi/QzC1nOIQ0N1HRsbqB4f646k=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "d1d883129b193f0b495d75c148c2c3a7d95789a0",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-25.05",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "crane": "crane",
+        "fenix": "fenix",
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    },
+    "rust-analyzer-src": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1758620797,
+        "narHash": "sha256-Ly4rHgrixFMBnkbMursVt74mxnntnE6yVdF5QellJ+A=",
+        "owner": "rust-lang",
+        "repo": "rust-analyzer",
+        "rev": "905641f3520230ad6ef421bcf5da9c6b49f2479b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "rust-lang",
+        "ref": "nightly",
+        "repo": "rust-analyzer",
+        "type": "github"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,114 @@
+{
+  description = "Build teos (The Eye of Satoshi) server and plugin";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
+
+    crane.url = "github:ipetkov/crane";
+
+    fenix = {
+      url = "github:nix-community/fenix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs =
+    {
+      nixpkgs,
+      crane,
+      fenix,
+      flake-utils,
+      ...
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+
+        inherit (pkgs) lib;
+
+        craneLib = (crane.mkLib pkgs).overrideToolchain fenix.packages.${system}.stable.minimalToolchain;
+
+        env = {
+          PROTOC = "${pkgs.protobuf}/bin/protoc";
+          PKG_CONFIG_PATH = "${pkgs.openssl.dev}/lib/pkgconfig";
+          LD_LIBRARY_PATH = lib.makeLibraryPath [ pkgs.openssl.out ];
+        };
+        commonArgs = {
+          inherit env;
+          strictDeps = true;
+
+          nativeBuildInputs = [
+            pkgs.pkg-config
+            pkgs.rustfmt # needed for tonic build
+            pkgs.cacert
+            pkgs.openssl.dev
+          ];
+
+          buildInputs =
+            [ ]
+            ++ lib.optionals pkgs.stdenv.isDarwin [
+              # Additional darwin specific inputs can be set here
+              pkgs.libiconv
+            ];
+        };
+
+        fileSetForCrate =
+          crate:
+          lib.fileset.toSource {
+            root = ./.;
+            fileset = lib.fileset.unions [
+              ./Cargo.toml
+              ./Cargo.lock
+              ./teos-common
+              ./teos
+              ./watchtower-plugin
+              crate
+            ];
+          };
+
+        plugin = craneLib.buildPackage (
+          commonArgs
+          // {
+            pname = "watchtower-plugin";
+            cargoExtraArgs = "-p watchtower-plugin";
+            src = fileSetForCrate ./watchtower-plugin;
+            inherit (craneLib.crateNameFromCargoToml { cargoToml = ./watchtower-plugin/Cargo.toml; }) version;
+          }
+        );
+        teos = craneLib.buildPackage (
+          commonArgs
+          // {
+            pname = "teos";
+            cargoExtraArgs = "-p teos";
+            src = fileSetForCrate ./teos;
+            inherit (craneLib.crateNameFromCargoToml { cargoToml = ./teos/Cargo.toml; }) version;
+          }
+        );
+      in
+      {
+        packages = {
+          inherit plugin teos;
+          default = teos;
+        };
+
+        apps = {
+          plugin = flake-utils.lib.mkApp { drv = plugin; };
+          teos = flake-utils.lib.mkApp { drv = teos; };
+        };
+
+        formatter = pkgs.nixfmt-tree;
+
+        checks = {
+          inherit teos plugin;
+        };
+
+        devShells.default = craneLib.devShell {
+          inherit env;
+          packages = commonArgs.buildInputs ++ commonArgs.nativeBuildInputs;
+        };
+      }
+    );
+}

rust-toolchain.toml

@@ -0,0 +1,6 @@
+[toolchain]
+channel = "1.81.0"
+components = [
+    "rustfmt",
+    "clippy",
+]

teos-common/Cargo.toml

@@ -1,19 +1,27 @@
 [package]
 name = "teos-common"
-version = "0.0.1"
+version = "0.2.0"
 authors = ["Sergi Delgado Segura <sergi.delgado.s@gmail.com>"]
-edition = "2018"
+edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
 # General
-hex = "0.4.3"
+hex = { version = "0.4.3", features = [ "serde" ] }
+prost = "0.12"
+rusqlite = { version = "0.26.0", features = [ "bundled", "limits" ] }
+serde = "1.0.130"
+serde_json = "1.0"
+tonic = "0.11"
 
 # Crypto
 rand = "0.8.4"
 chacha20poly1305 = "0.8.0"
 
 # Bitcoin and Lightning
-bitcoin = "0.27"
-lightning = "0.0.99"
+bitcoin = { version = "0.32.0", features = [ "serde" ] }
+lightning = "0.1.0"
+
+[build-dependencies]
+tonic-build = "0.11"

teos-common/build.rs

@@ -0,0 +1,30 @@
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    tonic_build::configure()
+        .type_attribute(".", "#[derive(serde::Serialize, serde::Deserialize)]")
+        .type_attribute("AppointmentData.appointment_data", "#[serde(untagged)]")
+        .field_attribute("AppointmentData.appointment_data", "#[serde(flatten)]")
+        .field_attribute("appointment_data", "#[serde(rename = \"appointment\")]")
+        .field_attribute("user_id", "#[serde(with = \"hex::serde\")]")
+        .field_attribute("locator", "#[serde(with = \"hex::serde\")]")
+        .field_attribute(
+            "locators",
+            "#[serde(with = \"crate::ser::serde_vec_bytes\")]",
+        )
+        .field_attribute("encrypted_blob", "#[serde(with = \"hex::serde\")]")
+        .field_attribute("dispute_txid", "#[serde(with = \"crate::ser::serde_be\")]")
+        .field_attribute("penalty_txid", "#[serde(with = \"crate::ser::serde_be\")]")
+        .field_attribute("penalty_rawtx", "#[serde(with = \"hex::serde\")]")
+        .field_attribute(
+            "GetAppointmentResponse.status",
+            "#[serde(with = \"crate::ser::serde_status\")]",
+        )
+        .compile(
+            &[
+                "proto/common/teos/v2/appointment.proto",
+                "proto/common/teos/v2/user.proto",
+            ],
+            &["proto/common/teos/v2"],
+        )?;
+
+    Ok(())
+}

teos-common/proto/common/teos/v2/appointment.proto

@@ -0,0 +1,75 @@
+syntax = "proto3";
+package common.teos.v2;
+
+message Appointment {
+    /*
+    Contains the basic information about an appointment (Watcher) and it's used for messages like
+    AddAppointmentRequest or encapsulated inside AppointmentData for GetAppointmentResponse
+    */
+  
+    bytes locator = 1;
+    bytes encrypted_blob = 2;
+    uint32 to_self_delay = 3;
+  
+  }
+  
+  message Tracker {
+    // It's the equivalent of an appointment message from data held by the Responder.
+  
+    bytes dispute_txid = 1;
+    bytes penalty_txid = 2;
+    bytes penalty_rawtx = 3;
+  }
+  
+  message AppointmentData {
+    /*
+    Encapsulates the data for a GetAppointmentResponse, given it can be an appointment (data is on the Watcher) or a
+    tracker (data is on the Responder).
+    */
+  
+    oneof appointment_data {
+      Appointment appointment = 1;
+      Tracker tracker = 2;
+    }
+  }
+  
+  message AddAppointmentRequest {
+    // Request to add an appointment to the backend, contains the appointment data and the user signature.
+  
+    Appointment appointment = 1;
+    string signature = 2;
+  }
+  
+  message AddAppointmentResponse {
+    /*
+    Response to an AddAppointmentRequest, contains the locator to identify the added appointment, the tower signature,
+    the block at which the tower has started (or will start) watching for the appointment, and the updated subscription
+    information.
+     */
+  
+    bytes locator = 1;
+    uint32 start_block = 2;
+    string signature = 3;
+    uint32 available_slots = 4;
+    uint32 subscription_expiry = 5;
+  }
+  
+  message GetAppointmentRequest {
+    // Request to get information about an appointment. Contains the appointment locator and a signature by the user.
+  
+    bytes locator = 1;
+    string signature = 2;
+  }
+  
+  message GetAppointmentResponse {
+    // Response to a GetAppointmentRequest. Contains the appointment data encapsulated in an AppointmentData message.
+  
+    AppointmentData appointment_data = 1;
+    enum AppointmentStatus {
+      NOT_FOUND = 0;
+      BEING_WATCHED = 1;
+      DISPUTE_RESPONDED = 2;
+  
+    }
+    AppointmentStatus status = 2;
+  }

teos-common/proto/common/teos/v2/user.proto

@@ -0,0 +1,32 @@
+syntax = "proto3";
+package common.teos.v2;
+
+message RegisterRequest {
+    // Requests a user registration with the tower. Contains the user id in the form of a compressed ECDSA public key.
+  
+    bytes user_id = 1;
+  }
+  
+  message RegisterResponse {
+    // Response to a RegisterRequest, contains the registration information alongside the tower signature of the agreement.
+  
+    bytes user_id = 1;
+    uint32 available_slots = 2;
+    uint32 subscription_start = 3;
+    uint32 subscription_expiry = 4;
+    string subscription_signature = 5;
+  }
+
+  message GetSubscriptionInfoRequest {
+    // Request to get a specific user's subscription info.
+
+    string signature = 1;
+}
+
+message GetSubscriptionInfoResponse {
+  // Response with the information the tower has about a specific user
+
+  uint32 available_slots = 1;
+  uint32 subscription_expiry = 2;
+  repeated bytes locators = 3;
+}

teos-common/src/appointment.rs

@@ -1,15 +1,17 @@
 //! Logic related to appointments shared between users and the towers.
 
-use hex;
+use serde::{Deserialize, Serialize};
 use std::array::TryFromSliceError;
 use std::{convert::TryInto, fmt};
 
 use bitcoin::Txid;
 
+use crate::protos as msgs;
+
 pub const LOCATOR_LEN: usize = 16;
 
 /// User identifier for appointments.
-#[derive(Debug, Eq, PartialEq, Copy, Clone, Hash)]
+#[derive(Debug, Eq, PartialEq, Copy, Clone, Hash, Serialize, Deserialize)]
 pub struct Locator([u8; LOCATOR_LEN]);
 
 impl Locator {
@@ -19,36 +21,42 @@ impl Locator {
     }
 
     /// Encodes a locator into its byte representation.
-    pub fn serialize(&self) -> Vec<u8> {
+    pub fn to_vec(&self) -> Vec<u8> {
         self.0.to_vec()
     }
 
     /// Builds a locator from its byte representation.
-    pub fn deserialize(data: &[u8]) -> Result<Self, TryFromSliceError> {
+    pub fn from_slice(data: &[u8]) -> Result<Self, TryFromSliceError> {
         data.try_into().map(Self)
     }
 }
 
-impl std::str::FromStr for Locator {
-    type Err = String;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let raw_locator = hex::decode(s).map_err(|_| "Locator is not hex encoded")?;
-        Locator::deserialize(&raw_locator)
-            .map_err(|_| "Locator cannot be built from the given data".into())
-    }
-}
-
 impl fmt::Display for Locator {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}", hex::encode(self.serialize()))
+        write!(f, "{}", hex::encode(self.to_vec()))
+    }
+}
+
+impl AsRef<[u8]> for Locator {
+    fn as_ref(&self) -> &[u8] {
+        &self.0
+    }
+}
+
+impl hex::FromHex for Locator {
+    type Error = String;
+
+    fn from_hex<T: AsRef<[u8]>>(hex: T) -> Result<Self, Self::Error> {
+        let raw_locator = hex::decode(hex).map_err(|_| "Locator is not hex encoded")?;
+        Locator::from_slice(&raw_locator)
+            .map_err(|_| "Locator cannot be built from the given data".into())
     }
 }
 
 /// Contains data regarding an appointment between a client and the tower.
 ///
 /// An appointment is requested for every new channel update.
-#[derive(Debug, Eq, PartialEq, Clone)]
+#[derive(Debug, Eq, PartialEq, Clone, Serialize, Deserialize)]
 pub struct Appointment {
     /// The user identifier for the appointment.
     pub locator: Locator,
@@ -62,6 +70,7 @@ pub struct Appointment {
 }
 
 /// Represents all the possible states of an appointment in the tower, or in a response to a client request.
+#[derive(Serialize, Deserialize, Debug)]
 pub enum AppointmentStatus {
     NotFound = 0,
     BeingWatched = 1,
@@ -86,7 +95,7 @@ impl std::str::FromStr for AppointmentStatus {
             "being_watched" => Ok(AppointmentStatus::BeingWatched),
             "dispute_responded" => Ok(AppointmentStatus::DisputeResponded),
             "not_found" => Ok(AppointmentStatus::NotFound),
-            _ => Err(format!("Unknown status: {}", s)),
+            _ => Err(format!("Unknown status: {s}")),
         }
     }
 }
@@ -98,7 +107,7 @@ impl fmt::Display for AppointmentStatus {
             AppointmentStatus::DisputeResponded => "dispute_responded",
             AppointmentStatus::NotFound => "not_found",
         };
-        write!(f, "{}", s)
+        write!(f, "{s}")
     }
 }
 
@@ -118,10 +127,27 @@ impl Appointment {
     /// `locator || encrypted_blob || to_self_delay`
     ///
     /// All values are big endian.
-    pub fn serialize(&self) -> Vec<u8> {
-        let mut result = self.locator.serialize();
+    pub fn to_vec(&self) -> Vec<u8> {
+        let mut result = self.locator.to_vec();
         result.extend(&self.encrypted_blob);
         result.extend(self.to_self_delay.to_be_bytes().to_vec());
         result
     }
 }
+
+impl From<Appointment> for msgs::Appointment {
+    fn from(a: Appointment) -> Self {
+        Self {
+            locator: a.locator.to_vec(),
+            encrypted_blob: a.encrypted_blob.clone(),
+            to_self_delay: a.to_self_delay,
+        }
+    }
+}
+
+/// Computes the number of slots an appointment takes from a user subscription.
+///
+/// This is based on the [encrypted_blob](Appointment::encrypted_blob) size and the slot size that was defined by the [Gatekeeper](crate::gatekeeper::Gatekeeper).
+pub fn compute_appointment_slots(blob_size: usize, blob_max_size: usize) -> u32 {
+    (blob_size as f32 / blob_max_size as f32).ceil() as u32
+}

teos-common/src/cryptography.rs

@@ -1,14 +1,13 @@
 //! Cryptography module, used in the interaction between users and towers.
 
-use rand::distributions::Uniform;
-use rand::Rng;
-
 use chacha20poly1305::aead::{Aead, NewAead};
 use chacha20poly1305::{ChaCha20Poly1305, Key, Nonce};
+use rand::distributions::Uniform;
+use rand::Rng;
 
+use bitcoin::consensus;
 use bitcoin::hashes::{sha256, Hash};
 use bitcoin::secp256k1::{Error, PublicKey, Secp256k1, SecretKey};
-use bitcoin::util::psbt::serialize::{Deserialize, Serialize};
 use bitcoin::{Transaction, Txid};
 use lightning::util::message_signing;
 
@@ -20,7 +19,7 @@ pub enum DecryptingError {
 }
 
 /// Shadows [message_signing::sign].
-pub fn sign(msg: &[u8], sk: &SecretKey) -> Result<String, Error> {
+pub fn sign(msg: &[u8], sk: &SecretKey) -> String {
     message_signing::sign(msg, sk)
 }
 
@@ -47,11 +46,11 @@ pub fn encrypt(
 ) -> Result<Vec<u8>, chacha20poly1305::aead::Error> {
     // Defaults is [0; 12]
     let nonce = Nonce::default();
-    let _k = sha256::Hash::hash(secret);
-    let key = Key::from_slice(&_k);
+    let k = sha256::Hash::hash(secret.as_byte_array());
+    let key = Key::from_slice(k.as_byte_array());
 
     let cypher = ChaCha20Poly1305::new(key);
-    cypher.encrypt(&nonce, message.serialize().as_ref())
+    cypher.encrypt(&nonce, consensus::serialize(message).as_ref())
 }
 
 /// Decrypts an encrypted blob of data using `chacha20poly1305` and a given secret.
@@ -64,13 +63,13 @@ pub fn encrypt(
 pub fn decrypt(encrypted_blob: &[u8], secret: &Txid) -> Result<Transaction, DecryptingError> {
     // Defaults is [0; 12]
     let nonce = Nonce::default();
-    let _k = sha256::Hash::hash(secret);
-    let key = Key::from_slice(&_k);
+    let k = sha256::Hash::hash(secret.as_byte_array());
+    let key = Key::from_slice(k.as_byte_array());
 
     let cypher = ChaCha20Poly1305::new(key);
 
     match cypher.decrypt(&nonce, encrypted_blob.as_ref()) {
-        Ok(tx_bytes) => Transaction::deserialize(&tx_bytes).map_err(DecryptingError::Encode),
+        Ok(tx_bytes) => consensus::deserialize(&tx_bytes).map_err(DecryptingError::Encode),
         Err(e) => Err(DecryptingError::AED(e)),
     }
 }
@@ -81,17 +80,13 @@ pub fn decrypt(encrypted_blob: &[u8], secret: &Txid) -> Result<Transaction, Decr
 pub fn get_random_bytes(size: usize) -> Vec<u8> {
     let mut rng = rand::thread_rng();
     let uniform_u8 = Uniform::new(u8::MIN, u8::MAX);
-    let v: Vec<u8> = (&mut rng).sample_iter(uniform_u8).take(size).collect();
-
-    v
+    (&mut rng).sample_iter(uniform_u8).take(size).collect()
 }
 
 /// Gets a key pair generated in a pseudorandom way.
 pub fn get_random_keypair() -> (SecretKey, PublicKey) {
-    let raw_sk = get_random_bytes(32);
-
     loop {
-        if let Ok(sk) = SecretKey::from_slice(&raw_sk) {
+        if let Ok(sk) = SecretKey::from_slice(&get_random_bytes(32)) {
             return (sk, PublicKey::from_secret_key(&Secp256k1::new(), &sk));
         }
     }
@@ -99,8 +94,11 @@ pub fn get_random_keypair() -> (SecretKey, PublicKey) {
 
 #[cfg(test)]
 mod tests {
+    use std::str::FromStr;
+
     use super::*;
-    use bitcoin::{hashes::hex::FromHex, util::psbt::serialize::Deserialize};
+    use bitcoin::consensus;
+    use bitcoin::hashes::hex::FromHex;
 
     const HEX_TX: &str = "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";
     const HEX_TXID: &str = "d6ac4a5e61657c4c604dcde855a1db74ec6b3e54f32695d72c5e11c7761ea1b4";
@@ -111,17 +109,17 @@ mod tests {
         let expected_enc_blob = Vec::from_hex(ENC_BLOB).unwrap();
         let tx_bytes = Vec::from_hex(HEX_TX).unwrap();
 
-        let tx = Transaction::deserialize(&tx_bytes).unwrap();
-        let txid = Txid::from_hex(HEX_TXID).unwrap();
+        let tx: Transaction = consensus::deserialize(&tx_bytes).unwrap();
+        let txid = bitcoin::Txid::from_str(HEX_TXID).unwrap();
         assert_eq!(encrypt(&tx, &txid).unwrap(), expected_enc_blob);
     }
 
     #[test]
     fn test_decrypt() {
-        let expected_tx = Transaction::deserialize(&Vec::from_hex(HEX_TX).unwrap()).unwrap();
+        let expected_tx = consensus::deserialize(&Vec::from_hex(HEX_TX).unwrap()).unwrap();
 
         let encrypted_blob = Vec::from_hex(ENC_BLOB).unwrap();
-        let txid = Txid::from_hex(HEX_TXID).unwrap();
+        let txid = bitcoin::Txid::from_str(HEX_TXID).unwrap();
         assert_eq!(decrypt(&encrypted_blob, &txid).unwrap(), expected_tx);
     }
 }

teos-common/src/dbm.rs

@@ -0,0 +1,72 @@
+//! Logic related to a common database manager, component in charge of persisting data on disk. This is the base of more complex managers
+//! that can be used by both clients and towers.
+//!
+
+use rusqlite::ffi::{SQLITE_CONSTRAINT_FOREIGNKEY, SQLITE_CONSTRAINT_PRIMARYKEY};
+use rusqlite::{Connection, Error as SqliteError, ErrorCode, Params};
+
+/// Packs the errors than can raise when interacting with the underlying database.
+#[derive(Debug)]
+pub enum Error {
+    AlreadyExists,
+    MissingForeignKey,
+    MissingField,
+    NotFound,
+    Unknown(SqliteError),
+}
+
+pub trait DatabaseConnection {
+    fn get_connection(&self) -> &Connection;
+    fn get_mut_connection(&mut self) -> &mut Connection;
+}
+
+pub trait DatabaseManager: Sized {
+    fn create_tables(&mut self, tables: Vec<&str>) -> Result<(), SqliteError>;
+    fn store_data<P: Params>(&self, query: &str, params: P) -> Result<(), Error>;
+    fn remove_data<P: Params>(&self, query: &str, params: P) -> Result<(), Error>;
+    fn update_data<P: Params>(&self, query: &str, params: P) -> Result<(), Error>;
+}
+
+impl<T: DatabaseConnection> DatabaseManager for T {
+    /// Creates the database tables if not present.
+    fn create_tables(&mut self, tables: Vec<&str>) -> Result<(), SqliteError> {
+        let tx = self.get_mut_connection().transaction().unwrap();
+        for table in tables.iter() {
+            tx.execute(table, [])?;
+        }
+        tx.commit()
+    }
+
+    /// Generic method to store data into the database.
+    fn store_data<P: Params>(&self, query: &str, params: P) -> Result<(), Error> {
+        match self.get_connection().execute(query, params) {
+            Ok(_) => Ok(()),
+            Err(e) => match e {
+                SqliteError::SqliteFailure(ie, _) => match ie.code {
+                    ErrorCode::ConstraintViolation => match ie.extended_code {
+                        SQLITE_CONSTRAINT_FOREIGNKEY => Err(Error::MissingForeignKey),
+                        SQLITE_CONSTRAINT_PRIMARYKEY => Err(Error::AlreadyExists),
+                        _ => Err(Error::Unknown(e)),
+                    },
+                    _ => Err(Error::Unknown(e)),
+                },
+                _ => Err(Error::Unknown(e)),
+            },
+        }
+    }
+
+    /// Generic method to remove data from the database.
+    fn remove_data<P: Params>(&self, query: &str, params: P) -> Result<(), Error> {
+        match self.get_connection().execute(query, params).unwrap() {
+            0 => Err(Error::NotFound),
+            _ => Ok(()),
+        }
+    }
+
+    /// Generic method to update data from the database.
+    fn update_data<P: Params>(&self, query: &str, params: P) -> Result<(), Error> {
+        // Updating data is fundamentally the same as deleting it in terms of interface.
+        // A query is sent and either no row is modified or some rows are
+        self.remove_data(query, params)
+    }
+}

teos-common/src/lib.rs

@@ -2,30 +2,45 @@
 //!
 //! Functionality shared between users and towers.
 
+// FIXME: This is a temporary fix. See https://github.com/tokio-rs/prost/issues/661
+#[allow(clippy::derive_partial_eq_without_eq)]
+pub mod protos {
+    tonic::include_proto!("common.teos.v2");
+}
+
 pub mod appointment;
 pub mod constants;
 pub mod cryptography;
+pub mod dbm;
 pub mod errors;
+pub mod net;
 pub mod receipts;
+pub mod ser;
+pub mod test_utils;
 
 use std::fmt;
+use std::{convert::TryFrom, str::FromStr};
+
+use serde::{Deserialize, Serialize};
+use serde_json::json;
 
 use bitcoin::secp256k1::{Error, PublicKey};
 
 pub const USER_ID_LEN: usize = 33;
+pub use UserId as TowerId;
 
 /// User identifier. A wrapper around a [PublicKey].
-#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash, Serialize, Deserialize)]
 pub struct UserId(pub PublicKey);
 
 impl UserId {
     /// Encodes the user id in its byte representation.
-    pub fn serialize(&self) -> Vec<u8> {
+    pub fn to_vec(&self) -> Vec<u8> {
         self.0.serialize().to_vec()
     }
 
     /// Builds a user id from its byte representation.
-    pub fn deserialize(data: &[u8]) -> Result<Self, Error> {
+    pub fn from_slice(data: &[u8]) -> Result<Self, Error> {
         Ok(UserId(PublicKey::from_slice(data)?))
     }
 }
@@ -47,3 +62,126 @@ impl fmt::Display for UserId {
         write!(f, "{}", self.0)
     }
 }
+
+impl TryFrom<serde_json::Value> for UserId {
+    type Error = String;
+
+    fn try_from(value: serde_json::Value) -> Result<Self, Self::Error> {
+        match value {
+            serde_json::Value::String(s) => UserId::from_str(&s),
+            serde_json::Value::Array(mut a) => {
+                let param_count = a.len();
+                if param_count == 1 {
+                    UserId::try_from(a.pop().unwrap())
+                } else {
+                    Err(format!(
+                        "Unexpected json format. Expected a single parameter. Received: {param_count}"
+                    ))
+                }
+            }
+            serde_json::Value::Object(mut m) => {
+                let param_count = m.len();
+                if param_count > 1 {
+                    Err(format!(
+                        "Unexpected json format. Expected a single parameter. Received: {param_count}"
+                    ))
+                } else {
+                    UserId::try_from(json!(m
+                        .remove("user_id")
+                        .or_else(|| m.remove("tower_id"))
+                        .ok_or("user_id or tower_id not found")?))
+                }
+            }
+            _ => Err(format!(
+                "Unexpected request format. Expected: user_id/tower_id. Received: '{value}'"
+            )),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+    use std::collections::HashMap;
+
+    use crate::test_utils::get_random_user_id;
+
+    #[test]
+    fn try_from_json_string() {
+        let user_id = get_random_user_id();
+        assert_eq!(UserId::try_from(json!(user_id.to_string())), Ok(user_id));
+    }
+
+    #[test]
+    fn try_from_json_wrong_string() {
+        let user_id = "not_a_user_id";
+        assert!(matches!(
+            UserId::try_from(json!(user_id.to_string())),
+            Err(..)
+        ));
+    }
+
+    #[test]
+    fn try_from_json_array() {
+        let user_id = get_random_user_id();
+        assert_eq!(UserId::try_from(json!([user_id.to_string()])), Ok(user_id));
+    }
+
+    #[test]
+    fn try_from_json_array_empty() {
+        assert!(matches!(UserId::try_from(json!([])), Err(..)));
+    }
+
+    #[test]
+    fn try_from_json_array_too_many_elements() {
+        let user_id = get_random_user_id();
+        assert!(matches!(
+            UserId::try_from(json!([user_id.to_string(), user_id.to_string()])),
+            Err(..)
+        ));
+    }
+
+    #[test]
+    fn try_from_json_dict() {
+        let user_id = get_random_user_id();
+        assert_eq!(
+            UserId::try_from(json!(HashMap::from([("tower_id", user_id.to_string())]))),
+            Ok(user_id)
+        );
+        assert_eq!(
+            UserId::try_from(json!(HashMap::from([("user_id", user_id.to_string())]))),
+            Ok(user_id)
+        );
+    }
+
+    #[test]
+    fn try_from_json_empty_dict() {
+        assert!(matches!(
+            UserId::try_from(json!(HashMap::<String, serde_json::Value>::new())),
+            Err(..)
+        ));
+    }
+
+    #[test]
+    fn try_from_json_wrong_dict() {
+        let user_id = get_random_user_id();
+        assert!(matches!(
+            UserId::try_from(json!(HashMap::from([("random_key", user_id.to_string())]))),
+            Err(..)
+        ));
+    }
+
+    #[test]
+    fn try_from_json_dict_too_many_keys() {
+        let user_id = get_random_user_id();
+
+        assert!(matches!(
+            UserId::try_from(json!(HashMap::from([
+                ("tower_id", user_id.to_string()),
+                ("user_id", user_id.to_string())
+            ]))),
+            Err(..)
+        ));
+    }
+}

teos-common/src/net/http.rs

@@ -0,0 +1,29 @@
+pub enum Endpoint {
+    Register,
+    AddAppointment,
+    GetAppointment,
+    GetSubscriptionInfo,
+    Ping,
+}
+
+impl std::fmt::Display for Endpoint {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(
+            f,
+            "{}",
+            match self {
+                Endpoint::Register => "register",
+                Endpoint::AddAppointment => "add_appointment",
+                Endpoint::GetAppointment => "get_appointment",
+                Endpoint::GetSubscriptionInfo => "get_subscription_info",
+                Endpoint::Ping => "ping",
+            }
+        )
+    }
+}
+
+impl Endpoint {
+    pub fn path(&self) -> String {
+        format!("/{self}")
+    }
+}

teos-common/src/net/mod.rs

@@ -0,0 +1,116 @@
+pub mod http;
+
+use serde::Serialize;
+use std::fmt;
+
+/// Represents all types of teos network addresses
+#[derive(Clone, Serialize, Debug, PartialEq, Eq)]
+pub enum AddressType {
+    IpV4 = 0,
+    TorV3 = 1,
+}
+
+impl From<i32> for AddressType {
+    fn from(x: i32) -> Self {
+        match x {
+            0 => AddressType::IpV4,
+            1 => AddressType::TorV3,
+            x => panic!("Unknown address type {}", x),
+        }
+    }
+}
+
+impl std::str::FromStr for AddressType {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "ipv4" => Ok(AddressType::IpV4),
+            "torv3" => Ok(AddressType::TorV3),
+            _ => Err(format!("Unknown type: {s}")),
+        }
+    }
+}
+
+impl fmt::Display for AddressType {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let s = match self {
+            AddressType::IpV4 => "ipv4",
+            AddressType::TorV3 => "torv3",
+        };
+        write!(f, "{s}")
+    }
+}
+
+impl AddressType {
+    pub fn get_type(net_addr: &str) -> AddressType {
+        if net_addr.contains(".onion:") {
+            AddressType::TorV3
+        } else {
+            AddressType::IpV4
+        }
+    }
+
+    pub fn is_tor(&self) -> bool {
+        self == &AddressType::TorV3
+    }
+
+    pub fn is_clearnet(&self) -> bool {
+        self == &AddressType::IpV4
+    }
+}
+
+#[derive(Clone, Serialize, Debug, PartialEq, Eq)]
+pub struct NetAddr {
+    net_addr: String,
+    #[serde(skip)]
+    addr_type: AddressType,
+}
+
+impl NetAddr {
+    pub fn new(net_addr: String) -> Self {
+        NetAddr {
+            addr_type: AddressType::get_type(&net_addr),
+            net_addr,
+        }
+    }
+
+    pub fn net_addr(&self) -> &str {
+        &self.net_addr
+    }
+
+    pub fn addr_type(&self) -> &AddressType {
+        &self.addr_type
+    }
+
+    pub fn is_onion(&self) -> bool {
+        self.addr_type().is_tor()
+    }
+}
+
+#[cfg(test)]
+pub mod tests {
+    use super::*;
+
+    pub const TORV3_ADDR: &str =
+        "recnedb7xfhzjdrcgxongzli3a6qyrv5jwgowoho3v5g3rwk7kkglrid.onion:9814";
+    pub const IPV4_ADDR: &str = "teos.talaia.watch:9814";
+
+    #[test]
+    fn test_get_type() {
+        assert_eq!(AddressType::get_type(TORV3_ADDR), AddressType::TorV3);
+        assert_eq!(AddressType::get_type(IPV4_ADDR), AddressType::IpV4);
+    }
+
+    #[test]
+    fn test_is_tor() {
+        assert!(NetAddr::new(TORV3_ADDR.to_owned()).addr_type.is_tor());
+        assert!(!NetAddr::new(IPV4_ADDR.to_owned()).addr_type.is_tor());
+    }
+
+    #[test]
+    fn test_is_clearnet() {
+        assert!(!NetAddr::new(TORV3_ADDR.to_owned()).addr_type.is_clearnet());
+        assert!(NetAddr::new(IPV4_ADDR.to_owned()).addr_type.is_clearnet());
+    }
+}

teos-common/src/receipts.rs

@@ -1,27 +1,66 @@
 //! Receipts issued  by towers and handed to users as commitment proof.
 
+use serde::Serialize;
+
 use bitcoin::secp256k1::SecretKey;
 
 use crate::{cryptography, UserId};
 
-#[derive(Debug)]
+/// Proof that a user has registered with a tower. This serves two purposes:
+///
+/// - First, the user is able to prove that the tower agreed on providing a service. If a tower refuses to accept appointments
+///   from a user (claiming the subscription has expired) but the expiry time has still not passed and the tower cannot
+///   provide the relevant appointments signed by the user, it means it is cheating.
+/// - Second, it serves as proof, alongside an appointment receipt, that an appointment was not fulfilled. A registration receipt
+///   specifies a subscription period (`subscription_start` - `subscription_expiry`) and the appointment a `start_block` so inclusion
+///   can be proved.
+///
+/// TODO: / DISCUSS: In order to minimize the amount of receipts the user has to store, the tower could batch subscription receipts
+/// as long as the user info is still known. That is, if a user has a subscription with range (S, E) and the user renews the subscription
+/// before the tower wipes their data, then the tower can create a new receipt with (S, E') for E' > E instead of a second receipt (E, E').
+// Notice this only applies as long as there is no gap between the two subscriptions.
+#[derive(Serialize, Debug, Eq, PartialEq, Clone)]
 pub struct RegistrationReceipt {
     user_id: UserId,
     available_slots: u32,
+    subscription_start: u32,
     subscription_expiry: u32,
+    #[serde(rename = "subscription_signature")]
     signature: Option<String>,
 }
 
 impl RegistrationReceipt {
-    pub fn new(user_id: UserId, available_slots: u32, subscription_expiry: u32) -> Self {
+    pub fn new(
+        user_id: UserId,
+        available_slots: u32,
+        subscription_start: u32,
+        subscription_expiry: u32,
+    ) -> Self {
         RegistrationReceipt {
             user_id,
             available_slots,
+            subscription_start,
             subscription_expiry,
             signature: None,
         }
     }
 
+    pub fn with_signature(
+        user_id: UserId,
+        available_slots: u32,
+        subscription_start: u32,
+        subscription_expiry: u32,
+        signature: String,
+    ) -> Self {
+        RegistrationReceipt {
+            user_id,
+            available_slots,
+            subscription_start,
+            subscription_expiry,
+            signature: Some(signature),
+        }
+    }
+
     pub fn user_id(&self) -> UserId {
         self.user_id
     }
@@ -30,6 +69,10 @@ impl RegistrationReceipt {
         self.available_slots
     }
 
+    pub fn subscription_start(&self) -> u32 {
+        self.subscription_start
+    }
+
     pub fn subscription_expiry(&self) -> u32 {
         self.subscription_expiry
     }
@@ -38,21 +81,33 @@ impl RegistrationReceipt {
         self.signature.clone()
     }
 
-    pub fn serialize(&self) -> Vec<u8> {
+    pub fn to_vec(&self) -> Vec<u8> {
         let mut ser = Vec::new();
-        ser.extend_from_slice(&self.user_id.serialize());
+        ser.extend_from_slice(&self.user_id.to_vec());
         ser.extend_from_slice(&self.available_slots.to_be_bytes());
+        ser.extend_from_slice(&self.subscription_start.to_be_bytes());
         ser.extend_from_slice(&self.subscription_expiry.to_be_bytes());
 
         ser
     }
 
     pub fn sign(&mut self, sk: &SecretKey) {
-        // TODO: Check if there's any case where this can actually fail. Don't unwrap if so.
-        self.signature = Some(cryptography::sign(&self.serialize(), sk).unwrap());
+        self.signature = Some(cryptography::sign(&self.to_vec(), sk));
+    }
+
+    pub fn verify(&self, id: &UserId) -> bool {
+        if let Some(signature) = self.signature() {
+            cryptography::verify(&self.to_vec(), &signature, &id.0)
+        } else {
+            false
+        }
     }
 }
-#[derive(Debug)]
+
+/// Proof that a certain state was backed up with the tower.
+///
+/// Appointment receipts can be used alongside a registration receipt that covers it, and on chain data (a breach not being reacted with a penalty), to prove a tower has not reacted to a channel breach.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize)]
 pub struct AppointmentReceipt {
     user_signature: String,
     start_block: u32,
@@ -68,6 +123,14 @@ impl AppointmentReceipt {
         }
     }
 
+    pub fn with_signature(user_signature: String, start_block: u32, signature: String) -> Self {
+        AppointmentReceipt {
+            user_signature,
+            start_block,
+            signature: Some(signature),
+        }
+    }
+
     pub fn user_signature(&self) -> &str {
         &self.user_signature
     }
@@ -80,7 +143,7 @@ impl AppointmentReceipt {
         self.signature.clone()
     }
 
-    pub fn serialize(&self) -> Vec<u8> {
+    pub fn to_vec(&self) -> Vec<u8> {
         let mut ser = Vec::new();
         ser.extend_from_slice(self.user_signature.as_bytes());
         ser.extend_from_slice(&self.start_block.to_be_bytes());
@@ -89,7 +152,14 @@ impl AppointmentReceipt {
     }
 
     pub fn sign(&mut self, sk: &SecretKey) {
-        // TODO: Check if there's any case where this can actually fail. Don't unwrap if so.
-        self.signature = Some(cryptography::sign(&self.serialize(), sk).unwrap());
+        self.signature = Some(cryptography::sign(&self.to_vec(), sk));
+    }
+
+    pub fn verify(&self, id: &UserId) -> bool {
+        if let Some(signature) = self.signature() {
+            cryptography::verify(&self.to_vec(), &signature, &id.0)
+        } else {
+            false
+        }
     }
 }

teos-common/src/ser.rs

@@ -0,0 +1,146 @@
+use std::collections::HashSet;
+
+use serde::{ser::SerializeSeq, Serializer};
+
+use crate::appointment::Locator;
+
+pub fn serialize_locators<S>(hs: &HashSet<Locator>, s: S) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+{
+    let mut seq = s.serialize_seq(Some(hs.len()))?;
+    for element in hs.iter() {
+        seq.serialize_element(&hex::encode(element))?;
+    }
+    seq.end()
+}
+
+pub mod serde_be {
+    use super::*;
+    use serde::de::{self, Deserializer};
+
+    pub fn serialize<S>(v: &[u8], s: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let mut v = v.to_owned();
+        v.reverse();
+        hex::serialize(v, s)
+    }
+
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<Vec<u8>, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        struct BEVisitor;
+
+        impl<'de> de::Visitor<'de> for BEVisitor {
+            type Value = Vec<u8>;
+
+            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+                formatter.write_str("a hex encoded string")
+            }
+
+            fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+            where
+                E: de::Error,
+            {
+                let mut v =
+                    hex::decode(v).map_err(|_| E::custom("cannot deserialize the given value"))?;
+                v.reverse();
+                Ok(v)
+            }
+        }
+
+        deserializer.deserialize_any(BEVisitor)
+    }
+}
+
+pub mod serde_vec_bytes {
+    use super::*;
+    use serde::de::{self, Deserializer, SeqAccess};
+
+    pub fn serialize<S>(v: &[Vec<u8>], s: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let mut seq = s.serialize_seq(Some(v.len()))?;
+        for element in v.iter() {
+            seq.serialize_element(&hex::encode(element))?;
+        }
+        seq.end()
+    }
+
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<Vec<Vec<u8>>, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        struct VecVisitor;
+
+        impl<'de> de::Visitor<'de> for VecVisitor {
+            type Value = Vec<Vec<u8>>;
+
+            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+                formatter.write_str("a hex encoded string")
+            }
+
+            fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
+            where
+                A: SeqAccess<'de>,
+            {
+                let mut result = Vec::new();
+                while let Some(v) = seq.next_element::<String>()? {
+                    result
+                        .push(hex::decode(v).map_err(|_| {
+                            de::Error::custom("cannot deserialize the given value")
+                        })?);
+                }
+
+                Ok(result)
+            }
+        }
+
+        deserializer.deserialize_any(VecVisitor)
+    }
+}
+
+pub mod serde_status {
+    use super::*;
+    use serde::de::{self, Deserializer};
+    use std::str::FromStr;
+
+    use crate::appointment::AppointmentStatus;
+
+    pub fn serialize<S>(status: &i32, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_str(&AppointmentStatus::from(*status).to_string())
+    }
+
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<i32, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        struct StatusVisitor;
+
+        impl<'de> de::Visitor<'de> for StatusVisitor {
+            type Value = i32;
+
+            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+                formatter.write_str("a string containing the status")
+            }
+
+            fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+            where
+                E: de::Error,
+            {
+                let status = AppointmentStatus::from_str(v)
+                    .map_err(|_| E::custom("given status is unknown"))?;
+                Ok(status as i32)
+            }
+        }
+
+        deserializer.deserialize_any(StatusVisitor)
+    }
+}

teos-common/src/test_utils.rs

@@ -0,0 +1,100 @@
+use std::convert::TryInto;
+
+use bitcoin::script::PushBytesBuf;
+use hex::FromHex;
+use rand::distributions::Standard;
+use rand::prelude::Distribution;
+use rand::Rng;
+
+use bitcoin::hashes::Hash;
+use bitcoin::secp256k1::SecretKey;
+use bitcoin::{consensus, Amount, ScriptBuf, Transaction, TxOut, Txid};
+
+use crate::appointment::{Appointment, Locator};
+use crate::cryptography;
+use crate::receipts::{AppointmentReceipt, RegistrationReceipt};
+use crate::UserId;
+
+pub static TXID_HEX: &str = "338bda693c4a26e0d41a01f7f2887aaf48bf0bdf93e6415c9110b29349349d3e";
+pub static TX_HEX: &str =  "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";
+
+pub fn get_random_int<T>() -> T
+where
+    Standard: Distribution<T>,
+{
+    let mut rng = rand::thread_rng();
+    rng.gen()
+}
+
+pub fn get_random_user_id() -> UserId {
+    let (_, pk) = cryptography::get_random_keypair();
+
+    UserId(pk)
+}
+
+pub fn get_random_locator() -> Locator {
+    let mut rng = rand::thread_rng();
+
+    Locator::from_slice(&rng.gen::<[u8; 16]>()).unwrap()
+}
+
+pub fn generate_random_appointment(dispute_txid: Option<&Txid>) -> Appointment {
+    let dispute_txid = match dispute_txid {
+        Some(l) => *l,
+        None => {
+            let prev_txid_bytes = cryptography::get_random_bytes(32);
+            Txid::from_slice(&prev_txid_bytes).unwrap()
+        }
+    };
+
+    let tx_bytes = Vec::from_hex(TX_HEX).unwrap();
+    let mut penalty_tx: Transaction = consensus::deserialize(&tx_bytes).unwrap();
+    let size = get_random_int::<usize>() % 81;
+    let mut push_bytes_buf = PushBytesBuf::new();
+    PushBytesBuf::extend_from_slice(&mut push_bytes_buf, &cryptography::get_random_bytes(size))
+        .unwrap();
+    let script_pubkey = ScriptBuf::new_op_return(push_bytes_buf);
+
+    // Append a random-sized OP_RETURN to make each transcation random in size.
+    penalty_tx.output.push(TxOut {
+        value: Amount::from_sat(0),
+        script_pubkey,
+    });
+
+    let mut raw_locator: [u8; 16] = cryptography::get_random_bytes(16).try_into().unwrap();
+    raw_locator.copy_from_slice(&dispute_txid[..16]);
+    let locator = Locator::from_slice(&raw_locator).unwrap();
+
+    let encrypted_blob = cryptography::encrypt(&penalty_tx, &dispute_txid).unwrap();
+    Appointment::new(locator, encrypted_blob, get_random_int())
+}
+
+pub fn get_random_registration_receipt() -> RegistrationReceipt {
+    let (sk, _) = cryptography::get_random_keypair();
+    let start = get_random_int();
+    let mut receipt =
+        RegistrationReceipt::new(get_random_user_id(), get_random_int(), start, start + 420);
+    receipt.sign(&sk);
+
+    receipt
+}
+
+pub fn get_registration_receipt_from_previous(r: &RegistrationReceipt) -> RegistrationReceipt {
+    let (sk, _) = cryptography::get_random_keypair();
+    let mut receipt = RegistrationReceipt::new(
+        r.user_id(),
+        r.available_slots() + 1 + get_random_int::<u8>() as u32,
+        r.subscription_start(),
+        r.subscription_expiry() + 1 + get_random_int::<u8>() as u32,
+    );
+    receipt.sign(&sk);
+
+    receipt
+}
+
+pub fn get_random_appointment_receipt(tower_sk: SecretKey) -> AppointmentReceipt {
+    let mut receipt = AppointmentReceipt::new("user_sig".into(), 42);
+    receipt.sign(&tower_sk);
+
+    receipt
+}

teos/Cargo.toml

@@ -1,9 +1,9 @@
 [package]
 name = "teos"
-version = "0.0.1"
+version = "0.2.0"
 authors = ["Sergi Delgado Segura <sergi.delgado.s@gmail.com>"]
 license = "MIT"
-edition = "2018"
+edition = "2021"
 default-run="teosd"
 
 [[bin]]
@@ -19,33 +19,36 @@ path = "src/main.rs"
 hex = { version = "0.4.3", features = [ "serde" ] }
 home = "0.5.3"
 log = "0.4"
-prost = "0.9"
+prost = "0.12"
+rcgen = { version = "0.13.1", features = ["pem", "x509-parser"] }
 rusqlite = { version = "0.26.0", features = [ "bundled", "limits" ] }
 serde = "1.0.130"
 serde_json = "1.0"
 simple_logger = "2.1.0"
 structopt = "0.3"
 toml = "0.5"
-tonic = "0.6"
+tonic = { version = "0.11", features = [ "tls", "transport" ] }
 tokio = { version = "1.5", features = [ "rt-multi-thread" ] }
 triggered = "0.1.2"
-warp = "0.3.2"
+warp = "0.3.5"
+torut = "0.2.1"
+base64 = "0.22.1"
 
 # Bitcoin and Lightning
-bitcoin = { version = "0.27", features = [ "base64" ] }
-bitcoincore-rpc = "0.14.0"
-lightning = "0.0.104"
-lightning-net-tokio = "0.0.104"
-lightning-block-sync = { version = "0.0.104", features = [ "rpc-client" ] }
+bitcoin = { version = "0.32.0" }
+bitcoincore-rpc = "0.19.0"
+lightning = "0.1.0"
+lightning-net-tokio = "0.1.0"
+lightning-block-sync = { version = "0.1.0", features = [ "rpc-client" ] }
 
 # Local
 teos-common = { path = "../teos-common" }
 
 [build-dependencies]
-tonic-build = "0.6"
+tonic-build = "0.11"
 
 [dev-dependencies]
-chunked_transfer = "1.4"
-rand = "0.8.4"
 jsonrpc-http-server = "17.1.0"
-tokio-stream = { version = "0.1.5", features = [ "net" ] }
+rand = "0.8.4"
+tempdir = "0.3.7"
+tokio-stream = { version = "0.1.5", features = [ "net" ] }

teos/build.rs

@@ -1,37 +1,28 @@
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     tonic_build::configure()
+        .extern_path(".common.teos.v2", "::teos-common::protos")
         .type_attribute(".", "#[derive(serde::Serialize, serde::Deserialize)]")
-        .type_attribute("AppointmentData.appointment_data", "#[serde(untagged)]")
-        .field_attribute("AppointmentData.appointment_data", "#[serde(flatten)]")
-        .field_attribute("appointment_data", "#[serde(rename = \"appointment\")]")
         .field_attribute("user_id", "#[serde(with = \"hex::serde\")]")
         .field_attribute("tower_id", "#[serde(with = \"hex::serde\")]")
-        .field_attribute("locator", "#[serde(with = \"hex::serde\")]")
-        .field_attribute("encrypted_blob", "#[serde(with = \"hex::serde\")]")
-        .field_attribute("tx", "#[serde(with = \"hex::serde\")]")
-        .field_attribute(
-            "locators",
-            "#[serde(serialize_with = \"crate::api::http::serialize_vec_bytes\")]",
-        )
         .field_attribute(
             "user_ids",
-            "#[serde(serialize_with = \"crate::api::http::serialize_vec_bytes\")]",
+            "#[serde(serialize_with = \"teos_common::ser::serde_vec_bytes::serialize\")]",
         )
         .field_attribute(
             "GetUserResponse.appointments",
-            "#[serde(serialize_with = \"crate::api::http::serialize_vec_bytes\")]",
+            "#[serde(serialize_with = \"teos_common::ser::serde_vec_bytes::serialize\")]",
         )
         .field_attribute(
-            "GetAppointmentResponse.status",
-            "#[serde(with = \"crate::api::serde_status\")]",
+            "NetworkAddress.address_type",
+            "#[serde(rename = \"type\", with = \"crate::api::serde::serde_address_type\")]",
         )
         .compile(
             &[
-                "proto/teos/appointment.proto",
-                "proto/teos/tower_services.proto",
-                "proto/teos/user.proto",
+                "proto/teos/v2/appointment.proto",
+                "proto/teos/v2/tower_services.proto",
+                "proto/teos/v2/user.proto",
             ],
-            &["proto/teos"],
+            &["proto/teos/v2", "../teos-common/proto/"],
         )?;
 
     Ok(())

teos/proto/teos/appointment.proto

@@ -1,81 +0,0 @@
-syntax = "proto3";
-package teos.v2;
-
-message Appointment {
-  /*
-  Contains the basic information about an appointment (Watcher) and it's used for messages like
-  AddAppointmentRequest or encapsulated inside AppointmentData for GetAppointmentResponse
-  */
-
-  bytes locator = 1;
-  bytes encrypted_blob = 2;
-  uint32 to_self_delay = 3;
-
-}
-
-message Tracker {
-  // It's the equivalent of an appointment message from data held by the Responder.
-
-  bytes dispute_txid = 1;
-  bytes penalty_txid = 2;
-  bytes penalty_rawtx = 3;
-}
-
-message AppointmentData {
-  /*
-  Encapsulates the data for a GetAppointmentResponse, given it can be an appointment (data is on the Watcher) or a
-  tracker (data is on the Responder).
-  */
-
-  oneof appointment_data {
-    Appointment appointment = 1;
-    Tracker tracker = 2;
-  }
-}
-
-message AddAppointmentRequest {
-  // Request to add an appointment to the backend, contains the appointment data and the user signature.
-
-  Appointment appointment = 1;
-  string signature = 2;
-}
-
-message AddAppointmentResponse {
-  /*
-  Response to an AddAppointmentRequest, contains the locator to identify the added appointment, the tower signature,
-  the block at which the tower has started (or will start) watching for the appointment, and the updated subscription
-  information.
-   */
-
-  bytes locator = 1;
-  uint32 start_block = 2;
-  string signature = 3;
-  uint32 available_slots = 4;
-  uint32 subscription_expiry = 5;
-}
-
-message GetAppointmentRequest {
-  // Request to get information about an appointment. Contains the appointment locator and a signature by the user.
-
-  bytes locator = 1;
-  string signature = 2;
-}
-
-message GetAppointmentResponse {
-  // Response to a GetAppointmentRequest. Contains the appointment data encapsulated in an AppointmentData message.
-
-  AppointmentData appointment_data = 1;
-  enum AppointmentStatus {
-    NOT_FOUND = 0;
-    BEING_WATCHED = 1;
-    DISPUTE_RESPONDED = 2;
-
-  }
-  AppointmentStatus status = 2;
-}
-
-message GetAllAppointmentsResponse {
-  // Response with data about all the appointments in the tower. 
-  
-  repeated AppointmentData appointments = 1;
-}

teos/proto/teos/user.proto

@@ -1,51 +0,0 @@
-syntax = "proto3";
-package teos.v2;
-
-message RegisterRequest {
-  // Requests a user registration with the tower. Contains the user id in the form of a compressed ECDSA public key.
-
-  bytes user_id = 1;
-}
-
-message RegisterResponse {
-  // Response to a RegisterRequest, contains the registration information alongside the tower signature of the agreement.
-
-  bytes user_id = 1;
-  uint32 available_slots = 2;
-  uint32 subscription_expiry = 3;
-  string subscription_signature = 4;
-}
-
-message GetUserRequest {
-  // Request to get information about a specific user. Contains the user id.
-
-  bytes user_id = 1;
-}
-
-message GetUserResponse {
-  // Response with the information the tower has about a specific user
-
-  uint32 available_slots = 1;
-  uint32 subscription_expiry = 2;
-  repeated bytes appointments = 3;
-}
-
-message GetUsersResponse {
-  // Response with information about all the users registered with the tower. Contains a list of user ids.
-
-  repeated bytes user_ids = 1;
-}
-
-message GetSubscriptionInfoRequest {
-    // Request to get a specific user's subscription info.
-
-    string signature = 1;
-}
-
-message GetSubscriptionInfoResponse {
-  // Response with the information the tower has about a specific user
-
-  uint32 available_slots = 1;
-  uint32 subscription_expiry = 2;
-  repeated bytes locators = 3;
-}

teos/proto/teos/v2/appointment.proto

@@ -0,0 +1,22 @@
+syntax = "proto3";
+package teos.v2;
+
+import "common/teos/v2/appointment.proto";
+
+message GetAppointmentsRequest {
+  // Request the information of appointments with specific locator.
+
+  bytes locator = 1;
+}
+
+message GetAppointmentsResponse {
+  // Response with the information of all appointments with a specific locator.
+
+  repeated common.teos.v2.AppointmentData appointments = 1;
+}
+
+message GetAllAppointmentsResponse {
+  // Response with data about all the appointments in the tower. 
+  
+  repeated common.teos.v2.AppointmentData appointments = 1;
+}

teos/proto/teos/v2/tower_services.proto

@@ -3,31 +3,46 @@ package teos.v2;
 
 import "appointment.proto";
 import "user.proto";
+import "common/teos/v2/appointment.proto";
+import "common/teos/v2/user.proto";
 import "google/protobuf/empty.proto";
 
+message NetworkAddress {
+  // Tower public API endpoint.
+  enum AddressType {
+    IpV4 = 0;
+    TorV3 = 1;
+  }
+  AddressType address_type = 1;
+  string address = 2;
+  uint32 port = 3;
+
+}
+
 message GetTowerInfoResponse {
   // Response with information about the tower.
-
   bytes tower_id = 1;
   uint32 n_registered_users = 2;
   uint32 n_watcher_appointments = 3;
   uint32 n_responder_trackers = 4;
   bool bitcoind_reachable = 5;
+  repeated NetworkAddress addresses = 6;
 }
 
 service PublicTowerServices {
   // Public tower services, only reachable from the public API.
 
-  rpc register(RegisterRequest) returns (RegisterResponse) {}
-  rpc add_appointment(AddAppointmentRequest) returns (AddAppointmentResponse) {}
-  rpc get_appointment(GetAppointmentRequest) returns (GetAppointmentResponse) {}
-  rpc get_subscription_info(GetSubscriptionInfoRequest) returns (GetSubscriptionInfoResponse) {}
+  rpc register(common.teos.v2.RegisterRequest) returns (common.teos.v2.RegisterResponse) {}
+  rpc add_appointment(common.teos.v2.AddAppointmentRequest) returns (common.teos.v2.AddAppointmentResponse) {}
+  rpc get_appointment(common.teos.v2.GetAppointmentRequest) returns (common.teos.v2.GetAppointmentResponse) {}
+  rpc get_subscription_info(common.teos.v2.GetSubscriptionInfoRequest) returns (common.teos.v2.GetSubscriptionInfoResponse) {}
 }
 
 service PrivateTowerServices {
   // Private tower services, only reachable from the private API.
 
   rpc get_all_appointments(google.protobuf.Empty) returns (GetAllAppointmentsResponse) {}
+  rpc get_appointments(GetAppointmentsRequest) returns (GetAppointmentsResponse) {}
   rpc get_tower_info(google.protobuf.Empty) returns (GetTowerInfoResponse) {}
   rpc get_users(google.protobuf.Empty) returns (GetUsersResponse) {}
   rpc get_user(GetUserRequest) returns (GetUserResponse) {}

teos/proto/teos/v2/user.proto

@@ -0,0 +1,22 @@
+syntax = "proto3";
+package teos.v2;
+
+message GetUserRequest {
+  // Request to get information about a specific user. Contains the user id.
+
+  bytes user_id = 1;
+}
+
+message GetUserResponse {
+  // Response with the information the tower has about a specific user
+
+  uint32 available_slots = 1;
+  uint32 subscription_expiry = 2;
+  repeated bytes appointments = 3;
+}
+
+message GetUsersResponse {
+  // Response with information about all the users registered with the tower. Contains a list of user ids.
+
+  repeated bytes user_ids = 1;
+}

teos/src/api/http.rs

@@ -1,15 +1,17 @@
-use serde::{ser::SerializeSeq, Deserialize, Serialize, Serializer};
+use serde::{Deserialize, Serialize};
 use std::convert::Infallible;
 use std::error::Error;
 use std::net::SocketAddr;
+use tokio::time::Duration;
 use tonic::transport::Channel;
-use triggered::Listener;
+use triggered::{Listener, Trigger};
 use warp::{http::StatusCode, reject, reply, Filter, Rejection, Reply};
 
 use teos_common::appointment::LOCATOR_LEN;
+use teos_common::net::http::Endpoint;
+use teos_common::protos as common_msgs;
 use teos_common::{errors, USER_ID_LEN};
 
-use crate::protos as msgs;
 use crate::protos::public_tower_services_client::PublicTowerServicesClient;
 
 // TODO: Limit the body length for /add_appointment should not be needed, since slots are consumed proportionally to it.
@@ -34,14 +36,14 @@ impl ApiError {
 
     fn missing_field(field_name: &str) -> Rejection {
         reject::custom(Self::new(
-            format!("missing field `{}`", field_name),
+            format!("missing field `{field_name}`"),
             errors::MISSING_FIELD,
         ))
     }
 
     fn empty_field(field_name: &str) -> Rejection {
         reject::custom(Self::new(
-            format!("`{}` field is empty", field_name),
+            format!("`{field_name}` field is empty"),
             errors::EMPTY_FIELD,
         ))
     }
@@ -49,25 +51,13 @@ impl ApiError {
     fn wrong_field_length(field_name: &str, field_size: usize, expected_size: usize) -> Rejection {
         reject::custom(Self::new(
             format!(
-                "Wrong `{}` field size. Expected {}, received {}",
-                field_name, expected_size, field_size
+                "Wrong `{field_name}` field size. Expected {expected_size}, received {field_size}"
             ),
             errors::WRONG_FIELD_SIZE,
         ))
     }
 }
 
-pub fn serialize_vec_bytes<S>(v: &[Vec<u8>], s: S) -> Result<S::Ok, S::Error>
-where
-    S: Serializer,
-{
-    let mut seq = s.serialize_seq(Some(v.len()))?;
-    for element in v.iter() {
-        seq.serialize_element(&hex::encode(element))?;
-    }
-    seq.end()
-}
-
 fn with_grpc(
     grpc_endpoint: PublicTowerServicesClient<Channel>,
 ) -> impl Filter<Extract = (PublicTowerServicesClient<Channel>,), Error = Infallible> + Clone {
@@ -107,13 +97,13 @@ fn parse_grpc_response<T: serde::Serialize>(
     match result {
         Ok(r) => {
             let inner = r.into_inner();
-            log::info!("Request succeeded");
+            log::debug!("Request succeeded");
             log::debug!("Response: {}", serde_json::json!(inner));
             (reply::json(&inner), StatusCode::OK)
         }
         Err(s) => {
             let (status_code, error_code) = match_status(&s);
-            log::info!("Request failed, error_code={}", error_code);
+            log::debug!("Request failed, error_code={error_code}");
             log::debug!("Response: {}", serde_json::json!(s.message()));
             (
                 reply::json(&ApiError::new(s.message().into(), error_code)),
@@ -124,14 +114,14 @@ fn parse_grpc_response<T: serde::Serialize>(
 }
 
 async fn register(
-    req: msgs::RegisterRequest,
+    req: common_msgs::RegisterRequest,
     addr: Option<std::net::SocketAddr>,
     mut grpc_conn: PublicTowerServicesClient<Channel>,
 ) -> std::result::Result<impl Reply, Rejection> {
-    match addr {
-        Some(a) => log::info!("Received register request from {}", a),
-        None => log::info!("Received register request from unknown address"),
-    }
+    log::debug!(
+        "Received a register request from {}",
+        addr.map_or("an unknown address".to_owned(), |a| a.to_string())
+    );
 
     let user_id = req.user_id.clone();
     if user_id.is_empty() {
@@ -150,14 +140,14 @@ async fn register(
 }
 
 async fn add_appointment(
-    req: msgs::AddAppointmentRequest,
+    req: common_msgs::AddAppointmentRequest,
     addr: Option<std::net::SocketAddr>,
     mut grpc_conn: PublicTowerServicesClient<Channel>,
 ) -> std::result::Result<impl Reply, Rejection> {
-    match addr {
-        Some(a) => log::info!("Received add_appointment request from {}", a),
-        None => log::info!("Received add_appointment request from unknown address"),
-    }
+    log::debug!(
+        "Received an add_appointment request from {}",
+        addr.map_or("an unknown address".to_owned(), |a| a.to_string())
+    );
 
     if let Some(a) = &req.appointment {
         if a.locator.is_empty() {
@@ -182,14 +172,14 @@ async fn add_appointment(
 }
 
 async fn get_appointment(
-    req: msgs::GetAppointmentRequest,
+    req: common_msgs::GetAppointmentRequest,
     addr: Option<std::net::SocketAddr>,
     mut grpc_conn: PublicTowerServicesClient<Channel>,
 ) -> std::result::Result<impl Reply, Rejection> {
-    match addr {
-        Some(a) => log::info!("Received get_appointment request from {}", a),
-        None => log::info!("Received get_appointment request from unknown address"),
-    }
+    log::debug!(
+        "Received an get_appointment request from {}",
+        addr.map_or("an unknown address".to_owned(), |a| a.to_string())
+    );
 
     if req.locator.is_empty() {
         return Err(ApiError::empty_field("locator"));
@@ -210,14 +200,14 @@ async fn get_appointment(
 }
 
 async fn get_subscription_info(
-    req: msgs::GetSubscriptionInfoRequest,
+    req: common_msgs::GetSubscriptionInfoRequest,
     addr: Option<std::net::SocketAddr>,
     mut grpc_conn: PublicTowerServicesClient<Channel>,
 ) -> std::result::Result<impl Reply, Rejection> {
-    match addr {
-        Some(a) => log::info!("Received get_subscription_info request from {}", a),
-        None => log::info!("Received get_subscription_info request from unknown address"),
-    }
+    log::debug!(
+        "Received an get_subscription_info request from {}",
+        addr.map_or("an unknown address".to_owned(), |a| a.to_string())
+    );
 
     if req.signature.is_empty() {
         return Err(ApiError::empty_field("signature"));
@@ -227,32 +217,40 @@ async fn get_subscription_info(
     Ok(reply::with_status(body, status))
 }
 
+async fn ping(addr: Option<SocketAddr>) -> Result<impl Reply, Rejection> {
+    log::debug!(
+        "Received a ping request from {}",
+        addr.map_or("an unknown address".to_owned(), |a| a.to_string())
+    );
+    Ok(reply::reply())
+}
+
 fn router(
     grpc_conn: PublicTowerServicesClient<Channel>,
-) -> impl Filter<Extract = impl Reply, Error = Rejection> + Clone {
+) -> impl Filter<Extract = (impl Reply,), Error = Rejection> + Clone {
     let register = warp::post()
-        .and(warp::path("register"))
+        .and(warp::path(Endpoint::Register.to_string()))
         .and(warp::body::content_length_limit(REGISTER_BODY_LEN).and(warp::body::json()))
         .and(warp::addr::remote())
         .and(with_grpc(grpc_conn.clone()))
         .and_then(register);
 
     let add_appointment = warp::post()
-        .and(warp::path("add_appointment"))
+        .and(warp::path(Endpoint::AddAppointment.to_string()))
         .and(warp::body::content_length_limit(ADD_APPOINTMENT_BODY_LEN).and(warp::body::json()))
         .and(warp::addr::remote())
         .and(with_grpc(grpc_conn.clone()))
         .and_then(add_appointment);
 
     let get_appointment = warp::post()
-        .and(warp::path("get_appointment"))
+        .and(warp::path(Endpoint::GetAppointment.to_string()))
         .and(warp::body::content_length_limit(GET_APPOINTMENT_BODY_LEN).and(warp::body::json()))
         .and(warp::addr::remote())
         .and(with_grpc(grpc_conn.clone()))
         .and_then(get_appointment);
 
     let get_subscription_info = warp::post()
-        .and(warp::path("get_subscription_info"))
+        .and(warp::path(Endpoint::GetSubscriptionInfo.to_string()))
         .and(
             warp::body::content_length_limit(GET_SUBSCRIPTION_INFO_BODY_LEN)
                 .and(warp::body::json()),
@@ -261,10 +259,16 @@ fn router(
         .and(with_grpc(grpc_conn))
         .and_then(get_subscription_info);
 
+    let ping = warp::get()
+        .and(warp::path(Endpoint::Ping.to_string()))
+        .and(warp::addr::remote())
+        .and_then(ping);
+
     register
         .or(add_appointment)
         .or(get_appointment)
         .or(get_subscription_info)
+        .or(ping)
         .recover(handle_rejection)
 }
 
@@ -298,10 +302,24 @@ async fn handle_rejection(err: Rejection) -> Result<impl Reply, Rejection> {
     }
 }
 
-pub async fn serve(http_bind: SocketAddr, grpc_bind: String, shutdown_signal: Listener) {
-    let grpc_conn = PublicTowerServicesClient::connect(grpc_bind).await.unwrap();
-    let (_, server) = warp::serve(router(grpc_conn))
-        .bind_with_graceful_shutdown(http_bind, async { shutdown_signal.await });
+pub async fn serve(
+    http_bind: SocketAddr,
+    grpc_bind: SocketAddr,
+    service_ready: Trigger,
+    shutdown_signal: Listener,
+) {
+    let grpc_conn = loop {
+        match PublicTowerServicesClient::connect(format!("http://{grpc_bind}")).await {
+            Ok(conn) => break conn,
+            Err(_) => {
+                log::error!("Cannot connect to the gRPC server. Retrying shortly");
+                tokio::time::sleep(Duration::from_secs(1)).await;
+            }
+        }
+    };
+    let (_, server) =
+        warp::serve(router(grpc_conn)).bind_with_graceful_shutdown(http_bind, shutdown_signal);
+    service_ready.trigger();
     server.await
 }
 
@@ -317,7 +335,7 @@ mod test_helpers {
 
     use crate::api::internal::InternalAPI;
     use crate::protos::public_tower_services_server::PublicTowerServicesServer;
-    use crate::test_utils::{create_api_with_config, ApiConfig};
+    use crate::test_utils::{create_api_with_config, ApiConfig, BitcoindStopper};
 
     pub(crate) enum RequestBody<'a> {
         Jsonify(&'a str),
@@ -328,8 +346,8 @@ mod test_helpers {
 
     pub(crate) async fn run_tower_in_background_with_config(
         api_config: ApiConfig,
-    ) -> (SocketAddr, Arc<InternalAPI>) {
-        let internal_rpc_api = create_api_with_config(api_config).await;
+    ) -> (SocketAddr, Arc<InternalAPI>, BitcoindStopper) {
+        let (internal_rpc_api, bitcoind_stopper) = create_api_with_config(api_config).await;
         let cloned = internal_rpc_api.clone();
 
         let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
@@ -343,18 +361,19 @@ mod test_helpers {
                 .unwrap();
         });
 
-        (addr, cloned)
+        (addr, cloned, bitcoind_stopper)
     }
 
-    pub(crate) async fn run_tower_in_background() -> SocketAddr {
-        run_tower_in_background_with_config(ApiConfig::default())
-            .await
-            .0
+    pub(crate) async fn run_tower_in_background() -> (SocketAddr, BitcoindStopper) {
+        let (sock_addr, _, bitcoind_stopper) =
+            run_tower_in_background_with_config(ApiConfig::default()).await;
+
+        (sock_addr, bitcoind_stopper)
     }
 
-    pub(crate) async fn check_api_error<'a>(
-        endpoint: &str,
-        body: RequestBody<'a>,
+    pub(crate) async fn check_api_error(
+        endpoint: Endpoint,
+        body: RequestBody<'_>,
         server_addr: SocketAddr,
     ) -> (ApiError, StatusCode) {
         let grpc_conn = PublicTowerServicesClient::connect(format!(
@@ -366,15 +385,22 @@ mod test_helpers {
         .unwrap();
 
         let req = match body {
-            RequestBody::Json(j) => warp::test::request().method("POST").path(endpoint).json(&j),
-            RequestBody::DoNotJsonify(j) => {
-                warp::test::request().method("POST").path(endpoint).json(&j)
-            }
+            RequestBody::Json(j) => warp::test::request()
+                .method("POST")
+                .path(&endpoint.path())
+                .json(&j),
+            RequestBody::DoNotJsonify(j) => warp::test::request()
+                .method("POST")
+                .path(&endpoint.path())
+                .json(&j),
             RequestBody::Jsonify(j) => warp::test::request()
                 .method("POST")
-                .path(endpoint)
+                .path(&endpoint.path())
                 .json(&serde_json::from_str::<Value>(j).unwrap()),
-            RequestBody::Body(b) => warp::test::request().method("POST").path(endpoint).body(b),
+            RequestBody::Body(b) => warp::test::request()
+                .method("POST")
+                .path(&endpoint.path())
+                .body(b),
         };
 
         let res = req.reply(&router(grpc_conn)).await;
@@ -385,7 +411,7 @@ mod test_helpers {
     }
 
     pub(crate) async fn request_to_api<B, T>(
-        endpoint: &str,
+        endpoint: Endpoint,
         body: B,
         server_addr: SocketAddr,
     ) -> Result<T, serde_json::Error>
@@ -403,7 +429,7 @@ mod test_helpers {
 
         let res = warp::test::request()
             .method("POST")
-            .path(endpoint)
+            .path(&endpoint.path())
             .json(&serde_json::json!(body))
             .reply(&router(grpc_conn))
             .await;
@@ -414,16 +440,16 @@ mod test_helpers {
 
 #[cfg(test)]
 mod tests_failures {
+    use super::test_helpers::{check_api_error, run_tower_in_background, RequestBody};
     use super::*;
 
-    use super::test_helpers::{check_api_error, run_tower_in_background, RequestBody};
-    use crate::test_utils::get_random_user_id;
+    use teos_common::test_utils::get_random_user_id;
 
     #[tokio::test]
     async fn test_no_json_request_body() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
         let (api_error, status) =
-            check_api_error("/register", RequestBody::Body(""), server_addr).await;
+            check_api_error(Endpoint::Register, RequestBody::Body(""), server_addr).await;
         assert!(api_error.error.contains("EOF while parsing"));
         assert_eq!(api_error.error_code, errors::INVALID_REQUEST_FORMAT);
         assert_eq!(status, StatusCode::BAD_REQUEST);
@@ -431,9 +457,13 @@ mod tests_failures {
 
     #[tokio::test]
     async fn test_wrong_json_request_body() {
-        let server_addr = run_tower_in_background().await;
-        let (api_error, status) =
-            check_api_error("/register", RequestBody::DoNotJsonify(""), server_addr).await;
+        let (server_addr, _s) = run_tower_in_background().await;
+        let (api_error, status) = check_api_error(
+            Endpoint::Register,
+            RequestBody::DoNotJsonify(""),
+            server_addr,
+        )
+        .await;
         assert!(api_error.error.contains("expected struct"));
         assert_eq!(api_error.error_code, errors::WRONG_FIELD_TYPE);
         assert_eq!(status, StatusCode::BAD_REQUEST);
@@ -441,9 +471,13 @@ mod tests_failures {
 
     #[tokio::test]
     async fn test_empty_json_request_body() {
-        let server_addr = run_tower_in_background().await;
-        let (api_error, status) =
-            check_api_error("/register", RequestBody::Jsonify(r#"{}"#), server_addr).await;
+        let (server_addr, _s) = run_tower_in_background().await;
+        let (api_error, status) = check_api_error(
+            Endpoint::Register,
+            RequestBody::Jsonify(r#"{}"#),
+            server_addr,
+        )
+        .await;
         assert!(api_error.error.contains("missing field"));
         assert_eq!(api_error.error_code, errors::MISSING_FIELD);
         assert_eq!(status, StatusCode::BAD_REQUEST);
@@ -451,9 +485,9 @@ mod tests_failures {
 
     #[tokio::test]
     async fn test_empty_field() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
         let (api_error, status) = check_api_error(
-            "/register",
+            Endpoint::Register,
             RequestBody::Jsonify(r#"{"user_id": ""}"#),
             server_addr,
         )
@@ -465,9 +499,9 @@ mod tests_failures {
 
     #[tokio::test]
     async fn test_wrong_field_hex_encoding_odd() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
         let (api_error, status) = check_api_error(
-            "/register",
+            Endpoint::Register,
             RequestBody::Jsonify(r#"{"user_id": "a"}"#),
             server_addr,
         )
@@ -479,9 +513,9 @@ mod tests_failures {
 
     #[tokio::test]
     async fn test_wrong_hex_encoding_character() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
         let (api_error, status) =
-        check_api_error("/register",  
+        check_api_error(Endpoint::Register,
         RequestBody::Jsonify(r#"{"user_id": "022fa2900ed7fc07b4e8ca3ea081e846245b0497944644aa78ea0b994ac22074dZ"}"#),
         server_addr
     ).await;
@@ -493,9 +527,9 @@ mod tests_failures {
 
     #[tokio::test]
     async fn test_wrong_field_size() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
         let (api_error, status) = check_api_error(
-            "/register",
+            Endpoint::Register,
             RequestBody::Jsonify(r#"{"user_id": "aa"}"#),
             server_addr,
         )
@@ -508,9 +542,9 @@ mod tests_failures {
 
     #[tokio::test]
     async fn test_wrong_field_type() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
         let (api_error, status) = check_api_error(
-            "/register",
+            Endpoint::Register,
             RequestBody::DoNotJsonify(r#"{"user_id": 1}"#),
             server_addr,
         )
@@ -523,9 +557,9 @@ mod tests_failures {
     #[tokio::test]
     async fn test_request_missing_field() {
         // We'll use a different endpoint here since we need a json object with more than one field
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
         let (api_error, status) = check_api_error(
-            "/add_appointment",
+            Endpoint::AddAppointment,
             RequestBody::Jsonify(r#"{"signature": "aa"}"#),
             server_addr,
         )
@@ -539,7 +573,7 @@ mod tests_failures {
 
     #[tokio::test]
     async fn test_empty_request_body() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
         let grpc_conn = PublicTowerServicesClient::connect(format!(
             "http://{}:{}",
             server_addr.ip(),
@@ -550,16 +584,16 @@ mod tests_failures {
 
         let res = warp::test::request()
             .method("POST")
-            .path("/register")
+            .path(&Endpoint::Register.path())
             .reply(&router(grpc_conn))
             .await;
 
-        assert_eq!(res.status(), StatusCode::LENGTH_REQUIRED)
+        assert_eq!(res.status(), StatusCode::LENGTH_REQUIRED);
     }
 
     #[tokio::test]
     async fn test_payload_too_large() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
         let grpc_conn = PublicTowerServicesClient::connect(format!(
             "http://{}:{}",
             server_addr.ip(),
@@ -570,17 +604,17 @@ mod tests_failures {
 
         let res = warp::test::request()
             .method("POST")
-            .path("/register")
+            .path(&Endpoint::Register.path())
             .json(&format!("{}{}", get_random_user_id(), get_random_user_id()))
             .reply(&router(grpc_conn))
             .await;
 
-        assert_eq!(res.status(), StatusCode::PAYLOAD_TOO_LARGE)
+        assert_eq!(res.status(), StatusCode::PAYLOAD_TOO_LARGE);
     }
 
     #[tokio::test]
     async fn test_wrong_endpoint() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
         let grpc_conn = PublicTowerServicesClient::connect(format!(
             "http://{}:{}",
             server_addr.ip(),
@@ -591,17 +625,16 @@ mod tests_failures {
 
         let res = warp::test::request()
             .method("POST")
-            .path("/")
             .json(&"")
             .reply(&router(grpc_conn))
             .await;
 
-        assert_eq!(res.status(), StatusCode::NOT_FOUND)
+        assert_eq!(res.status(), StatusCode::METHOD_NOT_ALLOWED);
     }
 
     #[tokio::test]
     async fn test_wrong_method() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
         let grpc_conn = PublicTowerServicesClient::connect(format!(
             "http://{}:{}",
             server_addr.ip(),
@@ -611,54 +644,57 @@ mod tests_failures {
         .unwrap();
 
         let res = warp::test::request()
-            .path("/")
             .json(&"")
             .reply(&router(grpc_conn))
             .await;
 
-        assert_eq!(res.status(), StatusCode::METHOD_NOT_ALLOWED)
+        assert_eq!(res.status(), StatusCode::METHOD_NOT_ALLOWED);
     }
 }
 
 #[cfg(test)]
 mod tests_methods {
-    use super::*;
-
     use super::test_helpers::{
         check_api_error, request_to_api, run_tower_in_background,
         run_tower_in_background_with_config, RequestBody,
     };
-    use crate::extended_appointment::UUID;
+    use super::*;
+
+    use crate::responder::{ConfirmationStatus, TransactionTracker};
     use crate::test_utils::{
-        generate_dummy_appointment, get_random_user_id, ApiConfig, DURATION, SLOTS,
+        generate_dummy_appointment, get_random_tx, ApiConfig, DURATION, SLOTS,
     };
+    use crate::watcher::Breach;
+
+    use teos_common::test_utils::get_random_user_id;
     use teos_common::{cryptography, UserId};
 
     #[tokio::test]
     async fn test_register() {
-        let server_addr = run_tower_in_background().await;
-        let response = request_to_api::<msgs::RegisterRequest, msgs::RegisterResponse>(
-            "/register",
-            msgs::RegisterRequest {
-                user_id: get_random_user_id().serialize(),
-            },
-            server_addr,
-        )
-        .await;
-        assert!(matches!(response, Ok(msgs::RegisterResponse { .. })));
+        let (server_addr, _s) = run_tower_in_background().await;
+        let response =
+            request_to_api::<common_msgs::RegisterRequest, common_msgs::RegisterResponse>(
+                Endpoint::Register,
+                common_msgs::RegisterRequest {
+                    user_id: get_random_user_id().to_vec(),
+                },
+                server_addr,
+            )
+            .await;
+        assert!(matches!(response, Ok(common_msgs::RegisterResponse { .. })));
     }
 
     #[tokio::test]
     async fn test_register_max_slots() {
-        let (server_addr, _) =
+        let (server_addr, _, _s) =
             run_tower_in_background_with_config(ApiConfig::new(u32::MAX, DURATION)).await;
         let user_id = get_random_user_id();
 
         // Register once, this should go trough and set slots to the limit
-        request_to_api::<msgs::RegisterRequest, msgs::RegisterResponse>(
-            "/register",
-            msgs::RegisterRequest {
-                user_id: user_id.serialize(),
+        request_to_api::<common_msgs::RegisterRequest, common_msgs::RegisterResponse>(
+            Endpoint::Register,
+            common_msgs::RegisterRequest {
+                user_id: user_id.to_vec(),
             },
             server_addr,
         )
@@ -668,9 +704,9 @@ mod tests_methods {
         // Register again to get additional slots, this should fail
         assert_eq!(
             check_api_error(
-                "/register",
-                RequestBody::Json(serde_json::json!(msgs::RegisterRequest {
-                    user_id: user_id.serialize(),
+                Endpoint::Register,
+                RequestBody::Json(serde_json::json!(common_msgs::RegisterRequest {
+                    user_id: user_id.to_vec(),
                 })),
                 server_addr,
             )
@@ -687,7 +723,7 @@ mod tests_methods {
 
     #[tokio::test]
     async fn test_register_service_unavailable() {
-        let (server_addr, _) = run_tower_in_background_with_config(
+        let (server_addr, _, _s) = run_tower_in_background_with_config(
             ApiConfig::new(SLOTS, DURATION).bitcoind_unreachable(),
         )
         .await;
@@ -696,9 +732,9 @@ mod tests_methods {
         // Register with bitcoind down
         assert_eq!(
             check_api_error(
-                "/register",
-                RequestBody::Json(serde_json::json!(msgs::RegisterRequest {
-                    user_id: user_id.serialize(),
+                Endpoint::Register,
+                RequestBody::Json(serde_json::json!(common_msgs::RegisterRequest {
+                    user_id: user_id.to_vec(),
                 })),
                 server_addr,
             )
@@ -715,13 +751,13 @@ mod tests_methods {
 
     #[tokio::test]
     async fn test_add_appointment() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
 
         // Register first
         let (user_sk, user_pk) = cryptography::get_random_keypair();
-        request_to_api::<msgs::RegisterRequest, msgs::RegisterResponse>(
-            "/register",
-            msgs::RegisterRequest {
+        request_to_api::<common_msgs::RegisterRequest, common_msgs::RegisterResponse>(
+            Endpoint::Register,
+            common_msgs::RegisterRequest {
                 user_id: user_pk.serialize().to_vec(),
             },
             server_addr,
@@ -731,11 +767,14 @@ mod tests_methods {
 
         // Then try to add an appointment
         let appointment = generate_dummy_appointment(None).inner;
-        let signature = cryptography::sign(&appointment.serialize(), &user_sk).unwrap();
+        let signature = cryptography::sign(&appointment.to_vec(), &user_sk);
 
-        let response = request_to_api::<msgs::AddAppointmentRequest, msgs::AddAppointmentResponse>(
-            "/add_appointment",
-            msgs::AddAppointmentRequest {
+        let response = request_to_api::<
+            common_msgs::AddAppointmentRequest,
+            common_msgs::AddAppointmentResponse,
+        >(
+            Endpoint::AddAppointment,
+            common_msgs::AddAppointmentRequest {
                 appointment: Some(appointment.into()),
                 signature,
             },
@@ -743,20 +782,23 @@ mod tests_methods {
         )
         .await;
 
-        assert!(matches!(response, Ok(msgs::AddAppointmentResponse { .. })));
+        assert!(matches!(
+            response,
+            Ok(common_msgs::AddAppointmentResponse { .. })
+        ));
     }
 
     #[tokio::test]
     async fn test_add_appointment_non_registered() {
-        let server_addr = run_tower_in_background().await;
-        let (user_sk, _) = cryptography::get_random_keypair();
+        let (server_addr, _s) = run_tower_in_background().await;
+        let (user_sk, _s) = cryptography::get_random_keypair();
         let appointment = generate_dummy_appointment(None).inner;
-        let signature = cryptography::sign(&appointment.serialize(), &user_sk).unwrap();
+        let signature = cryptography::sign(&appointment.to_vec(), &user_sk);
 
         assert_eq!(
             check_api_error(
-                "/add_appointment",
-                RequestBody::Json(serde_json::json!(msgs::AddAppointmentRequest {
+                Endpoint::AddAppointment,
+                RequestBody::Json(serde_json::json!(common_msgs::AddAppointmentRequest {
                     appointment: Some(appointment.into()),
                     signature,
                 })),
@@ -776,14 +818,14 @@ mod tests_methods {
     #[tokio::test]
     async fn test_add_appointment_already_triggered() {
         // Get the InternalAPI so we can mess with the inner state
-        let (server_addr, internal_api) =
+        let (server_addr, internal_api, _s) =
             run_tower_in_background_with_config(ApiConfig::new(u32::MAX, DURATION)).await;
 
         // Register
         let (user_sk, user_pk) = cryptography::get_random_keypair();
-        request_to_api::<msgs::RegisterRequest, msgs::RegisterResponse>(
-            "/register",
-            msgs::RegisterRequest {
+        request_to_api::<common_msgs::RegisterRequest, common_msgs::RegisterResponse>(
+            Endpoint::Register,
+            common_msgs::RegisterRequest {
                 user_id: user_pk.serialize().to_vec(),
             },
             server_addr,
@@ -791,18 +833,24 @@ mod tests_methods {
         .await
         .unwrap();
 
-        // Add the appointment to the Responder so it counts as triggered
-        let appointment = generate_dummy_appointment(None).inner;
-        let signature = cryptography::sign(&appointment.serialize(), &user_sk).unwrap();
+        // Add the appointment to the Responder as a tracker so it counts as triggered
+        let dispute_tx = get_random_tx();
+        let tracker = TransactionTracker::new(
+            Breach::new(dispute_tx.clone(), get_random_tx()),
+            UserId(user_pk),
+            ConfirmationStatus::ConfirmedIn(100),
+        );
         internal_api
             .get_watcher()
-            .add_random_tracker_to_responder(UUID::new(appointment.locator, UserId(user_pk)));
+            .add_dummy_tracker_to_responder(&tracker);
 
         // Try to add it via the http API
+        let appointment = generate_dummy_appointment(Some(&dispute_tx.compute_txid())).inner;
+        let signature = cryptography::sign(&appointment.to_vec(), &user_sk);
         assert_eq!(
             check_api_error(
-                "/add_appointment",
-                RequestBody::Json(serde_json::json!(msgs::AddAppointmentRequest {
+                Endpoint::AddAppointment,
+                RequestBody::Json(serde_json::json!(common_msgs::AddAppointmentRequest {
                     appointment: Some(appointment.into()),
                     signature,
                 })),
@@ -821,18 +869,18 @@ mod tests_methods {
 
     #[tokio::test]
     async fn test_add_appointment_service_unavailable() {
-        let (server_addr, _) = run_tower_in_background_with_config(
+        let (server_addr, _, _s) = run_tower_in_background_with_config(
             ApiConfig::new(SLOTS, DURATION).bitcoind_unreachable(),
         )
         .await;
         let (user_sk, _) = cryptography::get_random_keypair();
         let appointment = generate_dummy_appointment(None).inner;
-        let signature = cryptography::sign(&appointment.serialize(), &user_sk).unwrap();
+        let signature = cryptography::sign(&appointment.to_vec(), &user_sk);
 
         assert_eq!(
             check_api_error(
-                "/add_appointment",
-                RequestBody::Json(serde_json::json!(msgs::AddAppointmentRequest {
+                Endpoint::AddAppointment,
+                RequestBody::Json(serde_json::json!(common_msgs::AddAppointmentRequest {
                     appointment: Some(appointment.into()),
                     signature,
                 })),
@@ -851,13 +899,13 @@ mod tests_methods {
 
     #[tokio::test]
     async fn test_get_appointment() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
 
         // Register first
         let (user_sk, user_pk) = cryptography::get_random_keypair();
-        request_to_api::<msgs::RegisterRequest, msgs::RegisterResponse>(
-            "/register",
-            msgs::RegisterRequest {
+        request_to_api::<common_msgs::RegisterRequest, common_msgs::RegisterResponse>(
+            Endpoint::Register,
+            common_msgs::RegisterRequest {
                 user_id: user_pk.serialize().to_vec(),
             },
             server_addr,
@@ -867,11 +915,11 @@ mod tests_methods {
 
         // Add an appointment
         let appointment = generate_dummy_appointment(None).inner;
-        let signature = cryptography::sign(&appointment.serialize(), &user_sk).unwrap();
+        let signature = cryptography::sign(&appointment.to_vec(), &user_sk);
 
-        request_to_api::<msgs::AddAppointmentRequest, msgs::AddAppointmentResponse>(
-            "/add_appointment",
-            msgs::AddAppointmentRequest {
+        request_to_api::<common_msgs::AddAppointmentRequest, common_msgs::AddAppointmentResponse>(
+            Endpoint::AddAppointment,
+            common_msgs::AddAppointmentRequest {
                 appointment: Some(appointment.clone().into()),
                 signature,
             },
@@ -881,26 +929,31 @@ mod tests_methods {
         .unwrap();
 
         // Get it back
-        let response = request_to_api::<msgs::GetAppointmentRequest, msgs::GetAppointmentResponse>(
-            "/get_appointment",
-            msgs::GetAppointmentRequest {
-                locator: appointment.locator.serialize(),
+        let response = request_to_api::<
+            common_msgs::GetAppointmentRequest,
+            common_msgs::GetAppointmentResponse,
+        >(
+            Endpoint::GetAppointment,
+            common_msgs::GetAppointmentRequest {
+                locator: appointment.locator.to_vec(),
                 signature: cryptography::sign(
                     format!("get appointment {}", appointment.locator).as_bytes(),
                     &user_sk,
-                )
-                .unwrap(),
+                ),
             },
             server_addr,
         )
         .await;
 
-        assert!(matches!(response, Ok(msgs::GetAppointmentResponse { .. })));
+        assert!(matches!(
+            response,
+            Ok(common_msgs::GetAppointmentResponse { .. })
+        ));
     }
 
     #[tokio::test]
     async fn test_get_appointment_non_registered() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
 
         // User is not registered
         let (user_sk, _) = cryptography::get_random_keypair();
@@ -909,14 +962,13 @@ mod tests_methods {
 
         assert_eq!(
             check_api_error(
-                "/get_appointment",
-                RequestBody::Json(serde_json::json!(msgs::GetAppointmentRequest {
-                    locator: appointment.locator.serialize(),
+                Endpoint::GetAppointment,
+                RequestBody::Json(serde_json::json!(common_msgs::GetAppointmentRequest {
+                    locator: appointment.locator.to_vec(),
                     signature: cryptography::sign(
                         format!("get appointment {}", appointment.locator).as_bytes(),
                         &user_sk,
                     )
-                    .unwrap()
                 })),
                 server_addr,
             )
@@ -933,13 +985,13 @@ mod tests_methods {
 
     #[tokio::test]
     async fn test_get_appointment_not_found() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
 
         // Register first
         let (user_sk, user_pk) = cryptography::get_random_keypair();
-        request_to_api::<msgs::RegisterRequest, msgs::RegisterResponse>(
-            "/register",
-            msgs::RegisterRequest {
+        request_to_api::<common_msgs::RegisterRequest, common_msgs::RegisterResponse>(
+            Endpoint::Register,
+            common_msgs::RegisterRequest {
                 user_id: user_pk.serialize().to_vec(),
             },
             server_addr,
@@ -952,14 +1004,13 @@ mod tests_methods {
 
         assert_eq!(
             check_api_error(
-                "/get_appointment",
-                RequestBody::Json(serde_json::json!(msgs::GetAppointmentRequest {
-                    locator: appointment.locator.serialize(),
+                Endpoint::GetAppointment,
+                RequestBody::Json(serde_json::json!(common_msgs::GetAppointmentRequest {
+                    locator: appointment.locator.to_vec(),
                     signature: cryptography::sign(
                         format!("get appointment {}", appointment.locator).as_bytes(),
                         &user_sk,
                     )
-                    .unwrap()
                 })),
                 server_addr,
             )
@@ -976,7 +1027,7 @@ mod tests_methods {
 
     #[tokio::test]
     async fn test_get_appointment_service_unavailable() {
-        let (server_addr, _) = run_tower_in_background_with_config(
+        let (server_addr, _, _s) = run_tower_in_background_with_config(
             ApiConfig::new(SLOTS, DURATION).bitcoind_unreachable(),
         )
         .await;
@@ -987,14 +1038,13 @@ mod tests_methods {
 
         assert_eq!(
             check_api_error(
-                "/get_appointment",
-                RequestBody::Json(serde_json::json!(msgs::GetAppointmentRequest {
-                    locator: appointment.locator.serialize(),
+                Endpoint::GetAppointment,
+                RequestBody::Json(serde_json::json!(common_msgs::GetAppointmentRequest {
+                    locator: appointment.locator.to_vec(),
                     signature: cryptography::sign(
                         format!("get appointment {}", appointment.locator).as_bytes(),
                         &user_sk,
                     )
-                    .unwrap()
                 })),
                 server_addr,
             )
@@ -1011,13 +1061,13 @@ mod tests_methods {
 
     #[tokio::test]
     async fn test_get_subscription_info() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
 
         // Register first
         let (user_sk, user_pk) = cryptography::get_random_keypair();
-        request_to_api::<msgs::RegisterRequest, msgs::RegisterResponse>(
-            "/register",
-            msgs::RegisterRequest {
+        request_to_api::<common_msgs::RegisterRequest, common_msgs::RegisterResponse>(
+            Endpoint::Register,
+            common_msgs::RegisterRequest {
                 user_id: user_pk.serialize().to_vec(),
             },
             server_addr,
@@ -1026,36 +1076,36 @@ mod tests_methods {
         .unwrap();
 
         // Get the subscription info
-        let response =
-            request_to_api::<msgs::GetSubscriptionInfoRequest, msgs::GetSubscriptionInfoResponse>(
-                "/get_subscription_info",
-                msgs::GetSubscriptionInfoRequest {
-                    signature: cryptography::sign("get subscription info".as_bytes(), &user_sk)
-                        .unwrap(),
-                },
-                server_addr,
-            )
-            .await;
+        let response = request_to_api::<
+            common_msgs::GetSubscriptionInfoRequest,
+            common_msgs::GetSubscriptionInfoResponse,
+        >(
+            Endpoint::GetSubscriptionInfo,
+            common_msgs::GetSubscriptionInfoRequest {
+                signature: cryptography::sign("get subscription info".as_bytes(), &user_sk),
+            },
+            server_addr,
+        )
+        .await;
 
         assert!(matches!(
             response,
-            Ok(msgs::GetSubscriptionInfoResponse { .. })
+            Ok(common_msgs::GetSubscriptionInfoResponse { .. })
         ));
     }
 
     #[tokio::test]
     async fn test_get_subscription_info_non_registered() {
-        let server_addr = run_tower_in_background().await;
+        let (server_addr, _s) = run_tower_in_background().await;
 
         // User is not registered
         let (user_sk, _) = cryptography::get_random_keypair();
 
         assert_eq!(
             check_api_error(
-                "/get_subscription_info",
-                RequestBody::Json(serde_json::json!(msgs::GetSubscriptionInfoRequest {
+                Endpoint::GetSubscriptionInfo,
+                RequestBody::Json(serde_json::json!(common_msgs::GetSubscriptionInfoRequest {
                     signature: cryptography::sign("get subscription info".as_bytes(), &user_sk)
-                        .unwrap(),
                 })),
                 server_addr,
             )
@@ -1073,17 +1123,16 @@ mod tests_methods {
     #[tokio::test]
     async fn test_get_subscription_info_service_unavailable() {
         let (user_sk, _) = cryptography::get_random_keypair();
-        let (server_addr, _) = run_tower_in_background_with_config(
+        let (server_addr, _, _s) = run_tower_in_background_with_config(
             ApiConfig::new(SLOTS, DURATION).bitcoind_unreachable(),
         )
         .await;
 
         assert_eq!(
             check_api_error(
-                "/get_subscription_info",
-                RequestBody::Json(serde_json::json!(msgs::GetSubscriptionInfoRequest {
+                Endpoint::GetSubscriptionInfo,
+                RequestBody::Json(serde_json::json!(common_msgs::GetSubscriptionInfoRequest {
                     signature: cryptography::sign("get subscription info".as_bytes(), &user_sk)
-                        .unwrap(),
                 })),
                 server_addr,
             )

teos/src/api/mod.rs

@@ -1,43 +1,4 @@
 pub mod http;
 pub mod internal;
-
-pub mod serde_status {
-    use serde::de::{self, Deserializer};
-    use serde::ser::Serializer;
-    use std::str::FromStr;
-
-    use teos_common::appointment::AppointmentStatus;
-
-    pub fn serialize<S>(status: &i32, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        serializer.serialize_str(&AppointmentStatus::from(*status).to_string())
-    }
-
-    pub fn deserialize<'de, D>(deserializer: D) -> Result<i32, D::Error>
-    where
-        D: Deserializer<'de>,
-    {
-        struct StatusVisitor;
-
-        impl<'de> de::Visitor<'de> for StatusVisitor {
-            type Value = i32;
-
-            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-                formatter.write_str("a string containing the status")
-            }
-
-            fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
-            where
-                E: de::Error,
-            {
-                let status = AppointmentStatus::from_str(v)
-                    .map_err(|_| E::custom("given status is unknown"))?;
-                Ok(status as i32)
-            }
-        }
-
-        deserializer.deserialize_any(StatusVisitor)
-    }
-}
+pub mod serde;
+pub mod tor;

teos/src/api/serde.rs

@@ -0,0 +1,62 @@
+use crate::protos as msgs;
+
+use teos_common::net::AddressType;
+
+impl msgs::NetworkAddress {
+    pub fn from_ipv4(address: String, port: u16) -> Self {
+        Self {
+            address_type: AddressType::IpV4 as i32,
+            address,
+            port: port as u32,
+        }
+    }
+
+    pub fn from_torv3(address: String, port: u16) -> Self {
+        Self {
+            address_type: AddressType::TorV3 as i32,
+            address,
+            port: port as u32,
+        }
+    }
+}
+
+pub mod serde_address_type {
+    use serde::de::{self, Deserializer};
+    use serde::Serializer;
+    use std::str::FromStr;
+
+    use super::AddressType;
+
+    pub fn serialize<S>(status: &i32, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_str(&AddressType::from(*status).to_string())
+    }
+
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<i32, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        struct StatusVisitor;
+
+        impl<'de> de::Visitor<'de> for StatusVisitor {
+            type Value = i32;
+
+            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+                formatter.write_str("a string containing the address type")
+            }
+
+            fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+            where
+                E: de::Error,
+            {
+                let status = AddressType::from_str(v)
+                    .map_err(|_| E::custom("given address type is unknown"))?;
+                Ok(status as i32)
+            }
+        }
+
+        deserializer.deserialize_any(StatusVisitor)
+    }
+}

teos/src/api/tor.rs

@@ -0,0 +1,210 @@
+use std::convert::TryInto;
+use std::io::{Error, ErrorKind};
+use std::net::SocketAddr;
+use std::path::PathBuf;
+
+use tokio::fs;
+use tokio::net::TcpStream;
+use torut::control::UnauthenticatedConn;
+use torut::onion::TorSecretKeyV3;
+use triggered::{Listener, Trigger};
+
+pub struct TorAPI {
+    sk: TorSecretKeyV3,
+    api_endpoint: SocketAddr,
+    onion_port: u16,
+    tor_control_port: u16,
+}
+
+impl TorAPI {
+    pub async fn new(
+        api_endpoint: SocketAddr,
+        onion_port: u16,
+        tor_control_port: u16,
+        path: PathBuf,
+    ) -> Self {
+        let key = if let Some(key) = TorAPI::load_sk(path.clone()).await {
+            key
+        } else {
+            log::info!("Generating fresh Tor secret key");
+            let key = TorSecretKeyV3::generate();
+            TorAPI::store_sk(&key, path).await;
+            key
+        };
+
+        Self {
+            sk: key,
+            api_endpoint,
+            onion_port,
+            tor_control_port,
+        }
+    }
+
+    pub fn get_onion_address(&self) -> String {
+        self.sk.public().get_onion_address().to_string()
+    }
+
+    /// Loads a Tor key from disk (if found).
+    async fn load_sk(path: PathBuf) -> Option<TorSecretKeyV3> {
+        log::info!("Loading Tor secret key from disk");
+        let key = fs::read(path.join("onion_v3_sk"))
+            .await
+            .map_err(|e| log::warn!("Tor secret key cannot be loaded. {e}"))
+            .ok()?;
+        let key: [u8; 64] = key
+            .try_into()
+            .map_err(|_| log::error!("Cannot convert loaded data into Tor secret key"))
+            .ok()?;
+
+        Some(TorSecretKeyV3::from(key))
+    }
+
+    /// Stores a Tor key to disk.
+    async fn store_sk(key: &TorSecretKeyV3, path: PathBuf) {
+        if let Err(e) = fs::write(path.join("onion_v3_sk"), key.as_bytes()).await {
+            log::error!("Cannot store Tor secret key. {e}");
+        }
+    }
+
+    /// Tries to connect to the Tor control port
+    async fn connect_tor_cp(&self) -> Result<TcpStream, Error> {
+        let sock = TcpStream::connect(format!("127.0.0.1:{}", self.tor_control_port))
+            .await
+            .map_err(|_| {
+                Error::new(
+                    ErrorKind::ConnectionRefused,
+                    "failed to connect to Tor control port",
+                )
+            })?;
+        Ok(sock)
+    }
+
+    /// Expose an onion service that re-directs to the public api.
+    pub async fn expose_onion_service(
+        &self,
+        service_ready: Trigger,
+        shutdown_signal_tor: Listener,
+    ) -> Result<(), Error> {
+        let stream = self
+            .connect_tor_cp()
+            .await
+            .map_err(|e| Error::new(ErrorKind::ConnectionRefused, e))?;
+
+        let mut unauth_conn = UnauthenticatedConn::new(stream);
+
+        let pre_auth = unauth_conn
+            .load_protocol_info()
+            .await
+            .map_err(|e| Error::new(ErrorKind::ConnectionRefused, e))?;
+
+        let auth_data = pre_auth
+            .make_auth_data()?
+            .expect("failed to make auth data");
+
+        unauth_conn.authenticate(&auth_data).await.map_err(|_| {
+            Error::new(
+                ErrorKind::PermissionDenied,
+                "failed to authenticate with Tor",
+            )
+        })?;
+
+        let mut auth_conn = unauth_conn.into_authenticated().await;
+
+        auth_conn.set_async_event_handler(Some(|_| async move { Ok(()) }));
+
+        auth_conn
+            .add_onion_v3(
+                &self.sk,
+                false,
+                false,
+                false,
+                None,
+                &mut [(self.onion_port, self.api_endpoint)].iter(),
+            )
+            .await
+            .map_err(|e| {
+                Error::new(
+                    ErrorKind::Other,
+                    format!("failed to create onion hidden service: {e}"),
+                )
+            })?;
+
+        log::info!(
+            "Onion service: {}:{}",
+            self.get_onion_address(),
+            self.onion_port
+        );
+        service_ready.trigger();
+        shutdown_signal_tor.await;
+
+        auth_conn
+            .del_onion(
+                &self
+                    .sk
+                    .public()
+                    .get_onion_address()
+                    .get_address_without_dot_onion(),
+            )
+            .await
+            .unwrap();
+        Ok(())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tempdir::TempDir;
+
+    use teos_common::test_utils::get_random_user_id;
+
+    #[tokio::test]
+    async fn test_store_load_sk() {
+        let key = TorSecretKeyV3::generate();
+        let tmp_path = TempDir::new(&format!("data_dir_{}", get_random_user_id())).unwrap();
+
+        TorAPI::store_sk(&key, tmp_path.path().into()).await;
+        let loaded_key = TorAPI::load_sk(tmp_path.path().into()).await;
+
+        assert_eq!(key, loaded_key.unwrap())
+    }
+
+    #[tokio::test]
+    async fn test_load_sk_inexistent() {
+        let tmp_path = TempDir::new(&format!("data_dir_{}", get_random_user_id())).unwrap();
+        let loaded_key = TorAPI::load_sk(tmp_path.path().into()).await;
+
+        assert_eq!(loaded_key, None);
+    }
+
+    #[tokio::test]
+    async fn test_load_sk_wrong_format() {
+        let tmp_path = TempDir::new(&format!("data_dir_{}", get_random_user_id())).unwrap();
+        fs::write(tmp_path.path().join("onion_v3_sk"), "random stuff")
+            .await
+            .unwrap();
+        let loaded_key = TorAPI::load_sk(tmp_path.path().into()).await;
+
+        assert_eq!(loaded_key, None);
+    }
+
+    #[tokio::test]
+    async fn test_connect_tor_cp_fail() {
+        let wrong_cp = 9000;
+        let tmp_path = TempDir::new(&format!("data_dir_{}", get_random_user_id())).unwrap();
+        let tor_api = TorAPI::new(
+            "127.0.1.1:9814".parse().unwrap(),
+            9814,
+            wrong_cp,
+            tmp_path.path().into(),
+        )
+        .await;
+
+        match tor_api.connect_tor_cp().await {
+            Ok(_) => {}
+            Err(e) => {
+                assert_eq!("failed to connect to Tor control port", e.to_string())
+            }
+        }
+    }
+}

teos/src/bitcoin_cli.rs

@@ -9,17 +9,19 @@
  * at your option.
 */
 
+use base64::{engine::general_purpose::URL_SAFE as BASE64, Engine};
+use std::convert::TryInto;
+use std::io::{Error, ErrorKind};
 use std::sync::Arc;
 use tokio::sync::Mutex;
 
-use bitcoin::base64;
 use bitcoin::hash_types::{BlockHash, Txid};
-use bitcoin::hashes::hex::ToHex;
-use bitcoin::{Block, Transaction};
+use bitcoin::Transaction;
+use bitcoincore_rpc::{Auth, RawTx};
 use lightning::util::ser::Writeable;
-use lightning_block_sync::http::HttpEndpoint;
+use lightning_block_sync::http::{HttpEndpoint, JsonResponse};
 use lightning_block_sync::rpc::RpcClient;
-use lightning_block_sync::{AsyncBlockSourceResult, BlockHeaderData, BlockSource};
+use lightning_block_sync::{AsyncBlockSourceResult, BlockData, BlockHeaderData, BlockSource};
 
 /// A simple implementation of a bitcoind client (`bitcoin-cli`) with the minimal functionality required by the tower.
 pub struct BitcoindClient<'a> {
@@ -30,39 +32,39 @@ pub struct BitcoindClient<'a> {
     /// The port to connect to.
     port: u16,
     /// The RPC user `bitcoind` is configured with.
-    rpc_user: &'a str,
+    rpc_user: String,
     /// The RPC password for the given user.
-    rpc_password: &'a str,
+    rpc_password: String,
 }
 
 impl BlockSource for &BitcoindClient<'_> {
     /// Gets a block header given its hash.
     fn get_header<'a>(
-        &'a mut self,
+        &'a self,
         header_hash: &'a BlockHash,
         height_hint: Option<u32>,
     ) -> AsyncBlockSourceResult<'a, BlockHeaderData> {
         Box::pin(async move {
-            let mut rpc = self.bitcoind_rpc_client.lock().await;
+            let rpc = self.bitcoind_rpc_client.lock().await;
             rpc.get_header(header_hash, height_hint).await
         })
     }
 
     /// Gets a block given its hash.
     fn get_block<'a>(
-        &'a mut self,
+        &'a self,
         header_hash: &'a BlockHash,
-    ) -> AsyncBlockSourceResult<'a, Block> {
+    ) -> AsyncBlockSourceResult<'a, BlockData> {
         Box::pin(async move {
-            let mut rpc = self.bitcoind_rpc_client.lock().await;
+            let rpc = self.bitcoind_rpc_client.lock().await;
             rpc.get_block(header_hash).await
         })
     }
 
     /// Get the best block known by our node.
-    fn get_best_block(&mut self) -> AsyncBlockSourceResult<(BlockHash, Option<u32>)> {
+    fn get_best_block(&self) -> AsyncBlockSourceResult<(BlockHash, Option<u32>)> {
         Box::pin(async move {
-            let mut rpc = self.bitcoind_rpc_client.lock().await;
+            let rpc = self.bitcoind_rpc_client.lock().await;
             rpc.get_best_block().await
         })
     }
@@ -75,12 +77,34 @@ impl<'a> BitcoindClient<'a> {
     pub async fn new(
         host: &'a str,
         port: u16,
-        rpc_user: &'a str,
-        rpc_password: &'a str,
+        auth: Auth,
+        teos_network: &'a str,
     ) -> std::io::Result<BitcoindClient<'a>> {
         let http_endpoint = HttpEndpoint::for_host(host.to_owned()).with_port(port);
-        let rpc_credentials = base64::encode(&format!("{}:{}", rpc_user, rpc_password));
-        let bitcoind_rpc_client = RpcClient::new(&rpc_credentials, http_endpoint)?;
+        let (rpc_user, rpc_password) = {
+            let (user, pass) = auth.get_user_pass().map_err(|e| {
+                Error::new(
+                    ErrorKind::InvalidInput,
+                    format!("Cannot read cookie file. {}", e),
+                )
+            })?;
+            if user.is_none() {
+                Err(Error::new(
+                    ErrorKind::InvalidInput,
+                    "Empty btc_rpc_user parsed from rpc_cookie".to_string(),
+                ))
+            } else if pass.is_none() {
+                Err(Error::new(
+                    ErrorKind::InvalidInput,
+                    "Empty btc_rpc_password parsed from rpc_cookie",
+                ))
+            } else {
+                Ok((user.unwrap(), pass.unwrap()))
+            }
+        }?;
+
+        let rpc_credentials = BASE64.encode(format!("{}:{}", rpc_user, rpc_password));
+        let bitcoind_rpc_client = RpcClient::new(&rpc_credentials, http_endpoint);
 
         let client = Self {
             bitcoind_rpc_client: Arc::new(Mutex::new(bitcoind_rpc_client)),
@@ -90,17 +114,25 @@ impl<'a> BitcoindClient<'a> {
             rpc_password,
         };
 
-        // Test that bitcoind is reachable
-        match client.get_best_block_hash_and_height().await {
-            Ok(_) => Ok(client),
-            Err(e) => Err(e),
+        // Test that bitcoind is reachable.
+        let btc_network = client.get_chain().await?;
+
+        // Assert teos runs on the same chain/network as bitcoind.
+        if btc_network != teos_network {
+            Err(Error::new(
+                ErrorKind::InvalidInput,
+                format!("bitcoind is running on {btc_network} but teosd is set to run on {teos_network}"),
+            ))
+        } else {
+            Ok(client)
         }
     }
 
     /// Gets a fresh RPC client.
-    pub fn get_new_rpc_client(&self) -> std::io::Result<RpcClient> {
+    pub fn get_new_rpc_client(&self) -> RpcClient {
         let http_endpoint = HttpEndpoint::for_host(self.host.to_owned()).with_port(self.port);
-        let rpc_credentials = base64::encode(&format!("{}:{}", self.rpc_user, self.rpc_password));
+        let rpc_credentials = BASE64.encode(format!("{}:{}", self.rpc_user, self.rpc_password));
+
         RpcClient::new(&rpc_credentials, http_endpoint)
     }
 
@@ -108,26 +140,46 @@ impl<'a> BitcoindClient<'a> {
     pub async fn get_best_block_hash_and_height(
         &self,
     ) -> Result<(BlockHash, Option<u32>), std::io::Error> {
-        let mut rpc = self.bitcoind_rpc_client.lock().await;
+        let rpc = self.bitcoind_rpc_client.lock().await;
         rpc.call_method::<(BlockHash, Option<u32>)>("getblockchaininfo", &[])
             .await
     }
 
     /// Sends a transaction to the network.
     pub async fn send_raw_transaction(&self, raw_tx: &Transaction) -> Result<Txid, std::io::Error> {
-        let mut rpc = self.bitcoind_rpc_client.lock().await;
+        let rpc = self.bitcoind_rpc_client.lock().await;
 
-        let raw_tx_json = serde_json::json!(raw_tx.encode().to_hex());
+        let raw_tx_json = serde_json::json!(raw_tx.encode().raw_hex());
         rpc.call_method::<Txid>("sendrawtransaction", &[raw_tx_json])
             .await
     }
 
     /// Gets a transaction given its id.
     pub async fn get_raw_transaction(&self, txid: &Txid) -> Result<Transaction, std::io::Error> {
-        let mut rpc = self.bitcoind_rpc_client.lock().await;
+        let rpc = self.bitcoind_rpc_client.lock().await;
 
-        let txid_hex = serde_json::json!(txid.encode().to_hex());
+        let txid_hex = serde_json::json!(txid.encode().raw_hex());
         rpc.call_method::<Transaction>("getrawtransaction", &[txid_hex])
             .await
     }
+
+    /// Gets bitcoind's network.
+    pub async fn get_chain(&self) -> std::io::Result<String> {
+        // A wrapper type to extract "chain" key from getblockchaininfo JsonResponse.
+        struct BtcNetwork(String);
+        impl TryInto<BtcNetwork> for JsonResponse {
+            type Error = std::io::Error;
+            fn try_into(self) -> std::io::Result<BtcNetwork> {
+                Ok(BtcNetwork(self.0["chain"].as_str().unwrap().to_string()))
+            }
+        }
+
+        // Ask the RPC client for the network bitcoind is running on.
+        let rpc = self.bitcoind_rpc_client.lock().await;
+        let btc_network = rpc
+            .call_method::<BtcNetwork>("getblockchaininfo", &[])
+            .await?;
+
+        Ok(btc_network.0)
+    }
 }

teos/src/carrier.rs

@@ -6,7 +6,7 @@ use std::sync::{Arc, Condvar, Mutex};
 use crate::responder::ConfirmationStatus;
 use crate::{errors, rpc_errors};
 
-use bitcoin::{BlockHash, Transaction, Txid};
+use bitcoin::{Transaction, Txid};
 use bitcoincore_rpc::{
     jsonrpc::error::Error::Rpc as RpcError, jsonrpc::error::Error::Transport as TransportError,
     Client as BitcoindClient, Error::JsonRpc as JsonRpcError, RpcApi,
@@ -22,7 +22,7 @@ pub struct Carrier {
     /// A map of receipts already issued by the [Carrier].
     /// Used to prevent potentially re-sending the same transaction over and over.
     issued_receipts: HashMap<Txid, ConfirmationStatus>,
-    /// The last known block header.
+    /// The last known block height.
     block_height: u32,
 }
 
@@ -41,6 +41,11 @@ impl Carrier {
         }
     }
 
+    /// The last known block height.
+    pub(crate) fn block_height(&self) -> u32 {
+        self.block_height
+    }
+
     /// Clears the receipts cached by the [Carrier]. Should be called periodically to prevent it from
     /// growing unbounded.
     pub(crate) fn clear_receipts(&mut self) {
@@ -75,49 +80,49 @@ impl Carrier {
     pub(crate) fn send_transaction(&mut self, tx: &Transaction) -> ConfirmationStatus {
         self.hang_until_bitcoind_reachable();
 
-        if let Some(receipt) = self.issued_receipts.get(&tx.txid()) {
-            log::info!("Transaction already sent: {}", tx.txid());
+        if let Some(receipt) = self.issued_receipts.get(&tx.compute_txid()) {
+            log::info!("Transaction already sent: {}", tx.compute_txid());
             return *receipt;
         }
 
-        log::info!("Pushing transaction to the network: {}", tx.txid());
+        log::info!("Pushing transaction to the network: {}", tx.compute_txid());
         let receipt = match self.bitcoin_cli.send_raw_transaction(tx) {
             Ok(_) => {
                 // Here the transaction could, potentially, have been in mempool before the current height.
                 // This shouldn't really matter though.
-                log::info!("Transaction successfully delivered: {}", tx.txid());
+                log::info!("Transaction successfully delivered: {}", tx.compute_txid());
                 ConfirmationStatus::InMempoolSince(self.block_height)
             }
             Err(JsonRpcError(RpcError(rpcerr))) => match rpcerr.code {
                 // Since we're pushing a raw transaction to the network we can face several rejections
                 rpc_errors::RPC_VERIFY_REJECTED => {
-                    log::error!("Transaction couldn't be broadcast. {:?}", rpcerr);
+                    log::error!("Transaction couldn't be broadcast. {rpcerr:?}");
                     ConfirmationStatus::Rejected(rpc_errors::RPC_VERIFY_REJECTED)
                 }
                 rpc_errors::RPC_VERIFY_ERROR => {
-                    log::error!("Transaction couldn't be broadcast. {:?}", rpcerr);
+                    log::error!("Transaction couldn't be broadcast. {rpcerr:?}");
                     ConfirmationStatus::Rejected(rpc_errors::RPC_VERIFY_ERROR)
                 }
                 rpc_errors::RPC_VERIFY_ALREADY_IN_CHAIN => {
                     log::info!(
-                        "Transaction is already in the blockchain: {}. Getting confirmation count",
-                        tx.txid()
+                        "Transaction was confirmed long ago, not keeping track of it: {}",
+                        tx.compute_txid()
                     );
 
-                    ConfirmationStatus::ConfirmedIn(self.get_tx_height(&tx.txid()).unwrap())
+                    // Given we are not using txindex, if a transaction bounces we cannot get its confirmation count. However, [send_transaction] is guarded by
+                    // checking whether the transaction id can be found in the [Responder]'s [TxIndex], meaning that if the transaction bounces it was confirmed long
+                    // ago (> IRREVOCABLY_RESOLVED), so we don't need to worry about it.
+                    ConfirmationStatus::IrrevocablyResolved
                 }
                 rpc_errors::RPC_DESERIALIZATION_ERROR => {
                     // Adding this here just for completeness. We should never end up here. The Carrier only sends txs handed by the Responder,
                     // who receives them from the Watcher, who checks that the tx can be properly deserialized.
-                    log::info!("Transaction cannot be deserialized: {}", tx.txid());
+                    log::info!("Transaction cannot be deserialized: {}", tx.compute_txid());
                     ConfirmationStatus::Rejected(rpc_errors::RPC_DESERIALIZATION_ERROR)
                 }
                 _ => {
                     // If something else happens (unlikely but possible) log it so we can treat it in future releases.
-                    log::error!(
-                        "Unexpected rpc error when calling sendrawtransaction: {:?}",
-                        rpcerr
-                    );
+                    log::error!("Unexpected rpc error when calling sendrawtransaction: {rpcerr:?}");
                     ConfirmationStatus::Rejected(errors::UNKNOWN_JSON_RPC_EXCEPTION)
                 }
             },
@@ -129,87 +134,48 @@ impl Carrier {
             }
             Err(e) => {
                 // TODO: This may need finer catching.
-                log::error!("Unexpected error when calling sendrawtransaction: {:?}", e);
+                log::error!("Unexpected error when calling sendrawtransaction: {e:?}");
                 ConfirmationStatus::Rejected(errors::UNKNOWN_JSON_RPC_EXCEPTION)
             }
         };
 
-        self.issued_receipts.insert(tx.txid(), receipt);
+        self.issued_receipts.insert(tx.compute_txid(), receipt);
 
         receipt
     }
 
-    /// Gets the block height at where a given [Transaction] was confirmed at (if any).
-    fn get_tx_height(&self, txid: &Txid) -> Option<u32> {
-        if let Some(block_hash) = self.get_block_hash_for_tx(txid) {
-            self.get_block_height(&block_hash)
-        } else {
-            None
-        }
-    }
-
-    /// Queries the height of a given [Block](bitcoin::Block). Returns it if the block can be found. Returns [None] otherwise.
-    fn get_block_height(&self, block_hash: &BlockHash) -> Option<u32> {
-        self.hang_until_bitcoind_reachable();
-
-        match self.bitcoin_cli.get_block_header_info(block_hash) {
-            Ok(header_data) => Some(header_data.height as u32),
-            Err(JsonRpcError(RpcError(rpcerr))) => match rpcerr.code {
-                rpc_errors::RPC_INVALID_ADDRESS_OR_KEY => {
-                    log::info!("Block not found: {}", block_hash);
-                    None
-                }
-                e => {
-                    log::error!("Unexpected error code when calling getblockheader: {}", e);
-                    None
-                }
-            },
-            Err(JsonRpcError(TransportError(_))) => {
-                // Connection refused, bitcoind is down.
-                log::error!("Connection lost with bitcoind, retrying request when possible");
-                self.flag_bitcoind_unreachable();
-                self.get_block_height(block_hash)
-            }
-            // TODO: This may need finer catching.
-            Err(e) => {
-                log::error!("Unexpected JSONRPCError when calling getblockheader: {}", e);
-                None
-            }
-        }
-    }
-
-    /// Gets the block hash where a given [Transaction] was confirmed at (if any).
-    pub(crate) fn get_block_hash_for_tx(&self, txid: &Txid) -> Option<BlockHash> {
+    /// Checks whether a given transaction can be found in the mempool.
+    ///
+    /// This uses `getrawtransaction` under the hood and, therefore, its behavior depends on whether `txindex` is enabled in bitcoind.
+    /// If `txindex` is disabled (default), it will only pull data from the mempool. Otherwise, it will also pull data from the transaction
+    /// index. Hence, we need to check whether the returned struct has any of the block related datum set (such as `blockhash`).
+    pub(crate) fn in_mempool(&self, txid: &Txid) -> bool {
         self.hang_until_bitcoind_reachable();
 
         match self.bitcoin_cli.get_raw_transaction_info(txid, None) {
-            Ok(tx_data) => tx_data.blockhash,
+            Ok(tx) => tx.blockhash.is_none(),
             Err(JsonRpcError(RpcError(rpcerr))) => match rpcerr.code {
                 rpc_errors::RPC_INVALID_ADDRESS_OR_KEY => {
-                    log::info!("Transaction not found in mempool nor blockchain: {}", txid);
-                    None
+                    log::info!("Transaction not found in mempool: {txid}");
+                    false
                 }
                 e => {
-                    log::error!(
-                        "Unexpected error code when calling getrawtransaction: {}",
-                        e
-                    );
-                    None
+                    // DISCUSS: This could result in a silent error with unknown consequences
+                    log::error!("Unexpected error code when calling getrawtransaction: {e}");
+                    false
                 }
             },
             Err(JsonRpcError(TransportError(_))) => {
                 // Connection refused, bitcoind is down.
                 log::error!("Connection lost with bitcoind, retrying request when possible");
                 self.flag_bitcoind_unreachable();
-                self.get_block_hash_for_tx(txid)
+                self.in_mempool(txid)
             }
             // TODO: This may need finer catching.
             Err(e) => {
-                log::error!(
-                    "Unexpected JSONRPCError when calling getrawtransaction: {}",
-                    e
-                );
-                None
+                // DISCUSS: This could result in a silent error with unknown consequences
+                log::error!("Unexpected JSONRPCError when calling getrawtransaction: {e}");
+                false
             }
         }
     }
@@ -218,13 +184,13 @@ impl Carrier {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use std::str::FromStr;
     use std::thread;
 
-    use crate::test_utils::{
-        get_random_tx, start_server, BitcoindMock, MockOptions, START_HEIGHT, TX_HEX,
-    };
+    use crate::test_utils::{get_random_tx, start_server, BitcoindMock, MockOptions, START_HEIGHT};
+    use teos_common::test_utils::{TXID_HEX, TX_HEX};
 
-    use bitcoin::consensus::deserialize;
+    use bitcoin::consensus;
     use bitcoin::hashes::hex::FromHex;
     use bitcoincore_rpc::Auth;
 
@@ -242,18 +208,17 @@ mod tests {
 
     #[test]
     fn test_clear_receipts() {
-        let bitcoind_mock = BitcoindMock::new(MockOptions::empty());
+        let bitcoind_mock = BitcoindMock::new(MockOptions::default());
         let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
         let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
         let start_height = START_HEIGHT as u32;
-        start_server(bitcoind_mock);
 
         let mut carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
 
         // Lets add some dummy data into the cache
         for i in 0..10 {
             carrier.issued_receipts.insert(
-                get_random_tx().txid(),
+                get_random_tx().compute_txid(),
                 ConfirmationStatus::ConfirmedIn(start_height - i),
             );
         }
@@ -266,20 +231,38 @@ mod tests {
 
     #[test]
     fn test_send_transaction_ok() {
-        let bitcoind_mock = BitcoindMock::new(MockOptions::empty());
+        let bitcoind_mock = BitcoindMock::new(MockOptions::default());
         let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
         let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
         let start_height = START_HEIGHT as u32;
-        start_server(bitcoind_mock);
+        start_server(bitcoind_mock.server);
 
         let mut carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
-        let tx = deserialize::<Transaction>(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
+        let tx = consensus::deserialize(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
         let r = carrier.send_transaction(&tx);
 
         assert_eq!(r, ConfirmationStatus::InMempoolSince(start_height));
 
         // Check the receipt is on the cache
-        assert_eq!(carrier.issued_receipts.get(&tx.txid()).unwrap(), &r);
+        assert_eq!(carrier.issued_receipts.get(&tx.compute_txid()).unwrap(), &r);
+    }
+
+    #[test]
+    fn test_send_transaction_ok_already_in_mempool() {
+        let bitcoind_mock = BitcoindMock::new(MockOptions::in_mempool());
+        let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
+        let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
+        let start_height = START_HEIGHT as u32;
+        start_server(bitcoind_mock.server);
+
+        let mut carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
+        let tx = consensus::deserialize(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
+        let r = carrier.send_transaction(&tx);
+
+        assert_eq!(r, ConfirmationStatus::InMempoolSince(start_height));
+
+        // Check the receipt is on the cache
+        assert_eq!(carrier.issued_receipts.get(&tx.compute_txid()).unwrap(), &r);
     }
 
     #[test]
@@ -290,10 +273,10 @@ mod tests {
         let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
         let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
         let start_height = START_HEIGHT as u32;
-        start_server(bitcoind_mock);
+        start_server(bitcoind_mock.server);
 
         let mut carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
-        let tx = deserialize::<Transaction>(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
+        let tx = consensus::deserialize(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
         let r = carrier.send_transaction(&tx);
 
         assert_eq!(
@@ -302,7 +285,7 @@ mod tests {
         );
 
         // Check the receipt is on the cache
-        assert_eq!(carrier.issued_receipts.get(&tx.txid()).unwrap(), &r);
+        assert_eq!(carrier.issued_receipts.get(&tx.compute_txid()).unwrap(), &r);
     }
 
     #[test]
@@ -312,10 +295,10 @@ mod tests {
         let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
         let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
         let start_height = START_HEIGHT as u32;
-        start_server(bitcoind_mock);
+        start_server(bitcoind_mock.server);
 
         let mut carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
-        let tx = deserialize::<Transaction>(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
+        let tx = consensus::deserialize(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
         let r = carrier.send_transaction(&tx);
 
         assert_eq!(
@@ -324,29 +307,27 @@ mod tests {
         );
 
         // Check the receipt is on the cache
-        assert_eq!(carrier.issued_receipts.get(&tx.txid()).unwrap(), &r);
+        assert_eq!(carrier.issued_receipts.get(&tx.compute_txid()).unwrap(), &r);
     }
 
     #[test]
     fn test_send_transaction_verify_already_in_chain() {
-        let bitcoind_mock = BitcoindMock::new(MockOptions::new(
+        let bitcoind_mock = BitcoindMock::new(MockOptions::with_error(
             rpc_errors::RPC_VERIFY_ALREADY_IN_CHAIN as i64,
-            BlockHash::default(),
-            START_HEIGHT,
         ));
         let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
         let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
         let start_height = START_HEIGHT as u32;
-        start_server(bitcoind_mock);
+        start_server(bitcoind_mock.server);
 
         let mut carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
-        let tx = deserialize::<Transaction>(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
+        let tx = consensus::deserialize(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
         let r = carrier.send_transaction(&tx);
 
-        assert_eq!(r, ConfirmationStatus::ConfirmedIn(start_height));
+        assert_eq!(r, ConfirmationStatus::IrrevocablyResolved);
 
         // Check the receipt is on the cache
-        assert_eq!(carrier.issued_receipts.get(&tx.txid()).unwrap(), &r);
+        assert_eq!(carrier.issued_receipts.get(&tx.compute_txid()).unwrap(), &r);
     }
 
     #[test]
@@ -356,10 +337,10 @@ mod tests {
         let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
         let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
         let start_height = START_HEIGHT as u32;
-        start_server(bitcoind_mock);
+        start_server(bitcoind_mock.server);
 
         let mut carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
-        let tx = deserialize::<Transaction>(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
+        let tx = consensus::deserialize(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
         let r = carrier.send_transaction(&tx);
 
         assert_eq!(
@@ -368,19 +349,19 @@ mod tests {
         );
 
         // Check the receipt is on the cache
-        assert_eq!(carrier.issued_receipts.get(&tx.txid()).unwrap(), &r);
+        assert_eq!(carrier.issued_receipts.get(&tx.compute_txid()).unwrap(), &r);
     }
 
     #[test]
     fn test_send_transaction_connection_error() {
         // Try to connect to an offline bitcoind.
-        let bitcoind_mock = BitcoindMock::new(MockOptions::empty());
+        let bitcoind_mock = BitcoindMock::new(MockOptions::default());
         let bitcoind_reachable = Arc::new((Mutex::new(false), Condvar::new()));
         let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
         let start_height = START_HEIGHT as u32;
         let mut carrier = Carrier::new(bitcoin_cli, bitcoind_reachable.clone(), start_height);
 
-        let tx = deserialize::<Transaction>(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
+        let tx = consensus::deserialize(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
         let delay = std::time::Duration::new(3, 0);
 
         thread::spawn(move || {
@@ -401,91 +382,86 @@ mod tests {
     }
 
     #[test]
-    fn test_get_tx_height_ok() {
-        let target_height = 21;
+    fn test_in_mempool() {
+        let bitcoind_mock = BitcoindMock::new(MockOptions::in_mempool());
+        let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
+        let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
+        let start_height = START_HEIGHT as u32;
+        start_server(bitcoind_mock.server);
+
+        let carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
+        let txid = Txid::from_str(TXID_HEX).unwrap();
+        assert!(carrier.in_mempool(&txid));
+    }
+
+    #[test]
+    fn test_not_in_mempool() {
+        let bitcoind_mock = BitcoindMock::new(MockOptions::default());
+        let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
+        let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
+        let start_height = START_HEIGHT as u32;
+        start_server(bitcoind_mock.server);
+
+        let carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
+        let txid = Txid::from_str(TXID_HEX).unwrap();
+        assert!(!carrier.in_mempool(&txid));
+    }
+
+    #[test]
+    fn test_not_in_mempool_via_error() {
+        let bitcoind_mock = BitcoindMock::new(MockOptions::with_error(
+            rpc_errors::RPC_INVALID_ADDRESS_OR_KEY as i64,
+        ));
+        let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
+        let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
+        let start_height = START_HEIGHT as u32;
+        start_server(bitcoind_mock.server);
+
+        let carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
+        let txid = Txid::from_str(TXID_HEX).unwrap();
+        assert!(!carrier.in_mempool(&txid));
+    }
+
+    #[test]
+    fn test_in_mempool_unexpected_error() {
         let bitcoind_mock =
-            BitcoindMock::new(MockOptions::with_block(BlockHash::default(), target_height));
+            BitcoindMock::new(MockOptions::with_error(rpc_errors::RPC_MISC_ERROR as i64));
         let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
         let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
         let start_height = START_HEIGHT as u32;
-        start_server(bitcoind_mock);
+        start_server(bitcoind_mock.server);
 
         let carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
-        let tx = deserialize::<Transaction>(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
+        let txid = Txid::from_str(TXID_HEX).unwrap();
+        assert!(!carrier.in_mempool(&txid));
+    }
+
+    #[test]
+    fn test_in_mempool_connection_error() {
+        // Try to connect to an offline bitcoind.
+        let bitcoind_mock = BitcoindMock::new(MockOptions::default());
+        let bitcoind_reachable = Arc::new((Mutex::new(false), Condvar::new()));
+        let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
+        let start_height = START_HEIGHT as u32;
+        let carrier = Carrier::new(bitcoin_cli, bitcoind_reachable.clone(), start_height);
+
+        let txid = Txid::from_str(TXID_HEX).unwrap();
+        let delay = std::time::Duration::new(3, 0);
+
+        thread::spawn(move || {
+            thread::sleep(delay);
+            let (reachable, notifier) = &*bitcoind_reachable;
+            *reachable.lock().unwrap() = true;
+            notifier.notify_all();
+        });
+
+        let before = std::time::Instant::now();
+        carrier.in_mempool(&txid);
+
+        // Check the request has hanged for ~delay
         assert_eq!(
-            carrier.get_tx_height(&tx.txid()),
-            Some(target_height as u32)
+            (std::time::Instant::now() - before).as_secs(),
+            delay.as_secs()
         );
     }
-
-    #[test]
-    fn test_get_tx_height_not_found() {
-        // Hee we are not testing the case where the block hash is unknown (which will also return None). This is because we only
-        // learn block hashes from bitcoind, and once a block is known, it cannot disappear (ir can be disconnected, but not banish).
-        let bitcoind_mock = BitcoindMock::new(MockOptions::empty());
-        let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
-        let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
-        let start_height = START_HEIGHT as u32;
-        start_server(bitcoind_mock);
-
-        let carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
-        let tx = deserialize::<Transaction>(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
-        assert_eq!(carrier.get_tx_height(&tx.txid()), None);
-    }
-
-    #[test]
-    fn test_get_block_height_ok() {
-        let target_height = 21;
-        let block_hash = BlockHash::default();
-        let bitcoind_mock = BitcoindMock::new(MockOptions::with_block(block_hash, target_height));
-        let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
-        let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
-        let start_height = START_HEIGHT as u32;
-        start_server(bitcoind_mock);
-
-        let carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
-        assert_eq!(
-            carrier.get_block_height(&block_hash),
-            Some(target_height as u32)
-        );
-    }
-
-    #[test]
-    fn test_get_block_height_not_found() {
-        let bitcoind_mock = BitcoindMock::new(MockOptions::empty());
-        let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
-        let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
-        let start_height = START_HEIGHT as u32;
-        start_server(bitcoind_mock);
-
-        let carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
-        assert_eq!(carrier.get_block_height(&BlockHash::default()), None);
-    }
-
-    #[test]
-    fn test_get_block_hash_for_tx_ok() {
-        let block_hash = BlockHash::default();
-        let bitcoind_mock = BitcoindMock::new(MockOptions::with_block(block_hash, 21));
-        let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
-        let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
-        let start_height = START_HEIGHT as u32;
-        start_server(bitcoind_mock);
-
-        let tx = deserialize::<Transaction>(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
-        let carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
-        assert_eq!(carrier.get_block_hash_for_tx(&tx.txid()), Some(block_hash));
-    }
-
-    #[test]
-    fn test_get_block_hash_for_tx_not_found() {
-        let bitcoind_mock = BitcoindMock::new(MockOptions::empty());
-        let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
-        let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
-        let start_height = START_HEIGHT as u32;
-        start_server(bitcoind_mock);
-
-        let tx = deserialize::<Transaction>(&Vec::from_hex(TX_HEX).unwrap()).unwrap();
-        let carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, start_height);
-        assert_eq!(carrier.get_block_hash_for_tx(&tx.txid()), None);
-    }
 }

teos/src/chain_monitor.rs

@@ -26,7 +26,7 @@ where
 {
     /// A bitcoin client to poll best tips from.
     spv_client: SpvClient<'a, P, C, L>,
-    /// The lat known block header by the [ChainMonitor].
+    /// The last known block header by the [ChainMonitor].
     last_known_block_header: ValidatedBlockHeader,
     /// A [DBM] (database manager) instance. Used to persist block data into disk.
     dbm: Arc<Mutex<DBM>>,
@@ -100,7 +100,7 @@ where
             Err(e) => match e.kind() {
                 BlockSourceErrorKind::Persistent => {
                     // FIXME: This may need finer catching
-                    log::error!("Unexpected persistent error: {:?}", e);
+                    log::error!("Unexpected persistent error: {e:?}");
                 }
                 BlockSourceErrorKind::Transient => {
                     // Treating all transient as connection errors at least for now.
@@ -135,8 +135,8 @@ mod tests {
     use std::iter::FromIterator;
     use std::thread;
 
-    use bitcoin::network::constants::Network;
     use bitcoin::BlockHash;
+    use bitcoin::Network;
     use lightning_block_sync::{poll::ChainPoller, SpvClient, UnboundedCache};
 
     use crate::test_utils::{Blockchain, START_HEIGHT};
@@ -156,13 +156,18 @@ mod tests {
     }
 
     impl chain::Listen for DummyListener {
-        fn block_connected(&self, block: &bitcoin::Block, _: u32) {
+        fn filtered_block_connected(
+            &self,
+            header: &bitcoin::block::Header,
+            _: &chain::transaction::TransactionData,
+            _: u32,
+        ) {
             self.connected_blocks
                 .borrow_mut()
-                .insert(block.block_hash());
+                .insert(header.block_hash());
         }
 
-        fn block_disconnected(&self, header: &bitcoin::BlockHeader, _: u32) {
+        fn block_disconnected(&self, header: &bitcoin::block::Header, _: u32) {
             self.disconnected_blocks
                 .borrow_mut()
                 .insert(header.block_hash());
@@ -259,10 +264,7 @@ mod tests {
         // If a new (worse, just one) block gets mined, nothing gets connected nor disconnected
         cm.poll_best_tip().await;
         assert_eq!(cm.last_known_block_header, best_tip);
-        assert!(matches!(
-            cm.dbm.lock().unwrap().load_last_known_block(),
-            Err { .. }
-        ));
+        assert!(cm.dbm.lock().unwrap().load_last_known_block().is_none());
         assert!(listener.connected_blocks.borrow().is_empty());
         assert!(listener.disconnected_blocks.borrow().is_empty());
     }

teos/src/cli.rs

@@ -1,49 +1,97 @@
+use hex::FromHex;
 use serde_json::to_string_pretty as pretty_json;
-use std::fs;
 use std::str::FromStr;
 use structopt::StructOpt;
+use tokio::fs;
+use tonic::transport::{Certificate, Channel, ClientTlsConfig, Identity};
 use tonic::Request;
 
 use teos::cli_config::{Command, Config, Opt};
 use teos::config;
 use teos::protos as msgs;
 use teos::protos::private_tower_services_client::PrivateTowerServicesClient;
+use teos_common::appointment::Locator;
 use teos_common::UserId;
 
+/// Prints the cli error to standard error and exits the process
+fn handle_error<T: std::fmt::Display>(error: T) {
+    eprintln!("{}", error);
+    std::process::exit(1);
+}
+
 #[tokio::main]
 async fn main() {
     let opt = Opt::from_args();
     let path = config::data_dir_absolute_path(opt.data_dir.clone());
 
     // Create data dir if it does not exist
-    fs::create_dir_all(&path).unwrap_or_else(|e| {
-        eprintln!("Cannot create data dir: {:?}", e);
+    fs::create_dir_all(&path).await.unwrap_or_else(|e| {
+        eprintln!("Cannot create data dir: {e:?}");
         std::process::exit(1);
     });
 
     let command = opt.command.clone();
 
     // Load conf (from file or defaults) and patch it with the command line parameters received (if any)
-    let mut conf = config::from_file::<Config>(path.join("teos.toml"));
+    let mut conf = config::from_file::<Config>(&path.join("teos.toml"));
     conf.patch_with_options(opt);
 
-    // Create gRPC client and send request
-    let mut client =
-        PrivateTowerServicesClient::connect(format!("http://{}:{}", conf.rpc_bind, conf.rpc_port))
+    let key = fs::read(&path.join("client-key.pem"))
+        .await
+        .expect("unable to read client key from disk");
+    let certificate = fs::read(path.join("client.pem"))
+        .await
+        .expect("unable to read client cert from disk");
+    let ca_cert = Certificate::from_pem(
+        fs::read(path.join("ca.pem"))
             .await
-            .unwrap_or_else(|e| {
-                eprintln!("Cannot connect to the tower. Connection refused");
-                if conf.debug {
-                    eprintln!("{:?}", e);
-                }
-                std::process::exit(1);
-            });
+            .expect("unable to read ca cert from disk"),
+    );
+
+    let tls = ClientTlsConfig::new()
+        .domain_name("localhost")
+        .ca_certificate(ca_cert)
+        .identity(Identity::from_pem(certificate, key));
+
+    let channel = Channel::from_shared(format!("https://{}:{}", conf.rpc_bind, conf.rpc_port))
+        .expect("Cannot create channel from endpoint")
+        .tls_config(tls)
+        .unwrap_or_else(|e| {
+            eprintln!("Could not configure tls: {e:?}");
+            std::process::exit(1);
+        })
+        .connect()
+        .await
+        .unwrap_or_else(|_| {
+            eprintln!("Could not connect to tower. Is teosd running?");
+            std::process::exit(1);
+        });
+
+    let mut client = PrivateTowerServicesClient::new(channel);
 
     match command {
         Command::GetAllAppointments => {
             let appointments = client.get_all_appointments(Request::new(())).await.unwrap();
             println!("{}", pretty_json(&appointments.into_inner()).unwrap());
         }
+        Command::GetAppointments(appointments_data) => {
+            match Locator::from_hex(&appointments_data.locator) {
+                Ok(locator) => {
+                    match client
+                        .get_appointments(Request::new(msgs::GetAppointmentsRequest {
+                            locator: locator.to_vec(),
+                        }))
+                        .await
+                    {
+                        Ok(appointments) => {
+                            println!("{}", pretty_json(&appointments.into_inner()).unwrap())
+                        }
+                        Err(status) => handle_error(status.message()),
+                    }
+                }
+                Err(e) => handle_error(e),
+            };
+        }
         Command::GetTowerInfo => {
             let info = client.get_tower_info(Request::new(())).await.unwrap();
             println!("{}", pretty_json(&info.into_inner()).unwrap())
@@ -52,22 +100,22 @@ async fn main() {
             let users = client.get_users(Request::new(())).await.unwrap();
             println!("{}", pretty_json(&users.into_inner()).unwrap());
         }
-        Command::GetUser(data) => {
-            match UserId::from_str(&data.user_id) {
+        Command::GetUser(user) => {
+            match UserId::from_str(&user.user_id) {
                 Ok(user_id) => {
                     match client
                         .get_user(Request::new(msgs::GetUserRequest {
-                            user_id: user_id.serialize(),
+                            user_id: user_id.to_vec(),
                         }))
                         .await
                     {
                         Ok(response) => {
                             println!("{}", pretty_json(&response.into_inner()).unwrap())
                         }
-                        Err(status) => println!("{}", status.message()),
+                        Err(status) => handle_error(status.message()),
                     }
                 }
-                Err(e) => println!("{}", e),
+                Err(e) => handle_error(e),
             };
         }
         Command::Stop => {

teos/src/cli_config.rs

@@ -4,10 +4,12 @@ use serde::Deserialize;
 use structopt::StructOpt;
 
 #[derive(Debug, StructOpt, Clone)]
-#[structopt(rename_all = "snake_case")]
+#[structopt(rename_all = "lower_case")]
 pub enum Command {
     /// Gets information about all appointments stored in the tower
     GetAllAppointments,
+    /// Gets information about specific appointments stored in the tower using a locator
+    GetAppointments(GetAppointmentsData),
     /// Gets generic information about the tower, like tower id and aggregate data on users and appointments
     GetTowerInfo,
     /// Gets an array with the user ids of all the users registered to the tower
@@ -19,17 +21,23 @@ pub enum Command {
 }
 
 #[derive(Debug, StructOpt, Clone)]
-#[structopt(rename_all = "lowercase")]
+#[structopt(rename_all = "snake_case")]
 pub struct GetUserData {
     /// The user identifier (33-byte compressed public key).
     pub user_id: String,
 }
 
+#[derive(Debug, StructOpt, Clone)]
+pub struct GetAppointmentsData {
+    /// The locator of the appointments (16-byte hexadecimal string).
+    pub locator: String,
+}
+
 /// Holds all the command line options and commands.
 #[derive(StructOpt, Debug)]
 #[structopt(rename_all = "lowercase")]
 #[structopt(
-    version = "0.0.1",
+    version = env!("CARGO_PKG_VERSION"),
     about = "The Eye of Satoshi - CLI",
     name = "teos-cli"
 )]
@@ -46,10 +54,6 @@ pub struct Opt {
     #[structopt(long, default_value = "~/.teos")]
     pub data_dir: String,
 
-    /// Runs teos-cli in debug mode [default: false]
-    #[structopt(long)]
-    pub debug: bool,
-
     /// Command
     #[structopt(subcommand)]
     pub command: Command,
@@ -66,7 +70,6 @@ pub struct Opt {
 pub struct Config {
     pub rpc_bind: String,
     pub rpc_port: u16,
-    pub debug: bool,
 }
 
 impl Config {
@@ -78,8 +81,6 @@ impl Config {
         if options.rpc_port.is_some() {
             self.rpc_port = options.rpc_port.unwrap();
         }
-
-        self.debug |= options.debug;
     }
 }
 
@@ -94,7 +95,6 @@ impl Default for Config {
         Self {
             rpc_bind: "localhost".into(),
             rpc_port: 8814,
-            debug: false,
         }
     }
 }

teos/src/conf_template.toml

@@ -1,20 +1,26 @@
 # API
 api_bind = "127.0.0.1"
 api_port = 9814
+tor_control_port = 9051
+onion_hidden_service_port = 9814
+tor_support = false
 
 # RPC
 rpc_bind = "127.0.0.1"
 rpc_port = 8814
 
 # bitcoind
-btc_network = "bitcoin"
+btc_network = "mainnet"
 btc_rpc_user = "CSW"
+## Notice only user+password **OR** cookie is allowed as rpc auth, any other combination would be rejected
 btc_rpc_password = "NotSatoshi"
 btc_rpc_connect = "localhost"
-btc_rpc_port = 8442
+btc_rpc_cookie = "~/.bitcoin/.cookie"
+btc_rpc_port = 8332
 
 # Flags
 debug = false
+deps_debug = false
 overwrite_key = false
 
 # General

teos/src/config.rs

@@ -1,10 +1,7 @@
 //! Logic related to the tower configuration and command line parameter parsing.
 
-use bitcoin::network::constants::Network;
-use serde::Deserialize;
-use std;
+use serde::{Deserialize, Serialize};
 use std::path::PathBuf;
-use std::str::FromStr;
 use structopt::StructOpt;
 
 pub fn data_dir_absolute_path(data_dir: String) -> PathBuf {
@@ -19,24 +16,13 @@ pub fn data_dir_absolute_path(data_dir: String) -> PathBuf {
     }
 }
 
-pub fn from_file<T: Default + serde::de::DeserializeOwned>(path: PathBuf) -> T {
-    match std::fs::read(&path) {
-        Ok(file_content) => toml::from_slice::<T>(&file_content).map_or_else(
-            |e| {
-                println!("Couldn't parse config file: {}", e);
-                println!("Loading default configuration");
-                T::default()
-            },
-            |config| {
-                println!("Loading configuration from file");
-                config
-            },
-        ),
-        Err(e) => {
-            println!("Couldn't read config file: {}", e);
-            println!("Loading default configuration");
+pub fn from_file<T: Default + serde::de::DeserializeOwned>(path: &PathBuf) -> T {
+    match std::fs::read(path) {
+        Ok(file_content) => toml::from_slice::<T>(&file_content).unwrap_or_else(|e| {
+            eprintln!("Couldn't parse config file: {e}");
             T::default()
-        }
+        }),
+        Err(_) => T::default(),
     }
 }
 
@@ -52,10 +38,18 @@ impl std::fmt::Display for ConfigError {
 
 impl std::error::Error for ConfigError {}
 
+#[derive(PartialEq)]
+pub enum AuthMethod {
+    UserPass,
+    CookieFile,
+    Multiple,
+    Invalid,
+}
+
 /// Holds all the command line options.
 #[derive(StructOpt, Debug, Clone)]
 #[structopt(rename_all = "lowercase")]
-#[structopt(version = "0.0.1", about = "The Eye of Satoshi - Lightning watchtower")]
+#[structopt(version = env!("CARGO_PKG_VERSION"), about = "The Eye of Satoshi - Lightning watchtower")]
 pub struct Opt {
     /// Address teos HTTP(s) API will bind to [default: localhost]
     #[structopt(long)]
@@ -73,18 +67,22 @@ pub struct Opt {
     #[structopt(long)]
     pub rpc_port: Option<u16>,
 
-    /// Network bitcoind is connected to. Either bitcoin, testnet, signet or regtest [default: bitcoin]
+    /// Network bitcoind is connected to. Either mainnet, testnet, signet or regtest [default: mainnet]
     #[structopt(long)]
     pub btc_network: Option<String>,
 
-    /// bitcoind rpcuser [default: user]
+    /// bitcoind rpcuser
     #[structopt(long)]
     pub btc_rpc_user: Option<String>,
 
-    /// bitcoind rpcpassword [default: passwd]
+    /// bitcoind rpcpassword
     #[structopt(long)]
     pub btc_rpc_password: Option<String>,
 
+    /// bitcoind rpccookie
+    #[structopt(long)]
+    pub btc_rpc_cookie: Option<String>,
+
     /// bitcoind rpcconnect [default: localhost]
     #[structopt(long)]
     pub btc_rpc_connect: Option<String>,
@@ -101,9 +99,30 @@ pub struct Opt {
     #[structopt(long)]
     pub debug: bool,
 
+    /// Runs third party libs in debug mode
+    #[structopt(long)]
+    pub deps_debug: bool,
+
     /// Overwrites the tower secret key. THIS IS IRREVERSIBLE AND WILL CHANGE YOUR TOWER ID
     #[structopt(long)]
     pub overwrite_key: bool,
+
+    /// If set, creates a Tor endpoint to serve API data. This endpoint is additional to the clearnet HTTP API
+    #[structopt(long)]
+    pub tor_support: bool,
+
+    /// Forces the tower to run even if the underlying chain has gone too far out of sync. This can only happen
+    /// if the node is being run in pruned mode.
+    #[structopt(long)]
+    pub force_update: bool,
+
+    /// Tor control port [default: 9051]
+    #[structopt(long)]
+    pub tor_control_port: Option<u16>,
+
+    /// Port for the onion hidden service to listen on [default: 9814]
+    #[structopt(long)]
+    pub onion_hidden_service_port: Option<u16>,
 }
 
 /// Holds all configuration options.
@@ -112,7 +131,7 @@ pub struct Opt {
 /// - Defaults
 /// - Configuration file
 /// - Command line options
-#[derive(Debug, Deserialize, Clone, PartialEq, Eq)]
+#[derive(Debug, Deserialize, Serialize, Clone, PartialEq, Eq)]
 #[serde(default)]
 pub struct Config {
     // API
@@ -126,13 +145,16 @@ pub struct Config {
     // Bitcoind
     pub btc_network: String,
     pub btc_rpc_user: String,
+    pub btc_rpc_cookie: String,
     pub btc_rpc_password: String,
     pub btc_rpc_connect: String,
     pub btc_rpc_port: u16,
 
     // Flags
     pub debug: bool,
+    pub deps_debug: bool,
     pub overwrite_key: bool,
+    pub force_update: bool,
 
     // General
     pub subscription_slots: u32,
@@ -144,9 +166,32 @@ pub struct Config {
     // Internal API
     pub internal_api_bind: String,
     pub internal_api_port: u32,
+
+    // Tor
+    pub tor_support: bool,
+    pub tor_control_port: u16,
+    pub onion_hidden_service_port: u16,
 }
 
 impl Config {
+    /// The only combinations of valid authentication methods are:
+    ///     - User **AND** password
+    ///     - **OR** Cookie file
+    //
+    /// Any other combination will be rejected
+    pub fn get_auth_method(&self) -> AuthMethod {
+        match (
+            self.btc_rpc_user.is_empty(),
+            self.btc_rpc_password.is_empty(),
+            self.btc_rpc_cookie.is_empty(),
+        ) {
+            (false, false, true) => AuthMethod::UserPass,
+            (true, true, false) => AuthMethod::CookieFile,
+            (true, true, true) => AuthMethod::Invalid,
+            _ => AuthMethod::Multiple,
+        }
+    }
+
     /// Patches the configuration options with the command line options.
     pub fn patch_with_options(&mut self, options: Opt) {
         if options.api_bind.is_some() {
@@ -170,15 +215,27 @@ impl Config {
         if options.btc_rpc_password.is_some() {
             self.btc_rpc_password = options.btc_rpc_password.unwrap();
         }
+        if options.btc_rpc_cookie.is_some() {
+            self.btc_rpc_cookie = options.btc_rpc_cookie.unwrap();
+        }
         if options.btc_rpc_connect.is_some() {
             self.btc_rpc_connect = options.btc_rpc_connect.unwrap();
         }
         if options.btc_rpc_port.is_some() {
             self.btc_rpc_port = options.btc_rpc_port.unwrap();
         }
+        if options.tor_control_port.is_some() {
+            self.tor_control_port = options.tor_control_port.unwrap();
+        }
+        if options.onion_hidden_service_port.is_some() {
+            self.onion_hidden_service_port = options.onion_hidden_service_port.unwrap();
+        }
 
+        self.tor_support |= options.tor_support;
         self.debug |= options.debug;
+        self.deps_debug |= options.deps_debug;
         self.overwrite_key = options.overwrite_key;
+        self.force_update = options.force_update;
     }
 
     /// Verifies that [Config] is properly built.
@@ -190,30 +247,60 @@ impl Config {
     /// This will also assign the default `btc_rpc_port` depending on the network if it has not
     /// been overwritten at this point.
     pub fn verify(&mut self) -> Result<(), ConfigError> {
-        if self.btc_rpc_user == String::new() {
-            return Err(ConfigError("btc_rpc_user must be set".to_owned()));
-        }
-        if self.btc_rpc_password == String::new() {
-            return Err(ConfigError("btc_rpc_password must be set".to_owned()));
+        let auth_method = self.get_auth_method();
+        if auth_method == AuthMethod::Invalid {
+            return Err(ConfigError("No valid bitcoind auth provided. Set either both btc_rpc_user/btc_rpc_password or btc_rpc_cookie".to_owned()));
+        } else if auth_method == AuthMethod::Multiple {
+            return Err(ConfigError(
+                "Multiple bitcoind auth provided. Pick a single one (either btc_rpc_user/btc_rpc_password or btc_rpc_cookie)"
+                    .to_owned(),
+            ));
         }
 
-        match Network::from_str(&self.btc_network) {
-            Ok(network) => {
-                // Set the port to it's default (depending on the network) if it has not been
-                // overwritten at this point.
-                if self.btc_rpc_port == 0 {
-                    self.btc_rpc_port = match network {
-                        Network::Testnet => 18333,
-                        Network::Signet => 38333,
-                        Network::Regtest => 18443,
-                        _ => 8442,
+        // Normalize the network option to the ones used by bitcoind.
+        if ["mainnet", "testnet"].contains(&self.btc_network.as_str()) {
+            self.btc_network = self.btc_network.trim_end_matches("net").into();
+        }
+
+        let default_rpc_port = match self.btc_network.as_str() {
+            "main" => 8332,
+            "test" => 18332,
+            "regtest" => 18443,
+            "signet" => 38332,
+            _ => return Err(ConfigError(format!("btc_network not recognized. Expected {{mainnet, testnet, signet, regtest}}, received {}", self.btc_network)))
+        };
+
+        // Set the port to it's default (depending on the network) if it has not been
+        // overwritten at this point.
+        if self.btc_rpc_port == 0 {
+            self.btc_rpc_port = default_rpc_port;
+        }
+
+        Ok(())
+    }
+
+    /// Checks whether the config has been set with only with default values.
+    pub fn is_default(&self) -> bool {
+        self == &Config::default()
+    }
+
+    /// Logs non-default options.
+    pub fn log_non_default_options(&self) {
+        let json_default_config = serde_json::json!(&Config::default());
+        let json_config = serde_json::json!(&self);
+        let sensitive_args = ["btc_rpc_user", "btc_rpc_password"];
+
+        for (key, value) in json_config.as_object().unwrap().iter() {
+            if *value != json_default_config[key] {
+                log::info!(
+                    "Custom config arg: {}: {}",
+                    key,
+                    if sensitive_args.contains(&key.as_str()) {
+                        "****".to_owned()
+                    } else {
+                        value.to_string()
                     }
-                }
-                Ok(())
-            }
-            Err(_) => {
-                Err(ConfigError(format!("btc_network not recognized. Expected {{bitcoin, testnet, signet, regtest}}, received {}",
-                self.btc_network)))
+                );
             }
         }
     }
@@ -230,16 +317,22 @@ impl Default for Config {
         Self {
             api_bind: "127.0.0.1".into(),
             api_port: 9814,
+            tor_support: false,
+            tor_control_port: 9051,
+            onion_hidden_service_port: 9814,
             rpc_bind: "127.0.0.1".into(),
             rpc_port: 8814,
-            btc_network: "bitcoin".into(),
+            btc_network: "mainnet".into(),
             btc_rpc_user: String::new(),
             btc_rpc_password: String::new(),
+            btc_rpc_cookie: String::new(),
             btc_rpc_connect: "localhost".into(),
             btc_rpc_port: 0,
 
             debug: false,
+            deps_debug: false,
             overwrite_key: false,
+            force_update: false,
             subscription_slots: 10000,
             subscription_duration: 4320,
             expiry_delta: 6,
@@ -260,17 +353,23 @@ mod tests {
             Self {
                 api_bind: None,
                 api_port: None,
+                tor_support: false,
+                tor_control_port: None,
+                onion_hidden_service_port: None,
                 rpc_bind: None,
                 rpc_port: None,
                 btc_network: None,
                 btc_rpc_user: None,
                 btc_rpc_password: None,
+                btc_rpc_cookie: None,
                 btc_rpc_connect: None,
                 btc_rpc_port: None,
                 data_dir: String::from("~/.teos"),
 
                 debug: false,
+                deps_debug: false,
                 overwrite_key: false,
+                force_update: false,
             }
         }
     }
@@ -290,7 +389,7 @@ mod tests {
         assert_eq!(config.api_bind, expected_value);
 
         // Check the rest of fields are equal. The easiest is to just the field back and compare with a clone
-        config.api_bind = config_clone.api_bind.clone();
+        config.api_bind.clone_from(&config_clone.api_bind);
         assert_eq!(config, config_clone);
     }
 
@@ -299,7 +398,9 @@ mod tests {
         // Tests that the default configuration does not pass verification checks. This is on purpose so some fields are
         // required to be updated by the user.
         let mut config = Config::default();
-        assert!(matches!(config.verify(), Err(ConfigError { .. })));
+        assert!(
+            matches!(config.verify(), Err(ConfigError(e)) if e.contains("No valid bitcoind auth provided"))
+        );
     }
 
     #[test]
@@ -322,6 +423,20 @@ mod tests {
             btc_network: "wrong_network".to_owned(),
             ..Default::default()
         };
-        assert!(matches!(config.verify(), Err(ConfigError { .. })));
+        assert!(
+            matches!(config.verify(), Err(ConfigError(e)) if e.contains("btc_network not recognized"))
+        );
+    }
+
+    #[test]
+    fn test_config_verify_tor_set() {
+        let mut config = Config {
+            btc_rpc_user: "user".to_owned(),
+            btc_rpc_password: "password".to_owned(),
+            tor_support: true,
+            ..Default::default()
+        };
+
+        config.verify().unwrap()
     }
 }

teos/src/extended_appointment.rs

@@ -6,11 +6,11 @@ use std::fmt;
 
 use bitcoin::hashes::{ripemd160, Hash};
 
-use crate::protos as msgs;
 use teos_common::appointment::{Appointment, Locator};
 use teos_common::UserId;
 
 /// Unique identifier used to identify appointments.
+#[allow(clippy::upper_case_acronyms)]
 #[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)]
 pub(crate) struct UUID([u8; 20]);
 
@@ -21,18 +21,18 @@ impl UUID {
     /// when a user requests it without having to perform lookups based on the [Locator], and match what [UUID] belongs to what user (if any).
     /// Therefore, it provides a hard-to-forge id while reducing the tower lookups and the required data to be stored (no reverse maps).
     pub fn new(locator: Locator, user_id: UserId) -> Self {
-        let mut uuid_data = locator.serialize();
-        uuid_data.extend(&user_id.0.serialize());
-        UUID(ripemd160::Hash::hash(&uuid_data).into_inner())
+        let mut uuid_data = locator.to_vec();
+        uuid_data.extend(user_id.0.serialize());
+        UUID(ripemd160::Hash::hash(&uuid_data).to_byte_array())
     }
 
     /// Serializes the [UUID] returning its byte representation.
-    pub fn serialize(&self) -> Vec<u8> {
+    pub fn to_vec(self) -> Vec<u8> {
         self.0.to_vec()
     }
 
     /// Builds a [UUID] from its byte representation.
-    pub fn deserialize(data: &[u8]) -> Result<Self, TryFromSliceError> {
+    pub fn from_slice(data: &[u8]) -> Result<Self, TryFromSliceError> {
         data.try_into().map(Self)
     }
 }
@@ -46,8 +46,6 @@ impl std::fmt::Display for UUID {
 /// An extended version of the appointment hold by the tower.
 ///
 /// The [Appointment] is extended in terms of data, that is, it provides further information only relevant to the tower.
-/// Notice [ExtendedAppointment]s are not kept in memory but persisted on disk. The [Watcher](crate::watcher::Watcher)
-/// keeps [AppointmentSummary] instead.
 #[derive(Debug, Eq, PartialEq, Clone)]
 pub(crate) struct ExtendedAppointment {
     /// The underlying appointment extended by [ExtendedAppointment].
@@ -60,18 +58,6 @@ pub(crate) struct ExtendedAppointment {
     pub start_block: u32,
 }
 
-/// A summary of an appointment.
-///
-/// Contains the minimal amount of data the [Watcher](crate::watcher::Watcher) needs to keep in memory in order to
-/// watch for breaches.
-#[derive(Debug, Eq, PartialEq, Clone)]
-pub(crate) struct AppointmentSummary {
-    /// The [Appointment] locator.
-    pub locator: Locator,
-    /// The user this [Appointment] belongs to.
-    pub user_id: UserId,
-}
-
 impl ExtendedAppointment {
     /// Create a new [ExtendedAppointment].
     pub fn new(
@@ -103,52 +89,23 @@ impl ExtendedAppointment {
         self.inner.to_self_delay
     }
 
-    /// Computes the summary of the [ExtendedAppointment].
-    pub fn get_summary(&self) -> AppointmentSummary {
-        AppointmentSummary {
-            locator: self.locator(),
-            user_id: self.user_id,
-        }
+    pub fn uuid(&self) -> UUID {
+        UUID::new(self.inner.locator, self.user_id)
     }
 }
 
-impl From<Appointment> for msgs::Appointment {
-    fn from(a: Appointment) -> Self {
-        Self {
-            locator: a.locator.serialize(),
-            encrypted_blob: a.encrypted_blob.clone(),
-            to_self_delay: a.to_self_delay,
-        }
-    }
-}
-
-/// Computes the number of slots an appointment takes from a user subscription.
-///
-/// This is based on the [encrypted_blob](Appointment::encrypted_blob) size and the slot size that was defined by the [Gatekeeper](crate::gatekeeper::Gatekeeper).
-pub(crate) fn compute_appointment_slots(blob_size: usize, blob_max_size: usize) -> u32 {
-    (blob_size as f32 / blob_max_size as f32).ceil() as u32
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
 
-    use crate::test_utils::get_random_user_id;
-    use teos_common::appointment::Appointment;
-    use teos_common::cryptography::get_random_bytes;
+    use crate::test_utils::generate_uuid;
 
     #[test]
-    fn test_get_summary() {
-        let locator = Locator::deserialize(&get_random_bytes(16)).unwrap();
-        let user_id = get_random_user_id();
-        let signature = String::new();
-
-        let a = Appointment::new(locator, get_random_bytes(32), 42);
-        let e = ExtendedAppointment::new(a, user_id, signature, 21);
-
-        let s = e.get_summary();
-
-        assert_eq!(e.locator(), s.locator);
-        assert_eq!(e.user_id, s.user_id);
+    fn test_uuid_ser_deser() {
+        let original_uuid = generate_uuid();
+        assert_eq!(
+            UUID::from_slice(&original_uuid.to_vec()).unwrap(),
+            original_uuid
+        );
     }
 }

teos/src/gatekeeper.rs

@@ -1,51 +1,37 @@
 //! Logic related to the Gatekeeper, the component in charge of managing access to the tower resources.
 
-use std::collections::{HashMap, HashSet};
-use std::iter::FromIterator;
+use lightning::chain;
+use std::collections::HashMap;
 use std::sync::atomic::{AtomicU32, Ordering};
 use std::sync::{Arc, Mutex};
 
-use lightning::chain;
-
+use teos_common::appointment::{compute_appointment_slots, Locator};
 use teos_common::constants::ENCRYPTED_BLOB_MAX_SIZE;
 use teos_common::cryptography;
 use teos_common::receipts::RegistrationReceipt;
 use teos_common::UserId;
 
 use crate::dbm::DBM;
-use crate::extended_appointment::{compute_appointment_slots, ExtendedAppointment, UUID};
+use crate::extended_appointment::{ExtendedAppointment, UUID};
 
 /// Data regarding a user subscription with the tower.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub(crate) struct UserInfo {
     /// Number of appointment slots available for a given user.
     pub(crate) available_slots: u32,
-    /// Block height where the user subscription will expire.
+    /// Block height where the user subscription starts.
+    pub(crate) subscription_start: u32,
+    /// Block height where the user subscription expires.
     pub(crate) subscription_expiry: u32,
-    /// Map of appointment ids and the how many slots they take from the subscription.
-    pub(crate) appointments: HashMap<UUID, u32>,
 }
 
 impl UserInfo {
     /// Creates a new [UserInfo] instance.
-    pub fn new(available_slots: u32, subscription_expiry: u32) -> Self {
+    pub fn new(available_slots: u32, subscription_start: u32, subscription_expiry: u32) -> Self {
         UserInfo {
             available_slots,
+            subscription_start,
             subscription_expiry,
-            appointments: HashMap::new(),
-        }
-    }
-
-    /// Creates a new [UserInfo] instance with some associated appointments.
-    pub fn with_appointments(
-        available_slots: u32,
-        subscription_expiry: u32,
-        appointments: HashMap<UUID, u32>,
-    ) -> Self {
-        UserInfo {
-            available_slots,
-            subscription_expiry,
-            appointments,
         }
     }
 }
@@ -128,8 +114,9 @@ impl Gatekeeper {
     }
 
     /// Gets the data held by the tower about a given user.
-    pub(crate) fn get_user_info(&self, user_id: UserId) -> Option<UserInfo> {
-        self.registered_users.lock().unwrap().get(&user_id).cloned()
+    pub(crate) fn get_user_info(&self, user_id: UserId) -> Option<(UserInfo, Vec<Locator>)> {
+        let info = self.registered_users.lock().unwrap().get(&user_id).cloned();
+        info.map(|info| (info, self.dbm.lock().unwrap().load_user_locators(user_id)))
     }
 
     /// Authenticates a user.
@@ -169,7 +156,10 @@ impl Gatekeeper {
                     .available_slots
                     .checked_add(self.subscription_slots)
                     .ok_or(MaxSlotsReached)?;
-                user_info.subscription_expiry = block_count + self.subscription_duration;
+                user_info.subscription_expiry = user_info
+                    .subscription_expiry
+                    .checked_add(self.subscription_duration)
+                    .unwrap_or(u32::MAX);
                 self.dbm.lock().unwrap().update_user(user_id, user_info);
 
                 user_info
@@ -178,6 +168,7 @@ impl Gatekeeper {
             None => {
                 let user_info = UserInfo::new(
                     self.subscription_slots,
+                    block_count,
                     block_count + self.subscription_duration,
                 );
                 self.dbm
@@ -194,6 +185,7 @@ impl Gatekeeper {
         Ok(RegistrationReceipt::new(
             user_id,
             user_info.available_slots,
+            user_info.subscription_start,
             user_info.subscription_expiry,
         ))
     }
@@ -208,7 +200,13 @@ impl Gatekeeper {
         // For updates, the difference between the existing appointment size and the update is computed.
         let mut registered_users = self.registered_users.lock().unwrap();
         let user_info = registered_users.get_mut(&user_id).unwrap();
-        let used_slots = user_info.appointments.get(&uuid).map_or(0, |x| *x);
+        let used_blob_size = self
+            .dbm
+            .lock()
+            .unwrap()
+            .get_appointment_length(uuid)
+            .unwrap_or(0);
+        let used_slots = compute_appointment_slots(used_blob_size, ENCRYPTED_BLOB_MAX_SIZE);
 
         let required_slots =
             compute_appointment_slots(appointment.encrypted_blob().len(), ENCRYPTED_BLOB_MAX_SIZE);
@@ -217,7 +215,6 @@ impl Gatekeeper {
         if diff <= user_info.available_slots as i64 {
             // Filling / freeing slots depending on whether this is an update or not, and if it is bigger or smaller
             // than the old appointment
-            user_info.appointments.insert(uuid, required_slots);
             user_info.available_slots = (user_info.available_slots as i64 - diff) as u32;
 
             self.dbm.lock().unwrap().update_user(user_id, user_info);
@@ -247,56 +244,50 @@ impl Gatekeeper {
 
     /// Gets a map of outdated users. Outdated users are those whose subscription has expired and the renewal grace period
     /// has already passed ([expiry_delta](Self::expiry_delta)).
-    pub(crate) fn get_outdated_users(&self, block_height: u32) -> HashMap<UserId, HashSet<UUID>> {
-        let registered_users = self.registered_users.lock().unwrap().clone();
-        registered_users
-            .into_iter()
-            .filter(|(_, info)| block_height == info.subscription_expiry + self.expiry_delta)
-            .map(|(id, info)| (id, info.appointments.keys().cloned().collect()))
+    pub(crate) fn get_outdated_users(&self, block_height: u32) -> Vec<UserId> {
+        self.registered_users
+            .lock()
+            .unwrap()
+            .iter()
+            // NOTE: Ideally there won't be a user with `block_height > subscription_expiry + expiry_delta`, but
+            // this might happen if we skip a couple of block connections due to a force update.
+            .filter(|(_, info)| block_height >= info.subscription_expiry + self.expiry_delta)
+            .map(|(user_id, _)| *user_id)
             .collect()
     }
 
-    /// Gets a set of outdated user ids.
-    pub(crate) fn get_outdated_user_ids(&self, block_height: u32) -> HashSet<UserId> {
-        self.get_outdated_users(block_height)
-            .keys()
-            .cloned()
-            .collect()
-    }
-
-    /// Get a map of outdated appointments (from any user).
-    pub(crate) fn get_outdated_appointments(&self, block_height: u32) -> HashSet<UUID> {
-        HashSet::from_iter(
-            self.get_outdated_users(block_height)
-                .into_values()
-                .flatten(),
-        )
-    }
-
-    /// Deletes a collection of appointments from the users' subscriptions (from memory only)
-    /// and updates the available_slots count for the given user.
+    /// Deletes these appointments from the database and updates the user's information.
     ///
-    /// Notice appointments are only de-linked from users, but not actually removed. This is because the [Gatekeeper]
-    /// does not actually hold any [ExtendedAppointment](crate::extended_appointment::ExtendedAppointment) data,
-    /// just references to them.
-    pub(crate) fn delete_appointments_from_memory(
-        &self,
-        appointments: &HashMap<UUID, UserId>,
-    ) -> HashMap<UserId, UserInfo> {
-        let mut updated_users = HashMap::new();
-        let mut registered_users = self.registered_users.lock().unwrap();
+    /// If `refund` is set, the appointments owners will get their slots refunded back.
+    ///
+    /// DISCUSS: When `refund` is `false` we don't give back the slots to the user for the deleted appointments.
+    /// This is to discourage misbehavior (sending bad appointments, either non-decryptable or rejected by the network).
+    pub(crate) fn delete_appointments(&self, appointments: Vec<UUID>, refund: bool) {
+        let mut dbm = self.dbm.lock().unwrap();
 
-        for (uuid, user_id) in appointments {
-            // Remove the appointment from the appointment list and update the available slots
-            if let Some(user_info) = registered_users.get_mut(user_id) {
-                if let Some(x) = user_info.appointments.remove(uuid) {
-                    user_info.available_slots += x;
-                }
-                updated_users.insert(*user_id, user_info.clone());
-            };
+        let updated_users = if refund {
+            let mut updated_users = HashMap::new();
+            let mut registered_users = self.registered_users.lock().unwrap();
+            // Give back the consumed slots to each user.
+            for uuid in appointments.iter() {
+                let (user_id, blob_size) = dbm.get_appointment_user_and_length(*uuid).unwrap();
+                registered_users.get_mut(&user_id).unwrap().available_slots +=
+                    compute_appointment_slots(blob_size, ENCRYPTED_BLOB_MAX_SIZE);
+                updated_users.insert(user_id, registered_users[&user_id]);
+            }
+            updated_users
+        } else {
+            // No updated users.
+            HashMap::new()
+        };
+
+        // An optimization for the case when only one appointment is being deleted without refunding.
+        // This avoids creating a DB transaction for a single query.
+        if appointments.len() == 1 && updated_users.is_empty() {
+            dbm.remove_appointment(appointments[0])
+        } else {
+            dbm.batch_remove_appointments(&appointments, &updated_users);
         }
-
-        updated_users
     }
 }
 
@@ -304,16 +295,28 @@ impl chain::Listen for Gatekeeper {
     /// Handles the monitoring process by the [Gatekeeper].
     ///
     /// This is mainly used to keep track of time and expire / outdate subscriptions when needed.
-    fn block_connected(&self, block: &bitcoin::Block, height: u32) {
-        log::info!("New block received: {}", block.block_hash());
+    fn filtered_block_connected(
+        &self,
+        header: &bitcoin::block::Header,
+        _: &chain::transaction::TransactionData,
+        height: u32,
+    ) {
+        log::info!("New block received: {}", header.block_hash());
 
         // Expired user deletion is delayed. Users are deleted when their subscription is outdated, not expired.
-        let outdated_users = self.get_outdated_user_ids(height);
-        self.registered_users
-            .lock()
-            .unwrap()
-            .retain(|id, _| !outdated_users.contains(id));
-        self.dbm.lock().unwrap().batch_remove_users(&outdated_users);
+        let outdated_users = self.get_outdated_users(height);
+        if !outdated_users.is_empty() {
+            // Remove the outdated users from memory first.
+            {
+                let mut registered_users = self.registered_users.lock().unwrap();
+                // Removing each outdated user in a loop is more efficient than retaining non-outdated users
+                // because retaining would loop over all the available users which is always more than the outdated ones.
+                for outdated_user in outdated_users.iter() {
+                    registered_users.remove(outdated_user);
+                }
+            }
+            self.dbm.lock().unwrap().batch_remove_users(&outdated_users);
+        }
 
         // Update last known block height
         self.last_known_block_height
@@ -321,7 +324,7 @@ impl chain::Listen for Gatekeeper {
     }
 
     /// Handles reorgs in the [Gatekeeper]. Simply updates the last_known_block_height.
-    fn block_disconnected(&self, header: &bitcoin::BlockHeader, height: u32) {
+    fn block_disconnected(&self, header: &bitcoin::block::Header, height: u32) {
         log::warn!("Block disconnected: {}", header.block_hash());
         // There's nothing to be done here but updating the last known block
         self.last_known_block_height
@@ -333,13 +336,12 @@ impl chain::Listen for Gatekeeper {
 mod tests {
     use super::*;
 
-    use crate::dbm::Error as DBError;
-    use crate::test_utils::{
-        generate_dummy_appointment, generate_dummy_appointment_with_user, generate_uuid,
-        get_random_user_id, Blockchain,
-    };
+    use crate::test_utils::{generate_dummy_appointment_with_user, get_random_tracker, Blockchain};
     use lightning::chain::Listen;
     use teos_common::cryptography::{get_random_bytes, get_random_keypair};
+    use teos_common::test_utils::get_random_user_id;
+
+    use crate::responder::ConfirmationStatus;
 
     const SLOTS: u32 = 21;
     const DURATION: u32 = 500;
@@ -363,21 +365,11 @@ mod tests {
             &self.registered_users
         }
 
-        pub(crate) fn add_outdated_user(
-            &self,
-            user_id: UserId,
-            outdates_at: u32,
-            appointments: Option<Vec<UUID>>,
-        ) {
+        pub(crate) fn add_outdated_user(&self, user_id: UserId, outdates_at: u32) {
             self.add_update_user(user_id).unwrap();
             let mut registered_users = self.registered_users.lock().unwrap();
-            let mut user = registered_users.get_mut(&user_id).unwrap();
+            let user = registered_users.get_mut(&user_id).unwrap();
             user.subscription_expiry = outdates_at - self.expiry_delta;
-            if let Some(uuids) = appointments {
-                for uuid in uuids.iter() {
-                    user.appointments.insert(*uuid, 1);
-                }
-            }
         }
     }
 
@@ -443,7 +435,7 @@ mod tests {
 
         // Let's now provide data generated by an actual user, still the user is unknown
         let (user_sk, user_pk) = get_random_keypair();
-        let signature = cryptography::sign(message, &user_sk).unwrap();
+        let signature = cryptography::sign(message, &user_sk);
         assert_eq!(
             gatekeeper.authenticate_user(message, &signature),
             Err(AuthenticationFailure("User not found."))
@@ -472,7 +464,11 @@ mod tests {
         // The data should have been also added to the database
         assert_eq!(
             gatekeeper.dbm.lock().unwrap().load_user(user_id).unwrap(),
-            UserInfo::new(receipt.available_slots(), receipt.subscription_expiry())
+            UserInfo::new(
+                receipt.available_slots(),
+                receipt.subscription_start(),
+                receipt.subscription_expiry()
+            )
         );
 
         // Let generate a new block and add the user again to check that both the slots and expiry are updated.
@@ -482,13 +478,10 @@ mod tests {
             .store(chain.get_block_count(), Ordering::Relaxed);
         let updated_receipt = gatekeeper.add_update_user(user_id).unwrap();
 
-        assert_eq!(
-            updated_receipt.available_slots(),
-            receipt.available_slots() * 2
-        );
+        assert_eq!(updated_receipt.available_slots(), SLOTS * 2);
         assert_eq!(
             updated_receipt.subscription_expiry(),
-            receipt.subscription_expiry() + 1
+            START_HEIGHT as u32 + DURATION * 2
         );
 
         // Data in the database should have been updated too
@@ -496,6 +489,7 @@ mod tests {
             gatekeeper.dbm.lock().unwrap().load_user(user_id).unwrap(),
             UserInfo::new(
                 updated_receipt.available_slots(),
+                updated_receipt.subscription_start(),
                 updated_receipt.subscription_expiry()
             )
         );
@@ -519,6 +513,7 @@ mod tests {
             gatekeeper.dbm.lock().unwrap().load_user(user_id).unwrap(),
             UserInfo::new(
                 updated_receipt.available_slots(),
+                updated_receipt.subscription_start(),
                 updated_receipt.subscription_expiry()
             )
         );
@@ -547,25 +542,32 @@ mod tests {
         let available_slots = gatekeeper
             .add_update_appointment(user_id, uuid, &appointment)
             .unwrap();
+        // Simulate the watcher adding the appointment in the database.
+        gatekeeper
+            .dbm
+            .lock()
+            .unwrap()
+            .store_appointment(uuid, &appointment)
+            .unwrap();
 
-        assert!(gatekeeper.registered_users.lock().unwrap()[&user_id]
-            .appointments
-            .contains_key(&uuid));
+        let (_, user_locators) = gatekeeper.get_user_info(user_id).unwrap();
+        assert!(user_locators.contains(&appointment.locator()));
         assert_eq!(slots_before, available_slots + 1);
 
-        // Slots should have been updated in the database too. Notice the appointment won't be there yet
-        // given the Watcher is responsible for adding it, and it will do so after calling this method
+        // Slots should have been updated in the database too.
         let mut loaded_user = gatekeeper.dbm.lock().unwrap().load_user(user_id).unwrap();
         assert_eq!(loaded_user.available_slots, available_slots);
 
-        // Adding the exact same appointment should leave the slots count unchanged
+        // Adding the exact same appointment should leave the slots count unchanged.
+        // We don't really need to update the appointment in the DB since it's the very same appointment.
         let mut updated_slot_count = gatekeeper
             .add_update_appointment(user_id, uuid, &appointment)
             .unwrap();
-        assert!(gatekeeper.registered_users.lock().unwrap()[&user_id]
-            .appointments
-            .contains_key(&uuid));
+
+        let (_, user_locators) = gatekeeper.get_user_info(user_id).unwrap();
+        assert!(user_locators.contains(&appointment.locator()));
         assert_eq!(updated_slot_count, available_slots);
+
         loaded_user = gatekeeper.dbm.lock().unwrap().load_user(user_id).unwrap();
         assert_eq!(loaded_user.available_slots, updated_slot_count);
 
@@ -575,10 +577,18 @@ mod tests {
         updated_slot_count = gatekeeper
             .add_update_appointment(user_id, uuid, &bigger_appointment)
             .unwrap();
-        assert!(gatekeeper.registered_users.lock().unwrap()[&user_id]
-            .appointments
-            .contains_key(&uuid));
+        // Simulate the watcher updating the appointment in the database.
+        gatekeeper
+            .dbm
+            .lock()
+            .unwrap()
+            .update_appointment(uuid, &bigger_appointment)
+            .unwrap();
+
+        let (_, user_locators) = gatekeeper.get_user_info(user_id).unwrap();
+        assert!(user_locators.contains(&appointment.locator()));
         assert_eq!(updated_slot_count, available_slots - 1);
+
         loaded_user = gatekeeper.dbm.lock().unwrap().load_user(user_id).unwrap();
         assert_eq!(loaded_user.available_slots, updated_slot_count);
 
@@ -586,26 +596,43 @@ mod tests {
         updated_slot_count = gatekeeper
             .add_update_appointment(user_id, uuid, &appointment)
             .unwrap();
-        assert!(gatekeeper.registered_users.lock().unwrap()[&user_id]
-            .appointments
-            .contains_key(&uuid));
+        // Simulate the watcher updating the appointment in the database.
+        gatekeeper
+            .dbm
+            .lock()
+            .unwrap()
+            .update_appointment(uuid, &appointment)
+            .unwrap();
+
+        let (_, user_locators) = gatekeeper.get_user_info(user_id).unwrap();
+        assert!(user_locators.contains(&appointment.locator()));
         assert_eq!(updated_slot_count, available_slots);
+
         loaded_user = gatekeeper.dbm.lock().unwrap().load_user(user_id).unwrap();
         assert_eq!(loaded_user.available_slots, updated_slot_count);
 
         // Adding an appointment with a different uuid should not count as an update
-        let new_uuid = generate_uuid();
+        let (uuid, appointment) = generate_dummy_appointment_with_user(user_id, None);
         updated_slot_count = gatekeeper
-            .add_update_appointment(user_id, new_uuid, &appointment)
+            .add_update_appointment(user_id, uuid, &appointment)
             .unwrap();
-        assert!(gatekeeper.registered_users.lock().unwrap()[&user_id]
-            .appointments
-            .contains_key(&new_uuid));
+        // Simulate the watcher adding the appointment in the database.
+        gatekeeper
+            .dbm
+            .lock()
+            .unwrap()
+            .store_appointment(uuid, &appointment)
+            .unwrap();
+
+        let (_, user_locators) = gatekeeper.get_user_info(user_id).unwrap();
+        assert!(user_locators.contains(&appointment.locator()));
         assert_eq!(updated_slot_count, available_slots - 1);
+
         loaded_user = gatekeeper.dbm.lock().unwrap().load_user(user_id).unwrap();
         assert_eq!(loaded_user.available_slots, updated_slot_count);
 
         // Finally, trying to add an appointment when the user has no enough slots should fail
+        let (uuid, appointment) = generate_dummy_appointment_with_user(user_id, None);
         gatekeeper
             .registered_users
             .lock()
@@ -614,9 +641,10 @@ mod tests {
             .unwrap()
             .available_slots = 0;
         assert!(matches!(
-            gatekeeper.add_update_appointment(user_id, generate_uuid(), &appointment),
+            gatekeeper.add_update_appointment(user_id, uuid, &appointment),
             Err(NotEnoughSlots)
         ));
+
         // The entry in the database should remain unchanged in this case
         loaded_user = gatekeeper.dbm.lock().unwrap().load_user(user_id).unwrap();
         assert_eq!(loaded_user.available_slots, updated_slot_count);
@@ -662,148 +690,179 @@ mod tests {
 
         // Initially, there are not outdated users, so querying any block height should return an empty map
         for i in 0..start_height {
-            assert_eq!(gatekeeper.get_outdated_users(i).len(), 0);
+            assert_eq!(gatekeeper.get_outdated_users(i), vec![]);
         }
 
         // Adding a user whose subscription is outdated should return an entry
         let user_id = get_random_user_id();
         gatekeeper.add_update_user(user_id).unwrap();
 
-        // Add also an appointment so we can check the returned data
-        let appointment = generate_dummy_appointment(None);
-        let uuid = generate_uuid();
-        gatekeeper
-            .add_update_appointment(user_id, uuid, &appointment)
-            .unwrap();
-
         // Check that data is not yet outdated
-        assert_eq!(gatekeeper.get_outdated_users(start_height).len(), 0);
+        assert_eq!(gatekeeper.get_outdated_users(start_height), vec![]);
 
         // Add an outdated user and check again
-        gatekeeper.add_outdated_user(user_id, start_height, None);
-        let outdated_users = gatekeeper.get_outdated_users(start_height);
-        assert_eq!(outdated_users.len(), 1);
-        assert_eq!(outdated_users[&user_id], HashSet::from_iter([uuid]));
+        gatekeeper.add_outdated_user(user_id, start_height);
+        assert_eq!(gatekeeper.get_outdated_users(start_height), vec![user_id]);
     }
 
     #[test]
-    fn test_get_outdated_appointments() {
-        let start_height = START_HEIGHT as u32 + EXPIRY_DELTA;
-        let gatekeeper = init_gatekeeper(&Blockchain::default().with_height(start_height as usize));
-
-        // get_outdated_appointments returns a list of appointments that were outdated at a given block height, indistinguishably of their user.
-
-        // If there are no outdated users, there cannot be outdated appointments
-        for i in 0..start_height {
-            assert_eq!(gatekeeper.get_outdated_appointments(i).len(), 0);
-        }
-
-        // Adding data about different users and appointments should return a flattened list of appointments
-        let user1_id = get_random_user_id();
-        let user2_id = get_random_user_id();
-        let uuid1 = generate_uuid();
-        let uuid2 = generate_uuid();
-
-        // Manually set the user expiry for the test
-        for (user_id, uuid) in [(user1_id, uuid1), (user2_id, uuid2)] {
-            gatekeeper.add_outdated_user(user_id, start_height, Some(Vec::from_iter([uuid])));
-        }
-
-        let outdated_appointments = gatekeeper.get_outdated_appointments(start_height);
-        assert_eq!(outdated_appointments.len(), 2);
-        assert!(outdated_appointments.contains(&uuid1));
-        assert!(outdated_appointments.contains(&uuid2));
-    }
-
-    #[test]
-    fn test_delete_appointments_from_memory() {
+    fn test_delete_appointments_without_refund() {
         let gatekeeper = init_gatekeeper(&Blockchain::default().with_height(START_HEIGHT));
+        let n_users = 100;
+        let n_apps = 10;
+        let mut uuids_to_delete = Vec::new();
+        let mut rest = Vec::new();
+        let mut trackers = Vec::new();
+        let mut users_info = HashMap::new();
 
-        // delete_appointments will remove a list of appointments from the Gatekeeper (as long as they exist)
-        let mut all_appointments = HashMap::new();
-        let mut to_be_deleted = HashMap::new();
-        let mut rest = HashMap::new();
-        for i in 1..11 {
+        for _ in 0..n_users {
             let user_id = get_random_user_id();
-            let uuid = generate_uuid();
-            all_appointments.insert(uuid, user_id);
-
-            if i % 2 == 0 {
-                to_be_deleted.insert(uuid, user_id);
-            } else {
-                rest.insert(uuid, user_id);
-            }
-        }
-
-        // Calling the method with unknown data should work but do nothing
-        assert!(gatekeeper.registered_users.lock().unwrap().is_empty());
-        assert!(gatekeeper
-            .delete_appointments_from_memory(&all_appointments)
-            .is_empty());
-
-        // If there's matching data in the gatekeeper it should be deleted
-        for (uuid, user_id) in to_be_deleted.iter() {
-            gatekeeper.add_update_user(*user_id).unwrap();
-            gatekeeper
-                .add_update_appointment(*user_id, *uuid, &generate_dummy_appointment(None))
-                .unwrap();
-        }
-
-        // Check before deleting
-        assert_eq!(gatekeeper.registered_users.lock().unwrap().len(), 5);
-        for (uuid, user_id) in to_be_deleted.iter() {
-            assert!(gatekeeper.registered_users.lock().unwrap()[user_id]
-                .appointments
-                .contains_key(uuid));
-
-            // The slot count should be decreased now too (both in memory and in the database)
-            assert_ne!(
-                gatekeeper.registered_users.lock().unwrap()[user_id].available_slots,
-                gatekeeper.subscription_slots
-            );
-            assert_ne!(
+            gatekeeper.add_update_user(user_id).unwrap();
+            for i in 0..n_apps {
+                let (uuid, appointment) = generate_dummy_appointment_with_user(user_id, None);
+                gatekeeper
+                    .add_update_appointment(user_id, uuid, &appointment)
+                    .unwrap();
+                // Add the appointment to the database. This is normally done by the Watcher.
                 gatekeeper
                     .dbm
                     .lock()
                     .unwrap()
-                    .load_user(*user_id)
-                    .unwrap()
-                    .available_slots,
-                gatekeeper.subscription_slots
-            );
-        }
-        for (_, user_id) in rest.iter() {
-            assert!(!gatekeeper
-                .registered_users
-                .lock()
-                .unwrap()
-                .contains_key(user_id));
+                    .store_appointment(uuid, &appointment)
+                    .unwrap();
+                if i % 2 == 0 {
+                    uuids_to_delete.push(uuid);
+                } else {
+                    rest.push(uuid);
+                }
+                // Also trigger some of these appointments as trackers.
+                if i % 5 == 0 {
+                    gatekeeper
+                        .dbm
+                        .lock()
+                        .unwrap()
+                        .store_tracker(
+                            uuid,
+                            &get_random_tracker(user_id, ConfirmationStatus::ConfirmedIn(42)),
+                        )
+                        .unwrap();
+                    trackers.push(uuid);
+                }
+            }
+            users_info.insert(user_id, gatekeeper.get_user_info(user_id).unwrap().0);
         }
 
-        // And after
-        gatekeeper.delete_appointments_from_memory(&all_appointments);
-        for (uuid, user_id) in to_be_deleted.iter() {
-            assert!(!gatekeeper.registered_users.lock().unwrap()[user_id]
-                .appointments
-                .contains_key(uuid));
+        // Delete these appointments without refunding their owners.
+        gatekeeper.delete_appointments(uuids_to_delete.clone(), false);
 
-            // The slot count is back to default
-            assert_eq!(
-                gatekeeper.registered_users.lock().unwrap()[user_id].available_slots,
-                gatekeeper.subscription_slots
-            );
+        for uuid in uuids_to_delete.clone() {
+            assert!(!gatekeeper.dbm.lock().unwrap().appointment_exists(uuid));
         }
-        for (_, user_id) in rest.iter() {
-            assert!(!gatekeeper
-                .registered_users
-                .lock()
-                .unwrap()
-                .contains_key(user_id));
+        for uuid in rest {
+            assert!(gatekeeper.dbm.lock().unwrap().appointment_exists(uuid));
+        }
+        for uuid in trackers {
+            if uuids_to_delete.contains(&uuid) {
+                // The tracker should be deleted as well.
+                assert!(!gatekeeper.dbm.lock().unwrap().tracker_exists(uuid));
+            } else {
+                assert!(gatekeeper.dbm.lock().unwrap().tracker_exists(uuid));
+            }
+        }
+
+        for (user_id, user_info_before_deletion) in users_info {
+            // Since `refund` was false, the users' slots should not have changed after deleting appointments.
+            let (user_info_after_deletion, _) = gatekeeper.get_user_info(user_id).unwrap();
+            assert_eq!(user_info_after_deletion, user_info_before_deletion);
         }
     }
 
     #[test]
-    fn test_block_connected() {
+    fn test_delete_appointments_with_refund() {
+        let gatekeeper = init_gatekeeper(&Blockchain::default().with_height(START_HEIGHT));
+        let n_users = 100;
+        let n_apps = 10;
+        let mut uuids_to_delete = Vec::new();
+        let mut rest = Vec::new();
+        let mut trackers = Vec::new();
+        let mut users_remaining_slots = HashMap::new();
+
+        for _ in 0..n_users {
+            let user_id = get_random_user_id();
+            gatekeeper.add_update_user(user_id).unwrap();
+            let mut user_remaining_slots =
+                gatekeeper.get_user_info(user_id).unwrap().0.available_slots;
+            for i in 0..n_apps {
+                let (uuid, appointment) = generate_dummy_appointment_with_user(user_id, None);
+                gatekeeper
+                    .add_update_appointment(user_id, uuid, &appointment)
+                    .unwrap();
+                // Add the appointment to the database. This is normally done by the Watcher.
+                gatekeeper
+                    .dbm
+                    .lock()
+                    .unwrap()
+                    .store_appointment(uuid, &appointment)
+                    .unwrap();
+                if i % 2 == 0 {
+                    // We don't reduce the remaining slots for the appointments which are
+                    // going to delete since we will refund their owners.
+                    uuids_to_delete.push(uuid);
+                } else {
+                    rest.push(uuid);
+                    user_remaining_slots -= compute_appointment_slots(
+                        appointment.encrypted_blob().len(),
+                        ENCRYPTED_BLOB_MAX_SIZE,
+                    );
+                }
+                // Also trigger some of these appointments as trackers.
+                if i % 5 == 0 {
+                    gatekeeper
+                        .dbm
+                        .lock()
+                        .unwrap()
+                        .store_tracker(
+                            uuid,
+                            &get_random_tracker(user_id, ConfirmationStatus::ConfirmedIn(42)),
+                        )
+                        .unwrap();
+                    trackers.push(uuid);
+                }
+            }
+            users_remaining_slots.insert(user_id, user_remaining_slots);
+        }
+
+        // Delete these appointments and refund their owners their slots back.
+        gatekeeper.delete_appointments(uuids_to_delete.clone(), true);
+
+        for uuid in uuids_to_delete.clone() {
+            assert!(!gatekeeper.dbm.lock().unwrap().appointment_exists(uuid));
+        }
+        for uuid in rest {
+            assert!(gatekeeper.dbm.lock().unwrap().appointment_exists(uuid));
+        }
+        for uuid in trackers {
+            if uuids_to_delete.contains(&uuid) {
+                // The tracker should be deleted as well.
+                assert!(!gatekeeper.dbm.lock().unwrap().tracker_exists(uuid));
+            } else {
+                assert!(gatekeeper.dbm.lock().unwrap().tracker_exists(uuid));
+            }
+        }
+
+        for (user_id, correct_remaining_slots) in users_remaining_slots {
+            let remaining_slots_from_db =
+                gatekeeper.get_user_info(user_id).unwrap().0.available_slots;
+            assert_eq!(remaining_slots_from_db, correct_remaining_slots);
+            assert_eq!(
+                gatekeeper.registered_users.lock().unwrap()[&user_id].available_slots,
+                correct_remaining_slots
+            );
+        }
+    }
+
+    #[test]
+    fn test_filtered_block_connected() {
         // block_connected in the Gatekeeper is used to keep track of time in order to manage the users' subscription expiry.
         // Remove users that get outdated at the new block's height from registered_users and the database.
         let mut chain = Blockchain::default().with_height(START_HEIGHT);
@@ -815,7 +874,7 @@ mod tests {
         let user3_id = get_random_user_id();
 
         for user_id in &[user1_id, user2_id, user3_id] {
-            gatekeeper.add_outdated_user(*user_id, chain.tip().height + 1, None)
+            gatekeeper.add_outdated_user(*user_id, chain.tip().height + 1)
         }
 
         // Connect a new block. Outdated users are deleted
@@ -828,10 +887,7 @@ mod tests {
                 .lock()
                 .unwrap()
                 .contains_key(user_id));
-            assert!(matches!(
-                gatekeeper.dbm.lock().unwrap().load_user(*user_id),
-                Err(DBError::NotFound)
-            ));
+            assert!(gatekeeper.dbm.lock().unwrap().load_user(*user_id).is_none());
         }
 
         // Check that the last_known_block_header has been properly updated

teos/src/lib.rs

@@ -2,6 +2,8 @@
 //!
 //! A watchtower implementation written in Rust.
 
+// FIXME: This is a temporary fix. See https://github.com/tokio-rs/prost/issues/661
+#[allow(clippy::derive_partial_eq_without_eq)]
 pub mod protos {
     tonic::include_proto!("teos.v2");
 }
@@ -19,6 +21,8 @@ pub mod gatekeeper;
 pub mod responder;
 #[doc(hidden)]
 mod rpc_errors;
+pub mod tls;
+mod tx_index;
 pub mod watcher;
 
 #[cfg(test)]

teos/src/main.rs

@@ -1,57 +1,59 @@
-use simple_logger::init_with_level;
+use log::LevelFilter;
+use simple_logger::SimpleLogger;
 use std::fs;
+use std::io::ErrorKind;
 use std::ops::{Deref, DerefMut};
-use std::str::FromStr;
 use std::sync::{Arc, Condvar, Mutex};
 use structopt::StructOpt;
 use tokio::task;
-use tonic::transport::Server;
+use tonic::transport::{Certificate, Server, ServerTlsConfig};
 
-use bitcoin::network::constants::Network;
+use bitcoin::network::Network;
 use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
-use bitcoincore_rpc::{Auth, Client};
+use bitcoincore_rpc::{Auth, Client, RpcApi};
 use lightning_block_sync::init::validate_best_block_header;
 use lightning_block_sync::poll::{
     ChainPoller, Poll, Validate, ValidatedBlock, ValidatedBlockHeader,
 };
-use lightning_block_sync::{BlockSource, SpvClient, UnboundedCache};
+use lightning_block_sync::{BlockSource, BlockSourceError, SpvClient, UnboundedCache};
 
-use teos::api::http;
 use teos::api::internal::InternalAPI;
+use teos::api::{http, tor::TorAPI};
 use teos::bitcoin_cli::BitcoindClient;
 use teos::carrier::Carrier;
 use teos::chain_monitor::ChainMonitor;
-use teos::config::{self, Config, Opt};
+use teos::config::{self, AuthMethod, Config, Opt};
 use teos::dbm::DBM;
 use teos::gatekeeper::Gatekeeper;
+use teos::protos as msgs;
 use teos::protos::private_tower_services_server::PrivateTowerServicesServer;
 use teos::protos::public_tower_services_server::PublicTowerServicesServer;
 use teos::responder::Responder;
+use teos::tls::tls_init;
 use teos::watcher::Watcher;
 
+use teos_common::constants::IRREVOCABLY_RESOLVED;
 use teos_common::cryptography::get_random_keypair;
-use teos_common::UserId;
+use teos_common::TowerId;
 
 async fn get_last_n_blocks<B, T>(
     poller: &mut ChainPoller<B, T>,
     mut last_known_block: ValidatedBlockHeader,
     n: usize,
-) -> Vec<ValidatedBlock>
+) -> Result<Vec<ValidatedBlock>, BlockSourceError>
 where
     B: DerefMut<Target = T> + Sized + Send + Sync,
     T: BlockSource,
 {
-    let mut last_n_blocks = Vec::new();
+    let mut last_n_blocks = Vec::with_capacity(n);
     for _ in 0..n {
-        let block = poller.fetch_block(&last_known_block).await.unwrap();
-        last_known_block = poller
-            .look_up_previous_header(&last_known_block)
-            .await
-            .unwrap();
+        log::debug!("Fetching block #{}", last_known_block.height);
+        let block = poller.fetch_block(&last_known_block).await?;
+        last_known_block = poller.look_up_previous_header(&last_known_block).await?;
         last_n_blocks.push(block);
     }
 
-    last_n_blocks
+    Ok(last_n_blocks)
 }
 
 fn create_new_tower_keypair(db: &DBM) -> (SecretKey, PublicKey) {
@@ -64,34 +66,61 @@ fn create_new_tower_keypair(db: &DBM) -> (SecretKey, PublicKey) {
 async fn main() {
     let opt = Opt::from_args();
     let path = config::data_dir_absolute_path(opt.data_dir.clone());
-
+    let conf_file_path = path.join("teos.toml");
     // Create data dir if it does not exist
     fs::create_dir_all(&path).unwrap_or_else(|e| {
-        eprintln!("Cannot create data dir: {:?}", e);
+        eprintln!("Cannot create data dir: {e:?}");
         std::process::exit(1);
     });
 
     // Load conf (from file or defaults) and patch it with the command line parameters received (if any)
-    let mut conf = config::from_file::<Config>(path.join("teos.toml"));
+    let mut conf = config::from_file::<Config>(&conf_file_path);
+    let is_default = conf.is_default();
     conf.patch_with_options(opt);
     conf.verify().unwrap_or_else(|e| {
-        eprintln!("{}", e);
+        eprintln!("{e}");
         std::process::exit(1);
     });
 
     // Set log level
-    if conf.debug {
-        init_with_level(log::Level::Debug).unwrap()
-    } else {
-        init_with_level(log::Level::Info).unwrap()
-    }
+    SimpleLogger::new()
+        .with_level(if conf.deps_debug {
+            LevelFilter::Debug
+        } else {
+            LevelFilter::Warn
+        })
+        .with_module_level(
+            "teos",
+            if conf.debug {
+                LevelFilter::Debug
+            } else {
+                LevelFilter::Info
+            },
+        )
+        .init()
+        .unwrap();
 
     // Create network dir
     let path_network = path.join(conf.btc_network.clone());
     fs::create_dir_all(&path_network).unwrap_or_else(|e| {
-        eprintln!("Cannot create network dir: {:?}", e);
+        eprintln!("Cannot create network dir: {e:?}");
         std::process::exit(1);
     });
+
+    // Log default data dir
+    log::info!("Default data directory: {:?}", &path);
+
+    // Log datadir path
+    log::info!("Using data directory: {:?}", &path_network);
+
+    // Log config file path based on whether the config file is found or not
+    if is_default {
+        log::info!("Config file: {:?} (not found, skipping)", &conf_file_path);
+    } else {
+        log::info!("Config file: {:?}", &conf_file_path);
+        conf.log_non_default_options();
+    }
+
     let dbm = Arc::new(Mutex::new(
         DBM::new(path_network.join("teos_db.sql3")).unwrap(),
     ));
@@ -103,24 +132,30 @@ async fn main() {
         if conf.overwrite_key {
             log::info!("Overwriting tower keys");
             create_new_tower_keypair(&locked_db)
+        } else if let Some(sk) = locked_db.load_tower_key() {
+            (sk, PublicKey::from_secret_key(&Secp256k1::new(), &sk))
         } else {
-            match locked_db.load_tower_key() {
-                Ok(sk) => (sk, PublicKey::from_secret_key(&Secp256k1::new(), &sk)),
-                Err(_) => {
-                    log::info!("Tower keys not found. Creating a fresh set");
-                    create_new_tower_keypair(&locked_db)
-                }
-            }
+            log::info!("Tower keys not found. Creating a fresh set");
+            create_new_tower_keypair(&locked_db)
         }
     };
-    log::info!("tower_id: {}", tower_pk);
+    log::info!("tower_id: {tower_pk}");
+
+    let btc_rpc_auth = match conf.get_auth_method() {
+        AuthMethod::CookieFile => {
+            Auth::CookieFile(config::data_dir_absolute_path(conf.btc_rpc_cookie))
+        }
+        AuthMethod::UserPass => Auth::UserPass(conf.btc_rpc_user, conf.btc_rpc_password),
+        // Notice an invalid conf would have failed on `Config::verify()`
+        _ => unreachable!("A verified conf will only have one of these two auth methods"),
+    };
 
     // Initialize our bitcoind client
     let (bitcoin_cli, bitcoind_reachable) = match BitcoindClient::new(
         &conf.btc_rpc_connect,
         conf.btc_rpc_port,
-        &conf.btc_rpc_user,
-        &conf.btc_rpc_password,
+        btc_rpc_auth.clone(),
+        &conf.btc_network,
     )
     .await
     {
@@ -129,8 +164,12 @@ async fn main() {
             Arc::new((Mutex::new(true), Condvar::new())),
         ),
         Err(e) => {
-            log::error!("Failed to connect to bitcoind client: {}", e);
-            return;
+            let e_msg = match e.kind() {
+                ErrorKind::InvalidData => "invalid btcrpcuser or btcrpcpassword".into(),
+                _ => e.to_string(),
+            };
+            log::error!("Failed to connect to bitcoind. Error: {e_msg}");
+            std::process::exit(1);
         }
     };
 
@@ -143,27 +182,81 @@ async fn main() {
     };
     let rpc = Arc::new(
         Client::new(
-            &format!("{}{}:{}", schema, conf.btc_rpc_connect, conf.btc_rpc_port),
-            Auth::UserPass(conf.btc_rpc_user.clone(), conf.btc_rpc_password.clone()),
+            &format!("{schema}{}:{}", conf.btc_rpc_connect, conf.btc_rpc_port),
+            btc_rpc_auth,
         )
         .unwrap(),
     );
     let mut derefed = bitcoin_cli.deref();
     // Load last known block from DB if found. Poll it from Bitcoind otherwise.
-    let tip = if let Ok(block_hash) = dbm.lock().unwrap().load_last_known_block() {
-        derefed
+    let last_known_block = dbm.lock().unwrap().load_last_known_block();
+    let tip = if let Some(block_hash) = last_known_block {
+        let mut last_known_header = derefed
             .get_header(&block_hash, None)
             .await
             .unwrap()
             .validate(block_hash)
-            .unwrap()
-    } else {
-        validate_best_block_header(&mut derefed).await.unwrap()
-    };
-    log::info!("Last known block: {}", tip.header.block_hash());
+            .unwrap();
 
-    let mut poller = ChainPoller::new(&mut derefed, Network::from_str(&conf.btc_network).unwrap());
-    let last_n_blocks = get_last_n_blocks(&mut poller, tip, 6).await;
+        log::info!(
+            "Last known block: {} (height: {})",
+            last_known_header.header.block_hash(),
+            last_known_header.height
+        );
+
+        // If we are running in pruned mode some data may be missing (if we happen to have been offline for a while)
+        if let Some(prune_height) = rpc.get_blockchain_info().unwrap().prune_height {
+            if last_known_header.height - IRREVOCABLY_RESOLVED + 1 < prune_height as u32 {
+                log::warn!(
+                    "Cannot load blocks in the range {}-{}. Chain has gone too far out of sync",
+                    last_known_header.height - IRREVOCABLY_RESOLVED + 1,
+                    last_known_header.height
+                );
+                if conf.force_update {
+                    log::info!("Forcing a backend update");
+                    // We want to grab the first IRREVOCABLY_RESOLVED we know about for the initial cache
+                    // So we can perform transitions from there onwards.
+                    let target_height = prune_height + IRREVOCABLY_RESOLVED as u64;
+                    let target_hash = rpc.get_block_hash(target_height).unwrap();
+                    last_known_header = derefed
+                        .get_header(
+                            &rpc.get_block_hash(target_height).unwrap(),
+                            Some(target_height as u32),
+                        )
+                        .await
+                        .unwrap()
+                        .validate(target_hash)
+                        .unwrap();
+                } else {
+                    log::error!(
+                        "The underlying chain has gone too far out of sync. The tower block cache cannot be initialized. Run with --forceupdate to force update. THIS WILL, POTENTIALLY, MAKE THE TOWER MISS SOME OF ITS APPOINTMENTS"
+                    );
+                    std::process::exit(1);
+                }
+            }
+        }
+        last_known_header
+    } else {
+        validate_best_block_header(&derefed).await.unwrap()
+    };
+
+    // DISCUSS: This is not really required (and only triggered in regtest). This is only in place so the caches can be
+    // populated with enough blocks mainly because the size of the cache is based on the amount of blocks passed when initializing.
+    // However, we could add an additional parameter to specify the size of the cache, and initialize with however may blocks we
+    // could pull from the backend. Adding this functionality just for regtest seemed unnecessary though, hence the check.
+    if tip.height < IRREVOCABLY_RESOLVED {
+        log::error!(
+            "Not enough blocks to start teosd (required: {IRREVOCABLY_RESOLVED}). Mine at least {} more",
+            IRREVOCABLY_RESOLVED - tip.height
+        );
+        std::process::exit(1);
+    }
+
+    log::info!(
+        "Current chain tip: {} (height: {})",
+        tip.header.block_hash(),
+        tip.height
+    );
 
     // Build components
     let gatekeeper = Arc::new(Gatekeeper::new(
@@ -174,17 +267,38 @@ async fn main() {
         dbm.clone(),
     ));
 
-    let carrier = Carrier::new(rpc, bitcoind_reachable.clone(), tip.deref().height);
-    let responder = Arc::new(Responder::new(carrier, gatekeeper.clone(), dbm.clone()));
-    let watcher = Arc::new(Watcher::new(
-        gatekeeper.clone(),
-        responder.clone(),
-        last_n_blocks,
-        tip.height,
-        tower_sk,
-        UserId(tower_pk),
-        dbm.clone(),
-    ));
+    let mut poller = ChainPoller::new(
+        &mut derefed,
+        Network::from_core_arg(&conf.btc_network).unwrap(),
+    );
+    let (responder, watcher) = {
+        let last_n_blocks = get_last_n_blocks(&mut poller, tip, IRREVOCABLY_RESOLVED as usize)
+            .await.unwrap_or_else(|e| {
+                // I'm pretty sure this can only happen if we are pulling blocks from the target to the prune height, and by the time we get to
+                // the end at least one has been pruned.
+                log::error!("Couldn't load the latest {IRREVOCABLY_RESOLVED} blocks. Please try again (Error: {})", e.into_inner());
+                std::process::exit(1);
+            }
+        );
+
+        let responder = Arc::new(Responder::new(
+            &last_n_blocks,
+            tip.height,
+            Carrier::new(rpc, bitcoind_reachable.clone(), tip.height),
+            gatekeeper.clone(),
+            dbm.clone(),
+        ));
+        let watcher = Arc::new(Watcher::new(
+            gatekeeper.clone(),
+            responder.clone(),
+            &last_n_blocks[0..6],
+            tip.height,
+            tower_sk,
+            TowerId(tower_pk),
+            dbm.clone(),
+        ));
+        (responder, watcher)
+    };
 
     if watcher.is_fresh() & responder.is_fresh() & gatekeeper.is_fresh() {
         log::info!("Fresh bootstrap");
@@ -193,13 +307,14 @@ async fn main() {
     }
 
     let (shutdown_trigger, shutdown_signal_rpc_api) = triggered::trigger();
-    let shutdown_signal_internal_rpc_api = shutdown_signal_rpc_api.clone();
+    let shutdown_signal_internal_api = shutdown_signal_rpc_api.clone();
     let shutdown_signal_http = shutdown_signal_rpc_api.clone();
     let shutdown_signal_cm = shutdown_signal_rpc_api.clone();
+    let shutdown_signal_tor = shutdown_signal_rpc_api.clone();
 
     // The ordering here actually matters. Listeners are called by order, and we want the gatekeeper to be called
-    // last, so both the Watcher and the Responder can query the necessary data from it during data deletion.
-    let listener = &(watcher.clone(), &(responder, gatekeeper));
+    // first so it updates the users' states and both the Watcher and the Responder operate only on registered users.
+    let listener = &(gatekeeper, &(watcher.clone(), responder));
     let cache = &mut UnboundedCache::new();
     let spv_client = SpvClient::new(tip, poller, cache, listener);
     let mut chain_monitor = ChainMonitor::new(
@@ -217,31 +332,65 @@ async fn main() {
     log::info!("Bootstrap completed. Turning on interfaces");
 
     // Build interfaces
-    let rpc_api = Arc::new(InternalAPI::new(
+    let http_api_addr = format!("{}:{}", conf.api_bind, conf.api_port)
+        .parse()
+        .unwrap();
+    let mut addresses = vec![msgs::NetworkAddress::from_ipv4(
+        conf.api_bind.clone(),
+        conf.api_port,
+    )];
+
+    // Create Tor endpoint if required
+    let tor_api = if conf.tor_support {
+        let tor_api = TorAPI::new(
+            http_api_addr,
+            conf.onion_hidden_service_port,
+            conf.tor_control_port,
+            path_network,
+        )
+        .await;
+        addresses.push(msgs::NetworkAddress::from_torv3(
+            tor_api.get_onion_address(),
+            conf.onion_hidden_service_port,
+        ));
+
+        Some(tor_api)
+    } else {
+        None
+    };
+
+    let internal_api = Arc::new(InternalAPI::new(
         watcher,
+        addresses,
         bitcoind_reachable.clone(),
         shutdown_trigger,
     ));
-    let internal_rpc_api = rpc_api.clone();
+    let internal_api_cloned = internal_api.clone();
 
     let rpc_api_addr = format!("{}:{}", conf.rpc_bind, conf.rpc_port)
         .parse()
         .unwrap();
-    let internal_rpc_api_addr = format!("{}:{}", conf.internal_api_bind, conf.internal_api_port)
-        .parse()
-        .unwrap();
-    let internal_rpc_api_uri = format!(
-        "http://{}:{}",
-        conf.internal_api_bind, conf.internal_api_port
-    );
-    let http_api_addr = format!("{}:{}", conf.api_bind, conf.api_port)
+    let internal_api_addr = format!("{}:{}", conf.internal_api_bind, conf.internal_api_port)
         .parse()
         .unwrap();
 
+    // Generate mtls certificates to data directory so the admin can securely connect
+    // to the server to perform administrative tasks.
+    let (identity, ca_cert) = tls_init(&path).unwrap_or_else(|e| {
+        eprintln!("Couldn't generate tls certificates: {e:?}");
+        std::process::exit(1);
+    });
+
+    let tls = ServerTlsConfig::new()
+        .identity(identity)
+        .client_ca_root(Certificate::from_pem(ca_cert));
+
     // Start tasks
     let private_api_task = task::spawn(async move {
         Server::builder()
-            .add_service(PrivateTowerServicesServer::new(rpc_api))
+            .tls_config(tls)
+            .expect("couldn't configure tls")
+            .add_service(PrivateTowerServicesServer::new(internal_api))
             .serve_with_shutdown(rpc_api_addr, shutdown_signal_rpc_api)
             .await
             .unwrap();
@@ -249,22 +398,50 @@ async fn main() {
 
     let public_api_task = task::spawn(async move {
         Server::builder()
-            .add_service(PublicTowerServicesServer::new(internal_rpc_api))
-            .serve_with_shutdown(internal_rpc_api_addr, shutdown_signal_internal_rpc_api)
+            .add_service(PublicTowerServicesServer::new(internal_api_cloned))
+            .serve_with_shutdown(internal_api_addr, shutdown_signal_internal_api)
             .await
             .unwrap();
     });
 
+    let (http_service_ready, ready_signal_http) = triggered::trigger();
     let http_api_task = task::spawn(http::serve(
         http_api_addr,
-        internal_rpc_api_uri,
+        internal_api_addr,
+        http_service_ready,
         shutdown_signal_http,
     ));
+    ready_signal_http.await;
+
+    // Add Tor Onion Service for public API
+    let mut tor_task = Option::None;
+    let (tor_service_ready, ready_signal_tor) = triggered::trigger();
+    if let Some(tor_api) = tor_api {
+        log::info!("Starting up Tor hidden service");
+
+        tor_task = Some(task::spawn(async move {
+            if let Err(e) = tor_api
+                .expose_onion_service(tor_service_ready, shutdown_signal_tor)
+                .await
+            {
+                eprintln!("Cannot connect to the Tor backend: {e}");
+                std::process::exit(1);
+            }
+        }));
+
+        ready_signal_tor.await
+    }
+
+    log::info!("Tower ready");
     chain_monitor.monitor_chain().await;
 
     // Wait until shutdown
     http_api_task.await.unwrap();
     private_api_task.await.unwrap();
     public_api_task.await.unwrap();
-    log::info!("Shutting down tower")
+    if let Some(tor_task) = tor_task {
+        tor_task.await.unwrap();
+    }
+
+    log::info!("Shutting down tower");
 }

teos/src/test_utils.rs

@@ -8,38 +8,39 @@
 */
 
 use rand::Rng;
-use std::convert::TryInto;
 use std::ops::Deref;
 use std::sync::{Arc, Condvar, Mutex};
 use std::thread;
 
 use jsonrpc_http_server::jsonrpc_core::error::ErrorCode as JsonRpcErrorCode;
 use jsonrpc_http_server::jsonrpc_core::{Error as JsonRpcError, IoHandler, Params, Value};
-use jsonrpc_http_server::{Server, ServerBuilder};
+use jsonrpc_http_server::{CloseHandle, Server, ServerBuilder};
 
 use bitcoincore_rpc::{Auth, Client as BitcoindClient};
 
-use bitcoin::blockdata::block::{Block, BlockHeader};
+use bitcoin::block::Block;
 use bitcoin::blockdata::constants::genesis_block;
-use bitcoin::blockdata::script::{Builder, Script};
+use bitcoin::blockdata::script::{Builder, ScriptBuf};
 use bitcoin::blockdata::transaction::{OutPoint, Transaction, TxIn, TxOut};
 use bitcoin::hash_types::BlockHash;
 use bitcoin::hash_types::Txid;
-use bitcoin::hashes::hex::FromHex;
 use bitcoin::hashes::Hash;
-use bitcoin::network::constants::Network;
-use bitcoin::util::hash::bitcoin_merkle_root;
-use bitcoin::util::psbt::serialize::Deserialize;
-use bitcoin::util::uint::Uint256;
+use bitcoin::merkle_tree::calculate_root;
+use bitcoin::pow::Work;
+use bitcoin::Amount;
+use bitcoin::Network;
+use bitcoin::Witness;
 use lightning_block_sync::poll::{
     ChainPoller, Poll, Validate, ValidatedBlock, ValidatedBlockHeader,
 };
 use lightning_block_sync::{
-    AsyncBlockSourceResult, BlockHeaderData, BlockSource, BlockSourceError, UnboundedCache,
+    AsyncBlockSourceResult, BlockData, BlockHeaderData, BlockSource, BlockSourceError,
+    UnboundedCache,
 };
 
-use teos_common::appointment::{Appointment, Locator};
-use teos_common::cryptography::{encrypt, get_random_bytes, get_random_keypair};
+use teos_common::constants::IRREVOCABLY_RESOLVED;
+use teos_common::cryptography::{get_random_bytes, get_random_keypair};
+use teos_common::test_utils::{generate_random_appointment, get_random_user_id, TXID_HEX, TX_HEX};
 use teos_common::UserId;
 
 use crate::api::internal::InternalAPI;
@@ -47,18 +48,20 @@ use crate::carrier::Carrier;
 use crate::dbm::DBM;
 use crate::extended_appointment::{ExtendedAppointment, UUID};
 use crate::gatekeeper::{Gatekeeper, UserInfo};
+use crate::protos as msgs;
 use crate::responder::{ConfirmationStatus, Responder, TransactionTracker};
+use crate::rpc_errors;
 use crate::watcher::{Breach, Watcher};
 
-pub(crate) static TX_HEX: &str =  "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";
-pub(crate) static TXID_HEX: &str =
-    "338bda693c4a26e0d41a01f7f2887aaf48bf0bdf93e6415c9110b29349349d3e";
-
 pub(crate) const SLOTS: u32 = 21;
 pub(crate) const DURATION: u32 = 500;
 pub(crate) const EXPIRY_DELTA: u32 = 42;
 pub(crate) const START_HEIGHT: usize = 100;
 
+pub(crate) const AVAILABLE_SLOTS: u32 = 21;
+pub(crate) const SUBSCRIPTION_START: u32 = START_HEIGHT as u32;
+pub(crate) const SUBSCRIPTION_EXPIRY: u32 = SUBSCRIPTION_START + 42;
+
 #[derive(Clone, Default, Debug)]
 pub(crate) struct Blockchain {
     pub blocks: Vec<Block>,
@@ -84,23 +87,10 @@ impl Blockchain {
 
     pub fn with_height(mut self, height: usize) -> Self {
         self.blocks.reserve_exact(height);
-        let bits = BlockHeader::compact_target_from_u256(&Uint256::from_be_bytes([0xff; 32]));
-        for i in 1..=height {
-            let prev_block = &self.blocks[i - 1];
-            let prev_blockhash = prev_block.block_hash();
-            let time = prev_block.header.time + height as u32;
-            self.blocks.push(Block {
-                header: BlockHeader {
-                    version: 0,
-                    prev_blockhash,
-                    merkle_root: Default::default(),
-                    time,
-                    bits,
-                    nonce: 0,
-                },
-                txdata: vec![],
-            });
+        for _ in 1..=height {
+            self.generate(None);
         }
+
         self
     }
 
@@ -166,8 +156,11 @@ impl Blockchain {
     fn at_height_unvalidated(&self, height: usize) -> BlockHeaderData {
         assert!(!self.blocks.is_empty());
         assert!(height < self.blocks.len());
+        let height_bytes = height.to_be_bytes();
+        let mut padded_bytes = [0u8; 32];
+        padded_bytes[32 - height_bytes.len()..].copy_from_slice(&height_bytes);
         BlockHeaderData {
-            chainwork: self.blocks[0].header.work() + Uint256::from_u64(height as u64).unwrap(),
+            chainwork: self.blocks[0].header.work() + Work::from_be_bytes(padded_bytes),
             height: height as u32,
             header: self.blocks[height].header,
         }
@@ -197,29 +190,36 @@ impl Blockchain {
     }
 
     pub fn generate(&mut self, txs: Option<Vec<Transaction>>) -> Block {
-        let bits = BlockHeader::compact_target_from_u256(&Uint256::from_be_bytes([0xff; 32]));
+        let bits = bitcoin::Target::from_be_bytes([0xff; 32]).to_compact_lossy();
 
         let prev_block = self.blocks.last().unwrap();
         let prev_blockhash = prev_block.block_hash();
         let time = prev_block.header.time + (self.blocks.len() + 1) as u32;
         let txdata = match txs {
-            Some(t) => t,
-            None => vec![],
+            Some(v) => {
+                if v.is_empty() {
+                    vec![get_random_tx()]
+                } else {
+                    v
+                }
+            }
+            None => vec![get_random_tx()],
         };
-        let hashes = txdata.iter().map(|obj| obj.txid().as_hash());
-
-        let block = Block {
-            header: BlockHeader {
-                version: 0,
-                prev_blockhash,
-                merkle_root: bitcoin_merkle_root(hashes).into(),
-                time,
-                bits,
-                nonce: 0,
-            },
-            txdata,
+        let hashes = txdata.iter().map(|tx| tx.compute_txid().to_raw_hash());
+        let mut header = bitcoin::block::Header {
+            version: bitcoin::block::Version::from_consensus(0),
+            prev_blockhash,
+            merkle_root: calculate_root(hashes).unwrap().into(),
+            time,
+            bits,
+            nonce: 0,
         };
 
+        while header.validate_pow(header.target()).is_err() {
+            header.nonce += 1;
+        }
+
+        let block = Block { header, txdata };
         self.blocks.push(block.clone());
 
         block
@@ -228,7 +228,7 @@ impl Blockchain {
 
 impl BlockSource for Blockchain {
     fn get_header<'a>(
-        &'a mut self,
+        &'a self,
         header_hash: &'a BlockHash,
         _height_hint: Option<u32>,
     ) -> AsyncBlockSourceResult<'a, BlockHeaderData> {
@@ -251,10 +251,7 @@ impl BlockSource for Blockchain {
         })
     }
 
-    fn get_block<'a>(
-        &'a mut self,
-        header_hash: &'a BlockHash,
-    ) -> AsyncBlockSourceResult<'a, Block> {
+    fn get_block<'a>(&'a self, header_hash: &'a BlockHash) -> AsyncBlockSourceResult<BlockData> {
         Box::pin(async move {
             for (height, block) in self.blocks.iter().enumerate() {
                 if block.header.block_hash() == *header_hash {
@@ -263,15 +260,14 @@ impl BlockSource for Blockchain {
                             return Err(BlockSourceError::persistent("block not found"));
                         }
                     }
-
-                    return Ok(block.clone());
+                    return Ok(BlockData::FullBlock(block.clone()));
                 }
             }
             Err(BlockSourceError::transient("block not found"))
         })
     }
 
-    fn get_best_block(&mut self) -> AsyncBlockSourceResult<(BlockHash, Option<u32>)> {
+    fn get_best_block(&self) -> AsyncBlockSourceResult<(BlockHash, Option<u32>)> {
         Box::pin(async move {
             if *self.unreachable.lock().unwrap() {
                 return Err(BlockSourceError::transient("Connection refused"));
@@ -290,13 +286,7 @@ impl BlockSource for Blockchain {
 pub(crate) fn generate_uuid() -> UUID {
     let mut rng = rand::thread_rng();
 
-    UUID::deserialize(&rng.gen::<[u8; 20]>()).unwrap()
-}
-
-pub(crate) fn get_random_user_id() -> UserId {
-    let (_, pk) = get_random_keypair();
-
-    UserId(pk)
+    UUID::from_slice(&rng.gen::<[u8; 20]>()).unwrap()
 }
 
 pub(crate) fn get_random_tx() -> Transaction {
@@ -304,42 +294,26 @@ pub(crate) fn get_random_tx() -> Transaction {
     let prev_txid_bytes = get_random_bytes(32);
 
     Transaction {
-        version: 2,
-        lock_time: 0,
+        version: bitcoin::transaction::Version(2),
+        lock_time: bitcoin::locktime::absolute::LockTime::from_height(0).unwrap(),
         input: vec![TxIn {
             previous_output: OutPoint::new(
                 Txid::from_slice(&prev_txid_bytes).unwrap(),
                 rng.gen_range(0..200),
             ),
-            script_sig: Script::new(),
-            witness: Vec::new(),
-            sequence: 0,
+            script_sig: ScriptBuf::new(),
+            witness: Witness::new(),
+            sequence: bitcoin::Sequence(0),
         }],
         output: vec![TxOut {
             script_pubkey: Builder::new().push_int(1).into_script(),
-            value: rng.gen_range(0..21000000000),
+            value: Amount::from_sat(rng.gen_range(0..21_000_000_000)),
         }],
     }
 }
 
 pub(crate) fn generate_dummy_appointment(dispute_txid: Option<&Txid>) -> ExtendedAppointment {
-    let dispute_txid = match dispute_txid {
-        Some(l) => *l,
-        None => {
-            let prev_txid_bytes = get_random_bytes(32);
-            Txid::from_slice(&prev_txid_bytes).unwrap()
-        }
-    };
-
-    let tx_bytes = Vec::from_hex(TX_HEX).unwrap();
-    let penalty_tx = Transaction::deserialize(&tx_bytes).unwrap();
-
-    let mut raw_locator: [u8; 16] = get_random_bytes(16).try_into().unwrap();
-    raw_locator.copy_from_slice(&dispute_txid[..16]);
-    let locator = Locator::deserialize(&raw_locator).unwrap();
-
-    let encrypted_blob = encrypt(&penalty_tx, &dispute_txid).unwrap();
-    let appointment = Appointment::new(locator, encrypted_blob, 21);
+    let appointment = generate_random_appointment(dispute_txid);
     let user_id = get_random_user_id();
     let user_signature = String::new();
     let start_block = 42;
@@ -354,7 +328,7 @@ pub(crate) fn generate_dummy_appointment_with_user(
     let mut app = generate_dummy_appointment(dispute_txid);
     app.user_id = user_id;
 
-    (UUID::new(app.locator(), user_id), app)
+    (app.uuid(), app)
 }
 
 pub(crate) fn get_random_breach() -> Breach {
@@ -372,62 +346,82 @@ pub(crate) fn get_random_tracker(
     TransactionTracker::new(breach, user_id, status)
 }
 
-pub(crate) fn store_appointment_and_fks_to_db(
-    dbm: &DBM,
-    uuid: UUID,
-    appointment: &ExtendedAppointment,
-) {
-    dbm.store_user(appointment.user_id, &UserInfo::new(21, 42))
+pub(crate) fn store_appointment_and_its_user(dbm: &DBM, appointment: &ExtendedAppointment) {
+    dbm.store_user(
+        appointment.user_id,
+        &UserInfo::new(AVAILABLE_SLOTS, SUBSCRIPTION_START, SUBSCRIPTION_EXPIRY),
+    )
+    // It's ok if the user is already stored.
+    .ok();
+    dbm.store_appointment(appointment.uuid(), appointment)
         .unwrap();
-    dbm.store_appointment(uuid, appointment).unwrap();
 }
 
 pub(crate) async fn get_last_n_blocks(chain: &mut Blockchain, n: usize) -> Vec<ValidatedBlock> {
-    let tip = chain.tip();
-    let mut poller = ChainPoller::new(chain, Network::Bitcoin);
+    let mut last_n_blocks = Vec::with_capacity(n);
+    let mut last_known_block = Ok(chain.tip());
+    let poller = ChainPoller::new(chain, Network::Regtest);
 
-    let mut last_n_blocks = Vec::new();
-    let mut last_known_block = tip;
     for _ in 0..n {
-        let block = poller.fetch_block(&last_known_block).await.unwrap();
-        last_known_block = poller
-            .look_up_previous_header(&last_known_block)
-            .await
-            .unwrap();
+        let header = last_known_block.unwrap();
+        let block = poller.fetch_block(&header).await.unwrap();
         last_n_blocks.push(block);
+        last_known_block = poller.look_up_previous_header(&header).await;
     }
 
     last_n_blocks
 }
 
+pub(crate) fn get_full_blocks(last_n_blocks: &[ValidatedBlock]) -> Vec<Block> {
+    last_n_blocks.iter().map(get_full_block).collect()
+}
+
+pub(crate) fn get_full_block(block: &ValidatedBlock) -> Block {
+    match block.deref() {
+        BlockData::FullBlock(b) => b.clone(),
+        _ => panic!("Expected FullBlock"),
+    }
+}
+
 pub(crate) enum MockedServerQuery {
     Regular,
+    InMempoool,
     Error(i64),
 }
 
-pub(crate) fn create_carrier(query: MockedServerQuery, height: u32) -> Carrier {
+pub(crate) fn create_carrier(query: MockedServerQuery, height: u32) -> (Carrier, BitcoindStopper) {
     let bitcoind_mock = match query {
-        MockedServerQuery::Regular => BitcoindMock::new(MockOptions::empty()),
+        MockedServerQuery::Regular => BitcoindMock::new(MockOptions::default()),
+        MockedServerQuery::InMempoool => BitcoindMock::new(MockOptions::in_mempool()),
         MockedServerQuery::Error(x) => BitcoindMock::new(MockOptions::with_error(x)),
     };
     let bitcoin_cli = Arc::new(BitcoindClient::new(bitcoind_mock.url(), Auth::None).unwrap());
     let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
-    start_server(bitcoind_mock);
+    start_server(bitcoind_mock.server);
 
-    Carrier::new(bitcoin_cli, bitcoind_reachable, height)
+    (
+        Carrier::new(bitcoin_cli, bitcoind_reachable, height),
+        bitcoind_mock.stopper,
+    )
 }
 
-pub(crate) fn create_responder(
-    tip: ValidatedBlockHeader,
+pub(crate) async fn create_responder(
+    chain: &mut Blockchain,
     gatekeeper: Arc<Gatekeeper>,
     dbm: Arc<Mutex<DBM>>,
     server_url: &str,
 ) -> Responder {
+    let height = chain.tip().height;
+    // For the local TxIndex logic to be sound, our index needs to have, at least, IRREVOCABLY_RESOLVED blocks
+    debug_assert!(height >= IRREVOCABLY_RESOLVED);
+
+    let last_n_blocks = get_last_n_blocks(chain, IRREVOCABLY_RESOLVED as usize).await;
+
     let bitcoin_cli = Arc::new(BitcoindClient::new(server_url, Auth::None).unwrap());
     let bitcoind_reachable = Arc::new((Mutex::new(true), Condvar::new()));
-    let carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, tip.deref().height);
+    let carrier = Carrier::new(bitcoin_cli, bitcoind_reachable, height);
 
-    Responder::new(carrier, gatekeeper, dbm)
+    Responder::new(last_n_blocks.as_slice(), height, carrier, gatekeeper, dbm)
 }
 
 pub(crate) async fn create_watcher(
@@ -436,20 +430,23 @@ pub(crate) async fn create_watcher(
     gatekeeper: Arc<Gatekeeper>,
     bitcoind_mock: BitcoindMock,
     dbm: Arc<Mutex<DBM>>,
-) -> Watcher {
+) -> (Watcher, BitcoindStopper) {
     let last_n_blocks = get_last_n_blocks(chain, 6).await;
 
-    start_server(bitcoind_mock);
+    start_server(bitcoind_mock.server);
     let (tower_sk, tower_pk) = get_random_keypair();
     let tower_id = UserId(tower_pk);
-    Watcher::new(
-        gatekeeper,
-        responder,
-        last_n_blocks,
-        chain.get_block_count(),
-        tower_sk,
-        tower_id,
-        dbm,
+    (
+        Watcher::new(
+            gatekeeper,
+            responder,
+            last_n_blocks.as_slice(),
+            chain.get_block_count(),
+            tower_sk,
+            tower_id,
+            dbm,
+        ),
+        bitcoind_mock.stopper,
     )
 }
 #[derive(Clone)]
@@ -484,8 +481,10 @@ impl Default for ApiConfig {
     }
 }
 
-pub(crate) async fn create_api_with_config(api_config: ApiConfig) -> Arc<InternalAPI> {
-    let bitcoind_mock = BitcoindMock::new(MockOptions::empty());
+pub(crate) async fn create_api_with_config(
+    api_config: ApiConfig,
+) -> (Arc<InternalAPI>, BitcoindStopper) {
+    let bitcoind_mock = BitcoindMock::new(MockOptions::default());
     let mut chain = Blockchain::default().with_height(START_HEIGHT);
 
     let dbm = Arc::new(Mutex::new(DBM::in_memory().unwrap()));
@@ -496,8 +495,9 @@ pub(crate) async fn create_api_with_config(api_config: ApiConfig) -> Arc<Interna
         EXPIRY_DELTA,
         dbm.clone(),
     ));
-    let responder = create_responder(chain.tip(), gk.clone(), dbm.clone(), bitcoind_mock.url());
-    let watcher = create_watcher(
+    let responder =
+        create_responder(&mut chain, gk.clone(), dbm.clone(), bitcoind_mock.url()).await;
+    let (watcher, stopper) = create_watcher(
         &mut chain,
         Arc::new(responder),
         gk.clone(),
@@ -508,58 +508,66 @@ pub(crate) async fn create_api_with_config(api_config: ApiConfig) -> Arc<Interna
 
     let bitcoind_reachable = Arc::new((Mutex::new(api_config.bitcoind_reachable), Condvar::new()));
     let (shutdown_trigger, _) = triggered::trigger();
-    Arc::new(InternalAPI::new(
-        Arc::new(watcher),
-        bitcoind_reachable,
-        shutdown_trigger,
-    ))
+    (
+        Arc::new(InternalAPI::new(
+            Arc::new(watcher),
+            vec![msgs::NetworkAddress::from_ipv4("address".to_string(), 21)],
+            bitcoind_reachable,
+            shutdown_trigger,
+        )),
+        stopper,
+    )
 }
 
-pub(crate) async fn create_api() -> Arc<InternalAPI> {
+pub(crate) async fn create_api() -> (Arc<InternalAPI>, BitcoindStopper) {
     create_api_with_config(ApiConfig::default()).await
 }
+
+#[derive(Clone)]
+pub struct BitcoindStopper {
+    close_handle: CloseHandle,
+}
+
+impl BitcoindStopper {
+    pub fn new(close_handle: CloseHandle) -> Self {
+        Self { close_handle }
+    }
+
+    pub fn close_handle(&self) -> CloseHandle {
+        self.close_handle.clone()
+    }
+}
+
+impl Drop for BitcoindStopper {
+    fn drop(&mut self) {
+        self.close_handle().close()
+    }
+}
+
 pub(crate) struct BitcoindMock {
     pub url: String,
     pub server: Server,
+    stopper: BitcoindStopper,
 }
 
+#[derive(Default)]
 pub(crate) struct MockOptions {
     error_code: Option<i64>,
-    block_hash: Option<BlockHash>,
-    height: Option<usize>,
+    in_mempool: bool,
 }
 
 impl MockOptions {
-    pub fn new(error_code: i64, block_hash: BlockHash, height: usize) -> Self {
-        Self {
-            error_code: Some(error_code),
-            block_hash: Some(block_hash),
-            height: Some(height),
-        }
-    }
-
-    pub fn empty() -> Self {
-        Self {
-            error_code: None,
-            block_hash: None,
-            height: None,
-        }
-    }
-
     pub fn with_error(error_code: i64) -> Self {
         Self {
             error_code: Some(error_code),
-            block_hash: None,
-            height: None,
+            in_mempool: false,
         }
     }
 
-    #[allow(dead_code)]
-    pub fn with_block(block_hash: BlockHash, height: usize) -> Self {
+    pub fn in_mempool() -> Self {
         Self {
             error_code: None,
-            block_hash: Some(block_hash),
-            height: Some(height),
+            in_mempool: true,
         }
     }
 }
@@ -573,15 +581,10 @@ impl BitcoindMock {
                 Err(JsonRpcError::new(JsonRpcErrorCode::ServerError(error)))
             });
             io.add_alias("sendrawtransaction", "error");
+            io.add_alias("getrawtransaction", "error");
         } else {
             BitcoindMock::add_sendrawtransaction(&mut io);
-        }
-
-        if let Some(block_hash) = options.block_hash {
-            BitcoindMock::add_getrawtransaction(&mut io, block_hash.to_string());
-            if let Some(height) = options.height {
-                BitcoindMock::add_getblockheader(&mut io, block_hash.to_string(), height);
-            }
+            BitcoindMock::add_getrawtransaction(&mut io, options.in_mempool);
         }
 
         let server = ServerBuilder::new(io)
@@ -591,6 +594,7 @@ impl BitcoindMock {
 
         Self {
             url: format!("http://{}", server.address()),
+            stopper: BitcoindStopper::new(server.close_handle()),
             server,
         }
     }
@@ -601,41 +605,25 @@ impl BitcoindMock {
         });
     }
 
-    fn add_getrawtransaction(io: &mut IoHandler, block_hash: String) {
+    fn add_getrawtransaction(io: &mut IoHandler, in_mempool: bool) {
         io.add_sync_method("getrawtransaction", move |_params: Params|  {
-            match _params {
-                Params::Array(x) => match x[1] {
-                    Value::Bool(x) => {
-                        if x {
-                            Ok(serde_json::json!({"hex": TX_HEX, "txid": TXID_HEX, "hash": TXID_HEX, "size": 0, 
-                            "vsize": 0, "version": 1, "locktime": 0, "vin": [], "vout": [], "blockhash": block_hash }))
-                        } else {
-                            Ok(Value::String(TX_HEX.to_owned()))
+            if !in_mempool {
+                Err(JsonRpcError::new(JsonRpcErrorCode::ServerError(rpc_errors::RPC_INVALID_ADDRESS_OR_KEY as i64)))
+            } else {
+                match _params {
+                    Params::Array(x) => match x[1] {
+                        Value::Bool(x) => {
+                            if x {
+                                Ok(serde_json::json!({"hex": TX_HEX, "txid": TXID_HEX, "hash": TXID_HEX, "size": 0, 
+                                "vsize": 0, "version": 1, "locktime": 0, "vin": [], "vout": [] }))
+                            } else {
+                                Ok(Value::String(TX_HEX.to_owned()))
+                            }
                         }
-                    }
-                    _ => panic!("Boolean param not found"),
-                },
-                _ => panic!("No params found"),
-            }
-        })
-    }
-
-    fn add_getblockheader(io: &mut IoHandler, block_hash: String, height: usize) {
-        io.add_sync_method("getblockheader", move |_params: Params|  {
-            match _params {
-                Params::Array(x) => match x[1] {
-                    Value::Bool(x) => {
-                        if x {
-                            Ok(serde_json::json!({"hash": block_hash, "confirmations": 1, "height": height, "version": 1, 
-                            "merkleroot": "4eca41cf0fa551346842eb317564a403e39553444790a65f949f95bc18d24643", "time": 1645719068, "nonce": 2, "bits": "207fffff", 
-                            "difficulty": 0.0, "chainwork": "0000000000000000000000000000000000000000000000000000000000001146", "nTx": 1}))
-                        } else {
-                            Ok(Value::String(TX_HEX.to_owned()))
-                        }
-                    }
-                    _ => panic!("Boolean param not found"),
-                },
-                _ => panic!("No params found"),
+                        _ => panic!("Boolean param not found"),
+                    },
+                    _ => panic!("No params found"),
+                }
             }
         })
     }
@@ -645,8 +633,8 @@ impl BitcoindMock {
     }
 }
 
-pub(crate) fn start_server(bitcoind: BitcoindMock) {
+pub(crate) fn start_server(server: Server) {
     thread::spawn(move || {
-        bitcoind.server.wait();
+        server.wait();
     });
 }

teos/src/tls.rs

@@ -0,0 +1,105 @@
+/* The following code for generating mTLS certificates is adapted from:
+ * https://github.com/ElementsProject/lightning/blob/master/plugins/grpc-plugin/src/tls.rs
+ *
+ * This file is licensed under the BSD-MIT license, as described here:
+ * https://github.com/ElementsProject/lightning/blob/master/LICENSE
+*/
+
+use rcgen::{Certificate, Error as RcgenError, KeyPair};
+use std::convert::TryFrom;
+use std::path::Path;
+
+/// Packs the reasons why generating mtls certificates may fail.
+#[derive(Debug)]
+pub enum GenCertificateFailure {
+    RcgenError(RcgenError),
+    IoError(std::io::Error),
+}
+
+impl From<RcgenError> for GenCertificateFailure {
+    fn from(e: RcgenError) -> Self {
+        GenCertificateFailure::RcgenError(e)
+    }
+}
+
+impl From<std::io::Error> for GenCertificateFailure {
+    fn from(e: std::io::Error) -> Self {
+        GenCertificateFailure::IoError(e)
+    }
+}
+
+/// Just a wrapper around a certificate and an associated keypair.
+#[derive(Clone, Debug)]
+struct Identity {
+    pub key: Vec<u8>,
+    pub certificate: Vec<u8>,
+}
+
+impl TryFrom<&Identity> for (Certificate, KeyPair) {
+    type Error = RcgenError;
+
+    fn try_from(id: &Identity) -> Result<(Certificate, KeyPair), RcgenError> {
+        let key = KeyPair::from_pem(&String::from_utf8_lossy(&id.key))?;
+        let params =
+            rcgen::CertificateParams::from_ca_cert_pem(&String::from_utf8_lossy(&id.certificate))?;
+        let cert = params.self_signed(&key)?;
+        Ok((cert, key))
+    }
+}
+
+pub fn tls_init(
+    directory: &Path,
+) -> Result<(tonic::transport::Identity, Vec<u8>), GenCertificateFailure> {
+    let ca = generate_or_load_identity("teos Root CA", directory, "ca", None)?;
+    let server = generate_or_load_identity("teos grpc Server", directory, "server", Some(&ca))?;
+    let _client = generate_or_load_identity("teos grpc Client", directory, "client", Some(&ca))?;
+    let server_id = tonic::transport::Identity::from_pem(&server.certificate, &server.key);
+
+    Ok((server_id, ca.certificate))
+}
+
+/// Generate a given identity
+fn generate_or_load_identity(
+    name: &str,
+    directory: &Path,
+    filename: &str,
+    parent: Option<&Identity>,
+) -> Result<Identity, GenCertificateFailure> {
+    // Just our naming convention here.
+    let cert_path = directory.join(format!("{filename}.pem"));
+    let key_path = directory.join(format!("{filename}-key.pem"));
+    // Did we have to generate a new key? In that case we also need to regenerate the certificate.
+    if !key_path.exists() || !cert_path.exists() {
+        log::debug!("Generating a new keypair in {key_path:?}, it didn't exist",);
+        let keypair = KeyPair::generate()?;
+        std::fs::write(&key_path, keypair.serialize_pem())?;
+        log::debug!("Generating a new certificate for key {key_path:?} at {cert_path:?}",);
+
+        // Configure the certificate we want.
+        let subject_alt_names = vec!["teos".to_string(), "localhost".to_string()];
+        let mut params = rcgen::CertificateParams::new(subject_alt_names)?;
+        if parent.is_none() {
+            params.is_ca = rcgen::IsCa::Ca(rcgen::BasicConstraints::Unconstrained);
+        } else {
+            params.is_ca = rcgen::IsCa::NoCa;
+        }
+        params
+            .distinguished_name
+            .push(rcgen::DnType::CommonName, name);
+
+        std::fs::write(
+            &cert_path,
+            match parent {
+                None => params.self_signed(&keypair)?.pem(),
+                Some(ca) => {
+                    let (ca_cert, ca_key) = <(Certificate, KeyPair)>::try_from(ca)?;
+                    params.signed_by(&keypair, &ca_cert, &ca_key)?.pem()
+                }
+            },
+        )?;
+    }
+
+    let key = std::fs::read(&key_path)?;
+    let certificate = std::fs::read(cert_path)?;
+    Ok(Identity { certificate, key })
+}

teos/src/tx_index.rs

@@ -0,0 +1,418 @@
+use std::collections::{HashMap, VecDeque};
+use std::fmt;
+use std::hash::Hash;
+use std::ops::Deref;
+
+use bitcoin::block::Header;
+use bitcoin::hash_types::BlockHash;
+use bitcoin::{Transaction, Txid};
+use lightning_block_sync::poll::ValidatedBlock;
+
+use teos_common::appointment::Locator;
+
+/// A trait implemented by types that can be used as key in a [TxIndex].
+pub trait Key: Hash + Eq {
+    fn from_txid(txid: Txid) -> Self;
+}
+
+impl Key for Txid {
+    fn from_txid(txid: Txid) -> Self {
+        txid
+    }
+}
+
+impl Key for Locator {
+    fn from_txid(txid: Txid) -> Self {
+        Locator::new(txid)
+    }
+}
+
+pub enum Type {
+    Transaction,
+    BlockHash,
+}
+
+pub enum Data {
+    Transaction(Transaction),
+    BlockHash(BlockHash),
+}
+
+impl fmt::Display for Data {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Data::Transaction(_) => write!(f, "Transaction"),
+            Data::BlockHash(_) => write!(f, "BlockHash"),
+        }
+    }
+}
+
+/// A trait implemented by types that can be used as value in a [TxIndex].
+pub trait Value {
+    fn get_type() -> Type;
+    fn from_data(d: Data) -> Self;
+}
+
+impl Value for BlockHash {
+    fn get_type() -> Type {
+        Type::BlockHash
+    }
+
+    fn from_data(d: Data) -> Self {
+        match d {
+            Data::BlockHash(b) => b,
+            other => panic!("Cannot build a BlockHash from {}", other),
+        }
+    }
+}
+
+impl Value for Transaction {
+    fn get_type() -> Type {
+        Type::Transaction
+    }
+
+    fn from_data(d: Data) -> Self {
+        match d {
+            Data::Transaction(t) => t,
+            other => panic!("Cannot build a BlockHash from {}", other),
+        }
+    }
+}
+
+/// Data structure used to index locators computed from parsed blocks.
+///
+/// Holds up to `size` blocks with their corresponding computed [Locator]s.
+#[derive(Debug, PartialEq, Eq)]
+pub struct TxIndex<K: Key, V: Value> {
+    /// A [K]:[V] map.
+    index: HashMap<K, V>,
+    /// Vector of block hashes covered by the index.
+    blocks: VecDeque<BlockHash>,
+    /// Map of [BlockHash]:[Vec<K>]. Used to remove data from the index.
+    tx_in_block: HashMap<BlockHash, Vec<K>>,
+    /// The height of the last block included in the index.
+    tip: u32,
+    /// Maximum size of the index.
+    size: usize,
+}
+
+impl<K, V> TxIndex<K, V>
+where
+    K: Key + Copy,
+    V: Value + Clone,
+    Self: Sized,
+{
+    pub fn new(last_n_blocks: &[ValidatedBlock], height: u32) -> Self {
+        let size = last_n_blocks.len();
+        let mut tx_index = Self {
+            index: HashMap::new(),
+            blocks: VecDeque::with_capacity(size),
+            tx_in_block: HashMap::new(),
+            tip: height,
+            size,
+        };
+
+        for block in last_n_blocks.iter().rev() {
+            match block.deref() {
+                lightning_block_sync::BlockData::HeaderOnly(_) => {
+                    panic!("Expected FullBlock")
+                }
+                lightning_block_sync::BlockData::FullBlock(block) => {
+                    if let Some(prev_block_hash) = tx_index.blocks.back() {
+                        if block.header.prev_blockhash != *prev_block_hash {
+                            panic!("last_n_blocks contains unchained blocks");
+                        }
+                    };
+
+                    let map = block
+                        .txdata
+                        .iter()
+                        .map(|tx| {
+                            (
+                                K::from_txid(tx.compute_txid()),
+                                match V::get_type() {
+                                    Type::Transaction => {
+                                        V::from_data(Data::Transaction(tx.clone()))
+                                    }
+                                    Type::BlockHash => {
+                                        V::from_data(Data::BlockHash(block.header.block_hash()))
+                                    }
+                                },
+                            )
+                        })
+                        .collect();
+
+                    tx_index.update(block.header, &map);
+                }
+            }
+        }
+
+        tx_index
+    }
+
+    /// Gets an item from the index if present. [None] otherwise.
+    pub fn get<'a>(&'a self, k: &'a K) -> Option<&V> {
+        self.index.get(k)
+    }
+
+    /// Checks if the index if full.
+    pub fn is_full(&self) -> bool {
+        self.blocks.len() > self.size
+    }
+
+    /// Get's the height of a given block based on its position in the block queue.
+    pub fn get_height(&self, block_hash: &BlockHash) -> Option<usize> {
+        let pos = self.blocks.iter().position(|x| x == block_hash)?;
+        Some(self.tip as usize + pos + 1 - self.blocks.len())
+    }
+
+    /// Updates the index by adding data from a new block. Removes the oldest block if the index is full afterwards.
+    pub fn update(&mut self, block_header: Header, data: &HashMap<K, V>) {
+        self.blocks.push_back(block_header.block_hash());
+
+        let ks = data
+            .iter()
+            .map(|(k, v)| {
+                self.index.insert(*k, v.clone());
+                *k
+            })
+            .collect();
+
+        self.tx_in_block.insert(block_header.block_hash(), ks);
+
+        if self.is_full() {
+            // Avoid logging during bootstrap
+            log::debug!("New block added to index: {}", block_header.block_hash());
+            self.tip += 1;
+            self.remove_oldest_block();
+        }
+    }
+
+    /// Fixes the index by removing disconnected data.
+    pub fn remove_disconnected_block(&mut self, block_hash: &BlockHash) {
+        if let Some(ks) = self.tx_in_block.remove(block_hash) {
+            self.index.retain(|k, _| !ks.contains(k));
+
+            // Blocks should be disconnected from last backwards. Log if that's not the case so we can revisit this and fix it.
+            if let Some(ref h) = self.blocks.pop_back() {
+                if h != block_hash {
+                    log::error!("Disconnected block does not match the oldest block stored in the TxIndex ({block_hash} != {h})");
+                }
+            }
+        } else {
+            log::warn!("The index is already empty");
+        }
+    }
+
+    /// Removes the oldest block from the index.
+    /// This removes data from `self.blocks`, `self.tx_in_block` and `self.index`.
+    pub fn remove_oldest_block(&mut self) {
+        let h = self.blocks.pop_front().unwrap();
+        let ks = self.tx_in_block.remove(&h).unwrap();
+        self.index.retain(|k, _| !ks.contains(k));
+
+        log::debug!("Oldest block removed from index: {h}");
+    }
+}
+
+impl<K: std::fmt::Debug + Key, V: std::fmt::Debug + Value> fmt::Display for TxIndex<K, V> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(
+            f,
+            "index: {:?}\n\nblocks: {:?}\n\ntx_in_block: {:?}\n\nsize: {}",
+            self.index, self.blocks, self.tx_in_block, self.size
+        )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::ops::Deref;
+
+    use crate::test_utils::{get_full_block, get_full_blocks, get_last_n_blocks, Blockchain};
+
+    use bitcoin::hashes::serde_macros::serde_details::SerdeHash;
+    use bitcoin::Block;
+
+    impl<K, V> TxIndex<K, V>
+    where
+        K: Key + std::cmp::Eq + Copy,
+        V: Value + Clone,
+        Self: Sized,
+    {
+        pub fn index_mut(&mut self) -> &mut HashMap<K, V> {
+            &mut self.index
+        }
+
+        pub fn blocks(&self) -> &VecDeque<BlockHash> {
+            &self.blocks
+        }
+
+        pub fn contains_key(&self, k: &K) -> bool {
+            self.index.contains_key(k)
+        }
+    }
+
+    #[tokio::test]
+    async fn test_new() {
+        let height = 10;
+        let mut chain = Blockchain::default().with_height(height as usize);
+        let last_six_blocks = get_last_n_blocks(&mut chain, 6).await;
+        let blocks: Vec<Block> = get_full_blocks(&last_six_blocks);
+
+        let cache: TxIndex<Locator, Transaction> = TxIndex::new(&last_six_blocks, height);
+        assert_eq!(blocks.len(), cache.size);
+        for block in blocks.iter() {
+            assert!(cache.blocks().contains(&block.block_hash()));
+
+            let mut locators = Vec::new();
+            for tx in block.txdata.iter() {
+                let locator = Locator::new(tx.compute_txid());
+                assert!(cache.contains_key(&locator));
+                locators.push(locator);
+            }
+
+            assert_eq!(cache.tx_in_block[&block.block_hash()], locators);
+        }
+    }
+
+    #[tokio::test]
+    async fn test_get_height() {
+        let cache_size = 10;
+        let height = 50;
+        let mut chain = Blockchain::default().with_height_and_txs(height, 42);
+        let last_n_blocks = get_last_n_blocks(&mut chain, cache_size).await;
+
+        // last_n_blocks is ordered from latest to earliest
+        let first_block = get_full_block(last_n_blocks.get(cache_size - 1).unwrap());
+        let last_block = get_full_block(last_n_blocks.first().unwrap());
+        let mid_block = get_full_block(last_n_blocks.get(cache_size / 2).unwrap());
+
+        let cache: TxIndex<Locator, Transaction> = TxIndex::new(&last_n_blocks, height as u32);
+
+        assert_eq!(
+            cache.get_height(&first_block.header.block_hash()).unwrap(),
+            height - cache_size + 1
+        );
+        assert_eq!(
+            cache.get_height(&last_block.header.block_hash()).unwrap(),
+            height
+        );
+        assert_eq!(
+            cache.get_height(&mid_block.header.block_hash()).unwrap(),
+            height - cache_size / 2
+        );
+    }
+
+    #[tokio::test]
+    async fn test_get_height_not_found() {
+        let cache_size = 10;
+        let height = 50;
+        let mut chain = Blockchain::default().with_height_and_txs(height, 42);
+        let cache: TxIndex<Locator, Transaction> = TxIndex::new(
+            &get_last_n_blocks(&mut chain, cache_size).await,
+            height as u32,
+        );
+
+        let fake_hash = &BlockHash::from_slice_delegated(&[0; 32]).unwrap();
+        assert!(cache.get_height(fake_hash).is_none());
+    }
+
+    #[tokio::test]
+    async fn test_update() {
+        let height = 10;
+        let mut chain = Blockchain::default().with_height(height as usize);
+        let mut last_n_blocks = get_last_n_blocks(&mut chain, 7).await;
+
+        // Store the last block to use it for an update and the first to check eviction
+        // Notice that the list of blocks is ordered from last to first.
+        let last_block = last_n_blocks.remove(0);
+        let first_block = last_n_blocks.last().unwrap();
+
+        // Init the cache with the 6 block before the last
+        let mut cache = TxIndex::new(&last_n_blocks, height);
+
+        // Update the cache with the last block
+        let full_block = get_full_block(&last_block);
+        let locator_tx_map = full_block
+            .txdata
+            .iter()
+            .map(|tx| (Locator::new(tx.compute_txid()), tx.clone()))
+            .collect();
+
+        let header = full_block.header;
+        cache.update(header, &locator_tx_map);
+
+        // Check that the new data is in the cache
+        assert!(cache.blocks().contains(&header.block_hash()));
+
+        for (locator, _) in locator_tx_map.iter() {
+            assert!(cache.contains_key(locator));
+        }
+
+        let block_hash = full_block.header.block_hash();
+        assert_eq!(
+            cache.tx_in_block[&block_hash],
+            locator_tx_map.keys().cloned().collect::<Vec<Locator>>()
+        );
+
+        // Check that the data from the first block has been evicted
+        let first_full_block = get_full_block(first_block);
+        let tx = first_full_block.txdata[0].clone();
+        assert!(!cache.contains_key(&Locator::new(tx.compute_txid())));
+
+        let block_hash = first_full_block.header.block_hash();
+        assert!(!cache.tx_in_block.contains_key(&block_hash));
+    }
+
+    #[tokio::test]
+    async fn test_remove_disconnected_block() {
+        let cache_size = 6;
+        let height = cache_size * 2;
+        let mut chain = Blockchain::default().with_height_and_txs(height, 42);
+        let mut cache: TxIndex<Locator, Transaction> = TxIndex::new(
+            &get_last_n_blocks(&mut chain, cache_size).await,
+            height as u32,
+        );
+
+        // TxIndex::fix removes the last connected block and removes all the associated data
+        for i in 0..cache_size {
+            let header = chain
+                .at_height(chain.get_block_count() as usize - i)
+                .deref()
+                .header;
+            let locators = cache.tx_in_block.get(&header.block_hash()).unwrap().clone();
+
+            // Make sure there's data regarding the target block in the cache before fixing it
+            assert_eq!(cache.blocks().len(), cache.size - i);
+            assert!(cache.blocks().contains(&header.block_hash()));
+            assert!(!locators.is_empty());
+            for locator in locators.iter() {
+                assert!(cache.contains_key(locator));
+            }
+
+            cache.remove_disconnected_block(&header.block_hash());
+
+            // Check that the block data is not in the cache anymore
+            assert_eq!(cache.blocks().len(), cache.size - i - 1);
+            assert!(!cache.blocks().contains(&header.block_hash()));
+            assert!(!cache.tx_in_block.contains_key(&header.block_hash()));
+            for locator in locators.iter() {
+                assert!(!cache.contains_key(locator));
+            }
+        }
+
+        // At this point the cache should be empty, fixing it further shouldn't do anything
+        for i in cache_size..cache_size * 2 {
+            assert!(cache.index.is_empty());
+            assert!(cache.blocks().is_empty());
+            assert!(cache.tx_in_block.is_empty());
+
+            let header = chain
+                .at_height(chain.get_block_count() as usize - i)
+                .deref()
+                .header;
+            cache.remove_disconnected_block(&header.block_hash());
+        }
+    }
+}

watchtower-plugin/Cargo.toml

@@ -0,0 +1,36 @@
+[package]
+name = "watchtower-plugin"
+version = "0.2.0"
+authors = ["Sergi Delgado Segura <sergi.delgado.s@gmail.com>"]
+license = "MIT"
+edition = "2021"
+
+[[bin]]
+name = "watchtower-client"
+path = "src/main.rs"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+# General
+backoff = { version = "0.4.0", features = ["tokio"] }
+hex = { version = "0.4.3", features = [ "serde" ] }
+home = "0.5.3"
+reqwest = { version = "0.11", features = [ "blocking", "json", "socks" ] }
+log = "0.4.16"
+rusqlite = { version = "0.26.0", features = [ "bundled", "limits" ] }
+serde = "1.0.130"
+serde_json = { version = "1.0", features = [ "preserve_order" ] }
+tonic = { version = "0.11", features = [ "tls", "transport" ] }
+tokio = { version = "1.5", features = [ "rt-multi-thread", "fs" ] }
+
+# Bitcoin and Lightning
+bitcoin = "0.32.0"
+cln-plugin = "0.3.0"
+
+# Local
+teos-common = { path = "../teos-common" }
+
+[dev-dependencies]
+mockito = "0.32.4"
+tempdir = "0.3.7"

watchtower-plugin/README.md

@@ -0,0 +1,300 @@
+# Watchtower client
+
+This is a watchtower client plugin to interact with an [Eye of Satoshi tower](https://github.com/talaia-labs/rust-teos),
+and eventually with any [BOLT13](https://github.com/sr-gi/bolt13/blob/master/13-watchtowers.md) compliant watchtower.
+
+The plugin manages all the client-side logic to send appointment to a number of registered towers every time a new 
+commitment transaction is generated. It also keeps a summary of the messages sent to the towers and their responses.
+
+The plugin has the following methods:
+
+- `registertower <tower_id>`: registers the user id (compressed public key) with a given tower.
+- `gettowerinfo <tower_id>`: gets all the locally stored data about a given tower.
+- `retrytower <tower_id>`: tries to send pending appointment to a (previously) unreachable tower.
+- `abandontower <tower_id>`: deletes all data associated with a given tower.
+- `pingtower <tower_id>`: Polls the tower to check if it is online.
+- `listtowers`: lists all registered towers.
+- `getappointment <tower_id> <locator>`: queries a given tower about an appointment.
+- `getsubscriptioninfo <tower_id>`: gets the subscription information by querying the tower.
+- `getappointmentreceipt <tower_id> <locator>`: pulls a given appointment receipt from the local database.
+- `getregistrationreceipt <tower_id>`: pulls the latest registration receipt from the local database.
+
+The plugin also has an implicit method to send appointments to the registered towers for every new commitment transaction.
+
+# Installing the plugin and linking it to CLN
+
+The first step to add the plugin to CLN is installing it. To do so you need to run (from the `rust-teos` folder):
+
+```
+cargo install --locked --path watchtower-plugin
+```
+
+That will generate a binary called `watchtower-client`. That's the binary we need to link to CLN.
+
+You can link the plugin either via cmd or by placing it in the plugins folder.
+
+### Linking the plugin via cmd
+
+To link the plugin via cmd simply run `lightningd` specifying the plugin to link, that is:
+
+```
+lightningd --plugin=watchtower-client
+```
+
+Notice that you'll need to do this every time you restart your node.
+
+### Linking the plugin via the plugins folder
+
+You can also add a plugin by adding it to the plugins folder so you don't have to link it every single time. In order to do so you need to go to the CLN user directory in your machine (that's usually `~/.lightning`). Once there, you need to create a folder called `plugins` if it does not exist:
+
+```
+cd ~/.lightning
+mkdir plugins && cd plugins
+```
+
+Now you need to place the watchtower-client into this folder. To do so we will create a symbolic link to it. First, check where the binary is placed (this is usually placed in your user's home).
+
+```
+whereis watchtower-client
+> watchtower-client: <your_user_home>/.cargo/bin/watchtower-client
+```
+
+Notice that here `<your_user_home>` will be the path to your user's home directory, for instance `/home/sergi/`. 
+
+Now create a symbolic link to it (make sure to replace the path for your's!):
+
+```
+ln -s <your_user_home>/.cargo/bin/watchtower-client .
+```
+
+If you check the folder you'll see that now there's a link called `watchtower-client`:
+
+```
+ls
+> watchtower-client
+```
+
+You can now turn on your lightning node and the plugin will be automatically linked.
+
+### Check that the client is properly linked
+
+We can check the plugin was properly linked by running:
+
+```
+lightning-cli plugin list
+```
+
+That will return a list of all linked plugins, which should include the `watchtower-client`:
+
+```
+[
+ ...
+  {
+     "name": "~/.lightning/plugins/watchtower-client",
+     "active": true
+  }
+]
+```
+
+# Config file, data folder and first bootstrap
+
+The plugin, by default, creates a data folder under the user's home folder (`~/.watchtower`), where all the plugin's data is stored. The data folder can be modified by setting the ENV variable `TOWERS_DATA_DIR`.
+
+On first bootstrap, the plugin generates a key pair that is used as the user identifier. All requests from the user are signed using the secret key, so the tower can authenticate the user after the registration process (`registertower`).
+
+All the appointments generated by the tower, as well as all the registered towers' data, are stored on a `SQLite3` database under the data dir (that's `~/.watchtower/watchtowers_db.sql3` for the default data dir).
+
+# Core Lightning (CLN) config
+
+Config options can be setup directly in the [CLN config file](https://github.com/ElementsProject/lightning#configuration-file). The currently available options are:
+
+- `watchtower-port`: default tower API port.
+- `watchtower-max-retry-time`: for how long (in seconds) a retry strategy will try to reach a temporary unreachable tower before giving up (default: 1 hour).
+- `watchtower-auto-retry-delay`: how long (in seconds) the client will wait before auto-retrying a failed tower (default: 8 hours).
+- `proxy`: Set a socks v5 proxy IP address and port. Notice this is necessary if you want to connect to a tower through Tor! (default: no proxy).
+- `always-use-proxy`: Use the proxy always (default: false).
+
+Notice `proxy` and `always-use-proxy` are general CLN options that are honored by the plugin, so if set the plugin will use Tor to communicate with the tower.
+
+# Getting started
+
+## Registering with a tower 
+
+Once the plugin is loaded in your node, the first step is to register your node with an active tower. You can do so by running:
+
+```
+lightning-cli registertower tower_id [host, port]
+```
+
+Where `tower_id` represents the target tower public key. As a convenience, `tower_id` may be of the form `tower_id@host` or `id@host:port`. In this case, the host and port parameters must be omitted. Port defaults to `9814` and can be changed in the config file.
+
+### Example
+
+```
+lightning-cli registertower 02bd2b759dd8a4fcef0f7d9692c105da8400d5da7942ee039e869fbfb8738ffde4
+```
+
+If the tower is online, you should get back a response similar to this:
+
+```
+{
+   "user_id": "032fd79e4052531955cf3782b09b495a75919317573ba2fb4dca199652595ced2a",
+   "available_slots": 10000,
+   "subscription_expiry": 4712
+}
+```
+
+Where `available_slots` is the amount of free slots the user has available in the tower, `user_id` is the user's public key and `subscription_expiry` is the block height when the subscription expires. Generally speaking, a slot fits an appointment, so in this example the user can send **10000** appointments in roughly **one month**. 
+
+Notice that, ideally, the client and the tower have to agree on the **subscription details** (`available_slots` and `subscription_expiry`). Currently, those depend only on the tower, since it is offering the service for free. However, in the current state, hitting `registertower` again will add another `10000` slots and reset the time to `current_height + roughtly_one_mont_in_blocks`.
+
+## Sending data to the tower
+Once your node is registered with at least one tower it will start sending appointments to the tower for every commitment transaction update on any of your channels. In the current version of the plugin, everything is sent to every registered tower (**full replication**). There is nothing to be done here, under normal conditions, the plugin takes care of it.
+
+## Checking the state of the towers
+
+To find out more information about registered towers, you can use `list_towers` and `gettowerinfo`:
+
+```
+lightning-cli listtowers
+```
+```
+{
+   "02bd2b759dd8a4fcef0f7d9692c105da8400d5da7942ee039e869fbfb8738ffde4": {
+      "net_addr": "http://localhost:9814",
+      "available_slots": 9996,
+      "subscription_expiry": 4712,
+      "status": "reachable",
+      "pending_appointments": [],
+      "invalid_appointments": []
+   }
+}
+```
+
+The overview contains the `id` and network address of the tower (`netaddr`), as well as the current `status` and two list of appointments: **pending** and **invalid**.
+
+The tower has 5 different states:
+
+- `reachable`: the tower is reachable at the given network address.
+- `temporarily unreachable`: the tower is temporarily unreachable, meaning that one of the last requests sent to it has failed.
+- `unreachable`: the tower has been unreachable for a while.
+- `misbehaving`: the tower has sent us incorrect data.
+- `subscription error`: the subscription with the tower has expired or run out of slots.
+
+The main difference between `temporarily unreachable` and `unreachable` is the amount of time that has passed since we last received a response. If a tower is temporarily unreachable, a backoff strategy is triggered and all the appointments that cannot be delivered are stored under `pending_appointments`. If the tower comes back online within the retry strategy, every pending appointment is sent through and the tower is flagged back as `reachable`. However, if the backoff strategy ends up giving up, the tower is flagged as `unreachable`.
+
+If the client receives data from a tower that is not properly signed, the tower is flagged as `misbehaving` and it is abandoned, meaning that no more appointments are sent to it. This state should never be reached by honest towers.
+
+A `subscription error` means that the subscription needs to be renewed (hit `registertower` again).
+
+Regarding `pending_appointments` and `invalid_appointments` they store the data that is pending to be sent to the tower (for unreachable towers) and the appointments that have been rejected by the tower for being invalid, respectively. The latter should never get populated for honest clients.
+
+`gettowerinfo` provides more detailed information about the tower:
+
+**Usage**
+
+```
+lightning-cli gettowerinfo tower_id
+```
+
+**Call**
+
+```
+lightning-cli gettowerinfo 02bd2b759dd8a4fcef0f7d9692c105da8400d5da7942ee039e869fbfb8738ffde4
+```
+
+**Return**
+
+```
+{
+   "net_addr": "http://localhost:9814",
+   "available_slots": 9996,
+   "subscription_expiry": 4712,
+   "status": "reachable",
+   "appointments": {
+      "b851b8ec05f5809b9a710f7d9d24db6c": "rbxrs8ncqgzyrxkw5h95a64tbeyhmx6wopdtqndktkko3mq8q3tkczjyk19epd713it8warbpnxgk8py6utq87dt16f3qk6ehkjw5c7q",
+      "10c6f7787fc33d6298fa89fc41f6a0eb": "dhrtt91bbswmmu41nu4quszt7bsxzpfyx84ycfc1yjt73rs8eqpqg3fwqq8q9tff8aqorohueo3bcgqrww1ocef38hdfuhna44ikjife",
+      "52dc9bd565bdfe227111927e3964d70b": "d9495n3giiof4rq5aqzh4a6fezftnhofwdi1gb7q5mciyq9besdh4xixczitpgo5dxzdnyzzdy4b9i7hd1zcojdgw833975dn8azfc7x",
+      "e2824d355f711806d38671c19b91110d": "rbxhpeztw74dspxsr3tk7jdekw7cbkt88kfmda4guf5xkmh1tcmeauqf3s15168y8eo438nbpath58qrxsh9usskzmxk8suf1h19meae"
+   },
+   "pending_appointments": {
+      "062dc0f28ce5b31e6902c87ff1de15ee": {
+         "encrypted_blob": "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",
+         "to_self_delay": 42
+      },
+      "ad229060698d4bc2b910a30933b1b50a": {
+         "encrypted_blob": "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",
+         "to_self_delay": 42
+      }
+   },
+   "invalid_appointments": {}
+}
+```
+
+Notice that there are is a new field in this report: `appointments`.
+
+`appointments` contains a collection of `locator:tower_signature` pairs of all the appointments sent and accepted by the tower.
+
+The report may also contain a `misbehaving_proof` field if the tower has misbehaved (this is not the case for this example). The proof would look as follows:
+
+```
+   "misbehaving_proof": {
+      "locator": "3ebd6c5a4d5ec18c815ad9fcda9aac75",
+      "appointment_receipt": {
+         "user_signature": "d7efykp63dy69jrtc3r65pssbdhp4335etq3jap1zqk135qmrtyhr8ghbdhw8y8f7nsjgmm9eoyhsfj6yugzq1bu657frmwwrudr9gpt",
+         "start_block": 391,
+         "signature": "rd41nsmhtjsawhc9pta1p5na7kmsyk48xttjy4bt3tbkbajboyzfq6mpamkjixs1w7qotocwjg3sxnbzg6uduec4cnahhkmctgddjn8w"
+      },
+      "recovered_id": "02bd2b759dd8a4fcef0f7d9692c105da8400d5da7942ee039e869fbfb8738ffde4"
+   }
+```
+
+Finally, notice how `pending_appointments` now contains all the data about the pending appointments (**the full appointment**). The same applies to `invalid_appointments`.
+
+## Manually retrying a tower
+If a tower has been flagged as **unreachable** (after the default backoff has failed) or there has been a **subscription error**, the tower won't be tried again until the user manually requests so. This can be managed with the `retrytower` command:
+
+**Usage**
+
+```
+lightning-cli retrytower tower_id
+```
+**Call**
+
+```
+lightning-cli retrytower 02bd2b759dd8a4fcef0f7d9692c105da8400d5da7942ee039e869fbfb8738ffde4
+```
+**Return**
+
+```
+"Retrying 02bd2b759dd8a4fcef0f7d9692c105da8400d5da7942ee039e869fbfb8738ffde4"
+```
+
+Notice that this only works if the tower is **unreachable**. A tower cannot be retried if it is already being retried (**temporarily unreachable**).
+
+## Query data from a tower
+Data can be queried from a tower to check, for instance, that the tower is keeping it or that it is correct. This can be done using the `getappointment` command:
+
+**Usage**
+
+```
+lightning-cli getappointment tower_id locator
+```
+**Call**
+
+```
+lightning-cli getappointment 02bd2b759dd8a4fcef0f7d9692c105da8400d5da7942ee039e869fbfb8738ffde4 b851b8ec05f5809b9a710f7d9d24db6c
+```
+
+**Return**
+
+```
+{
+   "appointment": {
+      "locator": "b851b8ec05f5809b9a710f7d9d24db6c",
+      "encrypted_blob": "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",
+      "to_self_delay": 42
+   },
+   "status": "being_watched"
+}
+```

watchtower-plugin/src/constants.rs

@@ -0,0 +1,52 @@
+// Collection of ENV variable names and values
+pub const TOWERS_DATA_DIR: &str = "TOWERS_DATA_DIR";
+pub const DEFAULT_TOWERS_DATA_DIR: &str = ".watchtower";
+
+/// Collections of plugin option names, default values and descriptions
+
+pub const WT_PORT: &str = "watchtower-port";
+pub const DEFAULT_WT_PORT: i64 = 9814;
+pub const WT_PORT_DESC: &str = "tower API port";
+pub const WT_MAX_RETRY_TIME: &str = "watchtower-max-retry-time";
+pub const DEFAULT_WT_MAX_RETRY_TIME: i64 = 3600;
+pub const WT_MAX_RETRY_TIME_DESC: &str = "for how long (in seconds) a retry strategy will try to reach a temporary unreachable tower before giving up. Defaults to 1 hour";
+pub const WT_AUTO_RETRY_DELAY: &str = "watchtower-auto-retry-delay";
+pub const DEFAULT_WT_AUTO_RETRY_DELAY: i64 = 28800;
+pub const WT_AUTO_RETRY_DELAY_DESC: &str = "how long (in seconds) a retrier will wait before auto-retrying a failed tower. Defaults to once every 8 hours";
+pub const DEV_WT_MAX_RETRY_INTERVAL: &str = "dev-watchtower-max-retry-interval";
+pub const DEFAULT_DEV_WT_MAX_RETRY_INTERVAL: i64 = 900;
+pub const DEV_WT_MAX_RETRY_INTERVAL_DESC: &str =
+    "maximum length (in seconds) for a retry interval. Defaults to 15 min";
+
+/// Collections of rpc method names and descriptions
+
+pub const RPC_REGISTER_TOWER: &str = "registertower";
+pub const RPC_REGISTER_TOWER_DESC: &str =
+    "Registers the client public key (user id) with the tower";
+pub const RPC_GET_REGISTRATION_RECEIPT: &str = "getregistrationreceipt";
+pub const RPC_GET_REGISTRATION_RECEIPT_DESC: &str =
+    "Gets the latest registration receipt given a tower id";
+pub const RPC_GET_APPOINTMENT: &str = "getappointment";
+pub const RPC_GET_APPOINTMENT_DESC: &str =
+    "Gets appointment data from the tower given a tower id and a locator";
+pub const RPC_GET_APPOINTMENT_RECEIPT: &str = "getappointmentreceipt";
+pub const RPC_GET_APPOINTMENT_RECEIPT_DESC: &str =
+    "Gets a (local) appointment receipt given a tower id and a locator";
+pub const RPC_GET_SUBSCRIPTION_INFO: &str = "getsubscriptioninfo";
+pub const RPC_GET_SUBSCRIPTION_INFO_DESC: &str =
+    "Gets the subscription information directly from the tower";
+pub const RPC_LIST_TOWERS: &str = "listtowers";
+pub const RPC_LIST_TOWERS_DESC: &str = "Lists all registered towers";
+pub const RPC_GET_TOWER_INFO: &str = "gettowerinfo";
+pub const RPC_GET_TOWER_INFO_DESC: &str = "Shows the info about a tower given a tower id";
+pub const RPC_RETRY_TOWER: &str = "retrytower";
+pub const RPC_RETRY_TOWER_DESC: &str =
+    "Retries to send pending appointment to an unreachable tower";
+pub const RPC_ABANDON_TOWER: &str = "abandontower";
+pub const RPC_ABANDON_TOWER_DESC: &str = "Forgets about a tower and wipes all local data";
+pub const RPC_PING: &str = "pingtower";
+pub const RPC_PING_DESC: &str = "Polls the tower to check if it is online";
+
+/// Collections of hook names
+
+pub const HOOK_COMMITMENT_REVOCATION: &str = "commitment_revocation";

watchtower-plugin/src/convert.rs

@@ -0,0 +1,562 @@
+use std::fmt;
+use std::{convert::TryFrom, str::FromStr};
+
+use hex::FromHex;
+use serde::{Deserialize, Serialize};
+use serde_json::json;
+
+use bitcoin::{Transaction, Txid};
+
+use teos_common::appointment::Locator;
+use teos_common::TowerId;
+
+/// Errors related to the `registertower` command.
+#[derive(Debug)]
+pub enum RegisterError {
+    InvalidId(String),
+    InvalidHost(String),
+    InvalidPort(String),
+    InvalidFormat(String),
+}
+
+impl std::fmt::Display for RegisterError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            RegisterError::InvalidId(x) => write!(f, "{x}"),
+            RegisterError::InvalidHost(x) => write!(f, "{x}"),
+            RegisterError::InvalidPort(x) => write!(f, "{x}"),
+            RegisterError::InvalidFormat(x) => write!(f, "{x}"),
+        }
+    }
+}
+
+/// Parameters related to the `registertower` command.
+#[derive(Debug, Serialize)]
+pub struct RegisterParams {
+    pub tower_id: TowerId,
+    pub host: Option<String>,
+    pub port: Option<u16>,
+}
+
+impl RegisterParams {
+    fn new(tower_id: &str, host: Option<&str>, port: Option<u64>) -> Result<Self, RegisterError> {
+        let mut params = RegisterParams::from_id(tower_id)?;
+
+        if host.is_some() {
+            params = params.with_host(host.unwrap())?
+        }
+
+        if port.is_some() {
+            params = params.with_port(port.unwrap())?
+        }
+
+        Ok(params)
+    }
+
+    fn from_id(tower_id: &str) -> Result<Self, RegisterError> {
+        Ok(Self {
+            tower_id: TowerId::from_str(tower_id)
+                .map_err(|_| RegisterError::InvalidId("Invalid tower id".to_owned()))?,
+            host: None,
+            port: None,
+        })
+    }
+
+    fn with_host(self, host: &str) -> Result<Self, RegisterError> {
+        if host.is_empty() {
+            Err(RegisterError::InvalidHost("hostname is empty".to_owned()))
+        } else if host.contains(' ') {
+            Err(RegisterError::InvalidHost(
+                "hostname contains white spaces".to_owned(),
+            ))
+        } else {
+            Ok(Self {
+                host: Some(String::from(host)),
+                ..self
+            })
+        }
+    }
+
+    fn with_port(self, port: u64) -> Result<Self, RegisterError> {
+        if port > u16::MAX as u64 {
+            Err(RegisterError::InvalidPort(format!(
+                "port must be a 16-byte integer. Received: {port}"
+            )))
+        } else {
+            Ok(Self {
+                port: Some(port as u16),
+                ..self
+            })
+        }
+    }
+}
+
+impl TryFrom<serde_json::Value> for RegisterParams {
+    type Error = RegisterError;
+
+    // clippy-fix: We are getting more than just the first item, so this clippy check does not make sense here
+    #[allow(clippy::get_first)]
+    fn try_from(value: serde_json::Value) -> Result<Self, Self::Error> {
+        match value {
+            serde_json::Value::String(s) => {
+                let s = s.trim();
+                let mut v = s.split('@');
+                let tower_id = v.next().unwrap();
+
+                match v.next() {
+                    Some(x) => {
+                        let mut v = x.split(':');
+                        let host = v.next();
+                        let port = if let Some(p) = v.next() {
+                            p.parse()
+                                .map(Some)
+                                .map_err(|_| RegisterError::InvalidPort(format!("Port is not a number: {p}")))?
+                        } else {
+                            None
+                        };
+
+                        RegisterParams::new(tower_id, host, port)
+                    }
+                    None => RegisterParams::from_id(tower_id),
+                }
+            },
+            serde_json::Value::Array(mut a) => {
+                let param_count = a.len();
+
+                match param_count {
+                    1 => RegisterParams::try_from(a.pop().unwrap()),
+                    2 | 3 => {
+                        let tower_id = a.get(0).unwrap().as_str().ok_or_else(|| RegisterError::InvalidId("tower_id must be a string".to_string()))?;
+                        let host = Some(a.get(1).unwrap().as_str().ok_or_else(|| RegisterError::InvalidHost("host must be a string".to_string()))?);
+                        let port = if let Some(p) = a.get(2) {
+                            Some(p.as_u64().ok_or_else(|| RegisterError::InvalidPort(format!("port must be a number. Received: {p}")))?)
+                        } else {
+                            None
+                        };
+
+                        RegisterParams::new(tower_id, host, port)
+                    }
+                    _ => Err(RegisterError::InvalidFormat(format!("Unexpected request format. The request needs 1-3 parameters. Received: {param_count}"))),
+                }
+            },
+            serde_json::Value::Object(mut m) => {
+                let allowed_keys = ["tower_id", "host", "port"];
+                let param_count = m.len();
+
+                 if m.is_empty() || param_count > allowed_keys.len() {
+                    Err(RegisterError::InvalidFormat(format!("Unexpected request format. The request needs 1-3 parameters. Received: {param_count}")))
+                 } else if !m.contains_key(allowed_keys[0]){
+                    Err(RegisterError::InvalidId(format!("{} is mandatory", allowed_keys[0])))
+                 } else if !m.iter().all(|(k, _)| allowed_keys.contains(&k.as_str())) {
+                    Err(RegisterError::InvalidFormat("Invalid named parameter found in request".to_owned()))
+                 } else {
+                    let mut params = Vec::with_capacity(allowed_keys.len());
+                    for k in allowed_keys {
+                        if let Some(v) = m.remove(k) {
+                            params.push(v);
+                        }
+                    }
+
+                    RegisterParams::try_from(json!(params))
+                }
+            },
+            _ => Err(RegisterError::InvalidFormat(
+                format!("Unexpected request format. Expected: 'tower_id[@host][:port]' or 'tower_id [host] [port]'. Received: '{value}'"),
+            )),
+        }
+    }
+}
+
+/// Errors related to the `getappointment` command.
+#[derive(Debug)]
+pub enum GetAppointmentError {
+    InvalidId(String),
+    InvalidLocator(String),
+    InvalidFormat(String),
+}
+
+impl std::fmt::Display for GetAppointmentError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            GetAppointmentError::InvalidId(x) => write!(f, "{x}"),
+            GetAppointmentError::InvalidLocator(x) => write!(f, "{x}"),
+            GetAppointmentError::InvalidFormat(x) => write!(f, "{x}"),
+        }
+    }
+}
+
+/// Parameters related to the `getappointment` command.
+#[derive(Debug)]
+pub struct GetAppointmentParams {
+    pub tower_id: TowerId,
+    pub locator: Locator,
+}
+
+impl TryFrom<serde_json::Value> for GetAppointmentParams {
+    type Error = GetAppointmentError;
+
+    // clippy-fix: We are getting more than just the first item, so this clippy check does not make sense here
+    #[allow(clippy::get_first)]
+    fn try_from(value: serde_json::Value) -> Result<Self, Self::Error> {
+        match value {
+            serde_json::Value::Array(a) => {
+                let param_count = a.len();
+                if param_count != 2 {
+                    Err(GetAppointmentError::InvalidFormat(format!(
+                        "Unexpected request format. The request needs 2 parameter. Received: {param_count}"
+                    )))
+                } else {
+                    let tower_id = if let Some(s) = a.get(0).unwrap().as_str() {
+                        TowerId::from_str(s).map_err(|_| {
+                            GetAppointmentError::InvalidId("Invalid tower id".to_owned())
+                        })
+                    } else {
+                        Err(GetAppointmentError::InvalidId(
+                            "tower_id must be a hex encoded string".to_owned(),
+                        ))
+                    }?;
+
+                    let locator = if let Some(s) = a.get(1).unwrap().as_str() {
+                        Locator::from_hex(s).map_err(|_| {
+                            GetAppointmentError::InvalidLocator("Invalid locator".to_owned())
+                        })
+                    } else {
+                        Err(GetAppointmentError::InvalidLocator(
+                            "locator must be a hex encoded string".to_owned(),
+                        ))
+                    }?;
+
+                    Ok(Self { tower_id, locator })
+                }
+            }
+            serde_json::Value::Object(mut m) => {
+                let allowed_keys = ["tower_id", "locator"];
+
+                if m.len() > allowed_keys.len() {
+                    return Err(GetAppointmentError::InvalidFormat(
+                        "Invalid named argument found in request".to_owned(),
+                    ));
+                }
+
+                // DISCUSS: There may be a more idiomatic way of doing this
+                for k in allowed_keys.iter() {
+                    if !m.contains_key(*k) {
+                        return Err(GetAppointmentError::InvalidFormat(format!(
+                            "{k} is mandatory"
+                        )));
+                    }
+                }
+
+                let mut params = Vec::with_capacity(allowed_keys.len());
+                for k in allowed_keys {
+                    if let Some(v) = m.remove(k) {
+                        params.push(v);
+                    }
+                }
+                GetAppointmentParams::try_from(json!(params))
+            }
+            _ => Err(GetAppointmentError::InvalidFormat(format!(
+                "Unexpected request format. Expected: tower_id locator. Received: '{value}'"
+            ))),
+        }
+    }
+}
+
+/// Data associated with a commitment revocation. Represents the data sent by CoreLN through the `commitment_revocation` hook.
+#[derive(Debug, Serialize, Deserialize)]
+pub struct CommitmentRevocation {
+    pub channel_id: String,
+    #[serde(rename(deserialize = "commitnum"))]
+    pub commit_num: u32,
+    pub commitment_txid: Txid,
+    #[serde(deserialize_with = "crate::ser::deserialize_tx")]
+    pub penalty_tx: Transaction,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+    use std::collections::HashMap;
+
+    const VALID_ID: &str = "020dea894c967319407265764aba31bdef75d463f96800f34dd6df61380d82dfc0";
+
+    mod register_command {
+        use super::*;
+
+        #[test]
+        fn test_from_id() {
+            // The tower id should be a valid id, otherwise the params construction will fail
+            let params = RegisterParams::from_id(VALID_ID).unwrap();
+            assert!(params.host.is_none());
+            assert!(params.port.is_none());
+
+            // Any incorrectly formatted id will make it fail
+            assert!(matches!(
+                RegisterParams::from_id(""),
+                Err(RegisterError::InvalidId(..))
+            ));
+        }
+
+        #[test]
+        fn test_with_host() {
+            // Any properly formatted host should work
+            let params = RegisterParams::from_id(VALID_ID).unwrap();
+            let host = "myhost";
+            assert_eq!(params.with_host(host).unwrap().host, Some(host.to_owned()));
+
+            // Host must not be empty not have spaces
+            assert!(matches!(
+                RegisterParams::from_id(VALID_ID).unwrap().with_host(""),
+                Err(RegisterError::InvalidHost(..))
+            ));
+            assert!(matches!(
+                RegisterParams::from_id(VALID_ID)
+                    .unwrap()
+                    .with_host("myhost "),
+                Err(RegisterError::InvalidHost(..))
+            ));
+        }
+
+        #[test]
+        fn test_with_port() {
+            let mut params = RegisterParams::from_id(VALID_ID).unwrap();
+
+            // Any 16-bytes value will do for the port
+            let port = 6677;
+            params = params.with_port(port).unwrap();
+            assert_eq!(params.port, Some(port as u16));
+
+            // Going over u16::MAX will make this fail
+            let port = u16::MAX as u64 + 1;
+            assert!(matches!(
+                params.with_port(port),
+                Err(RegisterError::InvalidPort(..))
+            ));
+        }
+
+        #[test]
+        fn test_try_from_json_string() {
+            let ok = [
+                format!("{VALID_ID}@host:80"),
+                format!("{VALID_ID}@host"),
+                VALID_ID.to_string(),
+            ];
+            let wrong_id = ["", "id@host:80", "@host:80", "@:80"];
+            let wrong_host = [
+                format!("{VALID_ID}@"),
+                format!("{VALID_ID}@ "),
+                format!("{VALID_ID}@ host"),
+                format!("{VALID_ID}@:80"),
+            ];
+            let wrong_port = [format!("{VALID_ID}@host:"), format!("{VALID_ID}@host:port")];
+
+            for s in ok {
+                let v = serde_json::Value::Array(vec![serde_json::Value::String(s.to_string())]);
+                let p = RegisterParams::try_from(v);
+                assert!(matches!(p, Ok(..)));
+            }
+
+            for s in wrong_id {
+                let v = serde_json::Value::Array(vec![serde_json::Value::String(s.to_string())]);
+                let p = RegisterParams::try_from(v);
+                assert!(matches!(p, Err(RegisterError::InvalidId(..))));
+            }
+
+            for s in wrong_host {
+                let v = serde_json::Value::Array(vec![serde_json::Value::String(s.to_string())]);
+                let p = RegisterParams::try_from(v);
+                assert!(matches!(p, Err(RegisterError::InvalidHost(..))));
+            }
+
+            for s in wrong_port {
+                let v = serde_json::Value::Array(vec![serde_json::Value::String(s.to_string())]);
+                let p = RegisterParams::try_from(v);
+                assert!(matches!(p, Err(RegisterError::InvalidPort(..))));
+            }
+        }
+
+        #[test]
+        fn test_try_from_json_array() {
+            let id = json!(VALID_ID);
+            let number_id = json!(0);
+
+            let host = json!("host");
+            let number_host = json!(1);
+
+            let port = json!(80);
+            let string_port = json!("80");
+
+            for v in [vec![&id, &host, &port], vec![&id, &host], vec![&id]] {
+                let p = RegisterParams::try_from(json!(v));
+                assert!(matches!(p, Ok(..)));
+            }
+
+            // Wrong id
+            let p = RegisterParams::try_from(json!(vec![&number_id, &host, &port]));
+            assert!(matches!(p, Err(RegisterError::InvalidId(..))));
+
+            // Wrong host
+            let p = RegisterParams::try_from(json!(vec![&id, &number_host, &port]));
+            assert!(matches!(p, Err(RegisterError::InvalidHost(..))));
+
+            // Wrong port
+            let p = RegisterParams::try_from(json!(vec![&id, &host, &string_port]));
+            assert!(matches!(p, Err(RegisterError::InvalidPort(..))));
+
+            // Wrong param count (params should be 1-3)
+            let p = RegisterParams::try_from(json!(vec![&id, &host, &port, &id]));
+            assert!(matches!(p, Err(RegisterError::InvalidFormat(..))));
+        }
+
+        #[test]
+        fn test_try_from_json_dict() {
+            let id = json!(VALID_ID);
+            let host = json!("host");
+            let port = json!(80);
+
+            for v in [
+                HashMap::from([("tower_id", &id), ("host", &host), ("port", &port)]),
+                HashMap::from([("tower_id", &id), ("host", &host)]),
+                HashMap::from([("tower_id", &id)]),
+            ] {
+                let p = RegisterParams::try_from(json!(v));
+                assert!(matches!(p, Ok(..)));
+            }
+
+            // Id key missing
+            let p =
+                RegisterParams::try_from(json!(HashMap::from([("host", &host), ("port", &port)])));
+            assert!(matches!(p, Err(RegisterError::InvalidId(..))));
+
+            // Wrong id key
+            let p = RegisterParams::try_from(json!(HashMap::from([
+                ("wrong_tower_id", &id),
+                ("tower_id", &id),
+                ("host", &host),
+                ("port", &port)
+            ])));
+            assert!(matches!(p, Err(RegisterError::InvalidFormat(..))));
+
+            // Wrong host key
+            let p = RegisterParams::try_from(json!(HashMap::from([
+                ("tower_id", &id),
+                ("wrong_host", &host),
+                ("port", &port)
+            ])));
+            assert!(matches!(p, Err(RegisterError::InvalidFormat(..))));
+
+            // Wrong port key
+            let p = RegisterParams::try_from(json!(HashMap::from([
+                ("tower_id", &id),
+                ("host", &host),
+                ("wrong_port", &port)
+            ])));
+            assert!(matches!(p, Err(RegisterError::InvalidFormat(..))));
+
+            // Wrong param count (params should be 1-3)
+            let p = RegisterParams::try_from(json!(HashMap::from([
+                ("tower_id", &id),
+                ("host", &host),
+                ("port", &port),
+                ("another_param", &json!(0))
+            ])));
+            assert!(matches!(p, Err(RegisterError::InvalidFormat(..))));
+        }
+
+        #[test]
+        fn test_try_from_other_json() {
+            // Unexpected json object (it must be either String or Array)
+            let p = RegisterParams::try_from(json!(true));
+            assert!(matches!(p, Err(RegisterError::InvalidFormat(..))));
+        }
+    }
+
+    mod get_appointment_command {
+        use super::*;
+
+        #[test]
+        fn test_try_from_array() {
+            let id = json!(VALID_ID);
+            let wrong_id =
+                json!("050dea894c967319407265764aba31bdef75d463f96800f34dd6df61380d82dfc0");
+            let number_id = json!(0);
+
+            let locator = json!("c69517f00d9482e6b1c41639f9bdfd5c");
+            let wrong_locator =
+                json!("c69517f00d9482e6b1c41639f9bdfd5cc69517f00d9482e6b1c41639f9bdfd5c");
+            let number_locator = json!(1);
+
+            // Valid params
+            let p = GetAppointmentParams::try_from(json!(vec![&id, &locator]));
+            assert!(matches!(p, Ok(..)));
+
+            // Wrong params
+            // Id is a hex string but the format is wrong (wrong prefix)
+            let p = GetAppointmentParams::try_from(json!(vec![&wrong_id, &locator]));
+            assert!(matches!(p, Err(GetAppointmentError::InvalidId(..))));
+            // Ud is not a hex string
+            let p = GetAppointmentParams::try_from(json!(vec![&number_id, &wrong_locator]));
+            assert!(matches!(p, Err(GetAppointmentError::InvalidId(..))));
+
+            // Locator is a hex string but not properly formatted (wrong length)
+            let p = GetAppointmentParams::try_from(json!(vec![&id, &wrong_locator]));
+            assert!(matches!(p, Err(GetAppointmentError::InvalidLocator(..))));
+            // Locator is not a hex string
+            let p = GetAppointmentParams::try_from(json!(vec![&id, &number_locator]));
+            assert!(matches!(p, Err(GetAppointmentError::InvalidLocator(..))));
+        }
+
+        #[test]
+        fn test_try_from_dict() {
+            let id = json!(VALID_ID);
+            let locator = json!("c69517f00d9482e6b1c41639f9bdfd5c");
+
+            // Valid params
+            let p = GetAppointmentParams::try_from(json!(HashMap::from([
+                ("tower_id", &id),
+                ("locator", &locator)
+            ])));
+            assert!(matches!(p, Ok(..)));
+
+            // Wrong keys
+            let p = GetAppointmentParams::try_from(json!(HashMap::from([
+                ("wrong_tower_id", &id),
+                ("locator", &locator)
+            ])));
+            assert!(matches!(p, Err(GetAppointmentError::InvalidFormat(..))));
+
+            let p = GetAppointmentParams::try_from(json!(HashMap::from([
+                ("tower_id", &id),
+                ("wrong_locator", &locator)
+            ])));
+            assert!(matches!(p, Err(GetAppointmentError::InvalidFormat(..))));
+
+            // Too many parameters
+            let p = GetAppointmentParams::try_from(json!(HashMap::from([
+                ("tower_id", &id),
+                ("locator", &locator),
+                ("another_param", &json!(0))
+            ])));
+            assert!(matches!(p, Err(GetAppointmentError::InvalidFormat(..))));
+        }
+
+        #[test]
+        fn test_try_from_other_json() {
+            // Unexpected json object (it must be either String or Array)
+            let p = RegisterParams::try_from(json!(true));
+            assert!(matches!(p, Err(RegisterError::InvalidFormat(..))));
+        }
+
+        #[test]
+        fn test_wrong_param_count() {
+            // The param count for get_appointment must be 2.
+            let params_vec = [vec![], vec![1], vec![1, 2, 3]];
+
+            for params in params_vec {
+                let p = GetAppointmentParams::try_from(json!(params));
+                assert!(matches!(p, Err(..)));
+            }
+        }
+    }
+}

watchtower-plugin/src/lib.rs

@@ -0,0 +1,524 @@
+use std::collections::{HashMap, HashSet};
+use std::fmt;
+
+use serde::Serialize;
+
+use teos_common::appointment::{Appointment, Locator};
+use teos_common::net::NetAddr;
+use teos_common::receipts::AppointmentReceipt;
+use teos_common::TowerId;
+
+pub mod constants;
+pub mod convert;
+pub mod dbm;
+pub mod net;
+pub mod retrier;
+mod ser;
+pub mod wt_client;
+
+#[cfg(test)]
+mod test_utils;
+
+/// The status the tower can be found at.
+#[derive(Clone, Serialize, PartialEq, Eq, Copy, Debug)]
+#[serde(rename_all = "snake_case")]
+pub enum TowerStatus {
+    Reachable,
+    TemporaryUnreachable,
+    Unreachable,
+    SubscriptionError,
+    Misbehaving,
+}
+
+/// The status an appointment can be at.
+pub enum AppointmentStatus {
+    Accepted,
+    Pending,
+    Invalid,
+}
+
+/// Errors related to updating a subscription
+#[derive(Debug, PartialEq, Eq)]
+pub enum SubscriptionError {
+    Expiry,
+    Slots,
+}
+
+impl SubscriptionError {
+    /// Whether the error is related to the expiry time or not.
+    pub fn is_expiry(&self) -> bool {
+        *self == SubscriptionError::Expiry
+    }
+}
+
+impl fmt::Display for TowerStatus {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "{}",
+            match self {
+                TowerStatus::Reachable => "reachable",
+                TowerStatus::TemporaryUnreachable => "temporary unreachable",
+                TowerStatus::Unreachable => "unreachable",
+                TowerStatus::SubscriptionError => "subscription error",
+                TowerStatus::Misbehaving => "misbehaving",
+            }
+        )
+    }
+}
+
+impl TowerStatus {
+    /// Whether the tower is reachable or not.
+    pub fn is_reachable(&self) -> bool {
+        *self == TowerStatus::Reachable
+    }
+
+    /// Whether the tower is unreachable or not.
+    pub fn is_temporary_unreachable(&self) -> bool {
+        *self == TowerStatus::TemporaryUnreachable
+    }
+
+    /// Whether the tower is unreachable or not.
+    pub fn is_unreachable(&self) -> bool {
+        *self == TowerStatus::Unreachable
+    }
+
+    /// Whether the tower is misbehaving or not.
+    pub fn is_misbehaving(&self) -> bool {
+        *self == TowerStatus::Misbehaving
+    }
+
+    /// Whether there is a subscription issue with the tower.
+    pub fn is_subscription_error(&self) -> bool {
+        *self == TowerStatus::SubscriptionError
+    }
+
+    /// Whether the tower can be manually retried
+    pub fn is_retryable(&self) -> bool {
+        self.is_unreachable() || self.is_subscription_error()
+    }
+}
+
+/// Summarized data associated with a given tower.
+#[derive(Clone, Serialize, Debug, PartialEq, Eq)]
+pub struct TowerSummary {
+    #[serde(flatten)]
+    pub net_addr: NetAddr,
+    pub available_slots: u32,
+    subscription_start: u32,
+    pub subscription_expiry: u32,
+    pub status: TowerStatus,
+    #[serde(serialize_with = "teos_common::ser::serialize_locators")]
+    pub pending_appointments: HashSet<Locator>,
+    #[serde(serialize_with = "teos_common::ser::serialize_locators")]
+    pub invalid_appointments: HashSet<Locator>,
+}
+
+impl TowerSummary {
+    /// Creates a new [TowerSummary] instance.
+    pub fn new(
+        net_addr: String,
+        available_slots: u32,
+        subscription_start: u32,
+        subscription_expiry: u32,
+    ) -> Self {
+        Self {
+            net_addr: NetAddr::new(net_addr),
+            available_slots,
+            subscription_start,
+            subscription_expiry,
+            status: TowerStatus::Reachable,
+            pending_appointments: HashSet::new(),
+            invalid_appointments: HashSet::new(),
+        }
+    }
+
+    /// Creates a new instance with some associated appointment data.
+    pub fn with_appointments(
+        net_addr: String,
+        available_slots: u32,
+        subscription_start: u32,
+        subscription_expiry: u32,
+        pending_appointments: HashSet<Locator>,
+        invalid_appointments: HashSet<Locator>,
+    ) -> Self {
+        Self {
+            net_addr: NetAddr::new(net_addr),
+            available_slots,
+            subscription_start,
+            subscription_expiry,
+            status: TowerStatus::Reachable,
+            pending_appointments,
+            invalid_appointments,
+        }
+    }
+
+    /// Creates a new instance using the existing info but updating the status.
+    pub fn with_status(mut self, status: TowerStatus) -> Self {
+        self.status = status;
+        self
+    }
+
+    /// Updates the main information about the summary while preserving the appointment maps.
+    pub fn udpate(
+        &mut self,
+        net_addr: String,
+        available_slots: u32,
+        subscription_start: u32,
+        subscription_expiry: u32,
+    ) {
+        self.net_addr = NetAddr::new(net_addr);
+        self.available_slots = available_slots;
+        self.subscription_start = subscription_start;
+        self.subscription_expiry = subscription_expiry;
+    }
+}
+
+impl From<TowerInfo> for TowerSummary {
+    fn from(info: TowerInfo) -> Self {
+        TowerSummary::with_appointments(
+            info.net_addr,
+            info.available_slots,
+            info.subscription_start,
+            info.subscription_expiry,
+            info.pending_appointments
+                .iter()
+                .map(|a| a.locator)
+                .collect(),
+            info.invalid_appointments
+                .iter()
+                .map(|a| a.locator)
+                .collect(),
+        )
+        .with_status(info.status)
+    }
+}
+
+/// Summarized data associated with a given tower.
+#[derive(Clone, Serialize, Debug, PartialEq, Eq)]
+pub struct TowerInfo {
+    pub net_addr: String,
+    pub available_slots: u32,
+    pub subscription_start: u32,
+    pub subscription_expiry: u32,
+    pub status: TowerStatus,
+    #[serde(serialize_with = "crate::ser::serialize_receipts")]
+    pub appointments: HashMap<Locator, String>,
+    #[serde(serialize_with = "crate::ser::serialize_appointments")]
+    pub pending_appointments: Vec<Appointment>,
+    #[serde(serialize_with = "crate::ser::serialize_appointments")]
+    pub invalid_appointments: Vec<Appointment>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub misbehaving_proof: Option<MisbehaviorProof>,
+}
+
+impl TowerInfo {
+    /// Creates a new [TowerInfo] instance.
+    pub fn new(
+        net_addr: String,
+        available_slots: u32,
+        subscription_start: u32,
+        subscription_expiry: u32,
+        appointments: HashMap<Locator, String>,
+        pending_appointments: Vec<Appointment>,
+        invalid_appointments: Vec<Appointment>,
+    ) -> Self {
+        Self {
+            net_addr,
+            available_slots,
+            subscription_start,
+            subscription_expiry,
+            status: TowerStatus::Reachable,
+            appointments,
+            pending_appointments,
+            invalid_appointments,
+            misbehaving_proof: None,
+        }
+    }
+
+    /// Creates a new instance using the existing info but updating the status.
+    pub fn with_status(mut self, status: TowerStatus) -> Self {
+        self.status = status;
+        self
+    }
+
+    /// Sets the misbehaving proof of a tower.
+    pub fn set_misbehaving_proof(&mut self, proof: MisbehaviorProof) {
+        self.misbehaving_proof = Some(proof);
+    }
+}
+
+/// A misbehaving proof. Contains proof of a tower replying with a public key different from the advertised one.
+#[derive(Clone, Serialize, Debug, PartialEq, Eq)]
+pub struct MisbehaviorProof {
+    #[serde(with = "hex::serde")]
+    pub locator: Locator,
+    pub appointment_receipt: AppointmentReceipt,
+    pub recovered_id: TowerId,
+}
+
+impl MisbehaviorProof {
+    /// Creates a new [MisbehavingProof] instance.
+    pub fn new(
+        locator: Locator,
+        appointment_receipt: AppointmentReceipt,
+        recovered_id: TowerId,
+    ) -> Self {
+        Self {
+            locator,
+            appointment_receipt,
+            recovered_id,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const STATUSES: [TowerStatus; 5] = [
+        TowerStatus::Reachable,
+        TowerStatus::TemporaryUnreachable,
+        TowerStatus::Unreachable,
+        TowerStatus::SubscriptionError,
+        TowerStatus::Misbehaving,
+    ];
+
+    const AVAILABLE_SLOTS: u32 = 21;
+    const SUBSCRIPTION_START: u32 = 100;
+    const SUBSCRIPTION_EXPIRY: u32 = SUBSCRIPTION_START + 42;
+
+    mod tower_status {
+        use super::*;
+        use TowerStatus::*;
+
+        #[test]
+        fn test_is_reachable() {
+            for status in STATUSES {
+                if status == Reachable {
+                    assert!(status.is_reachable())
+                } else {
+                    assert!(!status.is_reachable());
+                }
+            }
+        }
+
+        #[test]
+        fn test_is_temporary_reachable() {
+            for status in STATUSES {
+                if status == TemporaryUnreachable {
+                    assert!(status.is_temporary_unreachable())
+                } else {
+                    assert!(!status.is_temporary_unreachable());
+                }
+            }
+        }
+
+        #[test]
+        fn test_is_unreachable() {
+            for status in STATUSES {
+                if status == Unreachable {
+                    assert!(status.is_unreachable())
+                } else {
+                    assert!(!status.is_unreachable());
+                }
+            }
+        }
+
+        #[test]
+        fn test_is_misbehaving() {
+            for status in STATUSES {
+                if status == Misbehaving {
+                    assert!(status.is_misbehaving())
+                } else {
+                    assert!(!status.is_misbehaving());
+                }
+            }
+        }
+
+        #[test]
+        fn test_is_subscription_error() {
+            for status in STATUSES {
+                if status == SubscriptionError {
+                    assert!(status.is_subscription_error())
+                } else {
+                    assert!(!status.is_subscription_error());
+                }
+            }
+        }
+
+        #[test]
+        fn test_is_retryable() {
+            for status in STATUSES {
+                if status == Unreachable || status == SubscriptionError {
+                    assert!(status.is_retryable())
+                } else {
+                    assert!(!status.is_retryable());
+                }
+            }
+        }
+    }
+
+    mod tower_summary {
+        use super::*;
+
+        use std::iter::FromIterator;
+
+        use teos_common::test_utils::generate_random_appointment;
+
+        impl TowerSummary {
+            pub fn set_net_addr(&mut self, net_addr: String) {
+                self.net_addr = NetAddr::new(net_addr);
+            }
+        }
+
+        #[test]
+        fn test_new() {
+            let net_addr: String = "addr".to_owned();
+
+            let tower_summary = TowerSummary::new(
+                net_addr.clone(),
+                AVAILABLE_SLOTS,
+                SUBSCRIPTION_START,
+                SUBSCRIPTION_EXPIRY,
+            );
+            assert_eq!(
+                tower_summary,
+                TowerSummary {
+                    net_addr: NetAddr::new(net_addr),
+                    available_slots: AVAILABLE_SLOTS,
+                    subscription_start: SUBSCRIPTION_START,
+                    subscription_expiry: SUBSCRIPTION_EXPIRY,
+                    status: TowerStatus::Reachable,
+                    pending_appointments: HashSet::new(),
+                    invalid_appointments: HashSet::new(),
+                },
+            );
+        }
+
+        #[test]
+        fn test_with_appointments() {
+            let net_addr: String = "addr".to_owned();
+
+            let pending_appointments =
+                HashSet::from_iter([generate_random_appointment(None).locator]);
+            let invalid_appointments =
+                HashSet::from_iter([generate_random_appointment(None).locator]);
+
+            let tower_summary = TowerSummary::with_appointments(
+                net_addr.clone(),
+                AVAILABLE_SLOTS,
+                SUBSCRIPTION_START,
+                SUBSCRIPTION_EXPIRY,
+                pending_appointments.clone(),
+                invalid_appointments.clone(),
+            );
+            assert_eq!(
+                tower_summary,
+                TowerSummary {
+                    net_addr: NetAddr::new(net_addr),
+                    available_slots: AVAILABLE_SLOTS,
+                    subscription_start: SUBSCRIPTION_START,
+                    subscription_expiry: SUBSCRIPTION_EXPIRY,
+                    status: TowerStatus::Reachable,
+                    pending_appointments,
+                    invalid_appointments,
+                },
+            );
+        }
+
+        #[test]
+        fn test_with_status() {
+            let mut tower_summary = TowerSummary::new(
+                "addr".to_owned(),
+                AVAILABLE_SLOTS,
+                SUBSCRIPTION_START,
+                SUBSCRIPTION_EXPIRY,
+            );
+
+            let unreachable_tower = tower_summary.clone().with_status(TowerStatus::Unreachable);
+            tower_summary.status = TowerStatus::Unreachable;
+            assert_eq!(unreachable_tower, tower_summary);
+        }
+    }
+
+    mod tower_info {
+        use super::*;
+
+        use teos_common::test_utils::{generate_random_appointment, get_random_user_id};
+
+        impl TowerInfo {
+            pub fn empty(
+                net_addr: String,
+                available_slots: u32,
+                subscription_start: u32,
+                subscription_expiry: u32,
+            ) -> Self {
+                TowerInfo::new(
+                    net_addr,
+                    available_slots,
+                    subscription_start,
+                    subscription_expiry,
+                    HashMap::new(),
+                    Vec::new(),
+                    Vec::new(),
+                )
+            }
+        }
+
+        #[test]
+        fn test_new() {
+            let tower_info = TowerInfo::new(
+                "addr".to_owned(),
+                AVAILABLE_SLOTS,
+                SUBSCRIPTION_START,
+                SUBSCRIPTION_EXPIRY,
+                HashMap::new(),
+                Vec::new(),
+                Vec::new(),
+            );
+
+            assert!(tower_info.status.is_reachable());
+            assert!(tower_info.misbehaving_proof.is_none());
+        }
+
+        #[test]
+        fn test_with_status() {
+            let mut tower_info = TowerInfo::empty(
+                "addr".to_owned(),
+                AVAILABLE_SLOTS,
+                SUBSCRIPTION_START,
+                SUBSCRIPTION_EXPIRY,
+            );
+
+            let unreachable_tower = tower_info.clone().with_status(TowerStatus::Unreachable);
+            tower_info.status = TowerStatus::Unreachable;
+            assert_eq!(unreachable_tower, tower_info);
+        }
+
+        #[test]
+        fn test_set_misbehaving_proof() {
+            let mut tower_info = TowerInfo::empty(
+                "addr".to_owned(),
+                AVAILABLE_SLOTS,
+                SUBSCRIPTION_START,
+                SUBSCRIPTION_EXPIRY,
+            );
+            assert_eq!(tower_info.misbehaving_proof, None);
+
+            let appointment_receipt = AppointmentReceipt::with_signature(
+                "user_signature".to_owned(),
+                SUBSCRIPTION_START + 1,
+                "tower_signature".to_owned(),
+            );
+            let proof = MisbehaviorProof::new(
+                generate_random_appointment(None).locator,
+                appointment_receipt,
+                get_random_user_id(),
+            );
+
+            tower_info.set_misbehaving_proof(proof.clone());
+            assert_eq!(tower_info.misbehaving_proof, Some(proof));
+        }
+    }
+}

watchtower-plugin/src/main.rs

@@ -0,0 +1,670 @@
+use std::convert::TryFrom;
+use std::env;
+use std::path::PathBuf;
+use std::sync::{Arc, Mutex, MutexGuard};
+
+use home::home_dir;
+use serde_json::json;
+use tokio::io::{stdin, stdout};
+use tokio::sync::mpsc::unbounded_channel;
+
+use cln_plugin::options::config_type::DefaultInteger;
+use cln_plugin::options::ConfigOption;
+use cln_plugin::{anyhow, Builder, Error, Plugin};
+
+use teos_common::appointment::{Appointment, Locator};
+use teos_common::net::http::Endpoint;
+use teos_common::net::NetAddr;
+use teos_common::protos as common_msgs;
+use teos_common::TowerId;
+use teos_common::{cryptography, errors};
+
+use watchtower_plugin::convert::{CommitmentRevocation, GetAppointmentParams, RegisterParams};
+use watchtower_plugin::net::http::{
+    self, get_request, post_request, process_post_response, AddAppointmentError, ApiResponse,
+    RequestError,
+};
+use watchtower_plugin::net::ProxyInfo;
+use watchtower_plugin::retrier::RetryManager;
+use watchtower_plugin::wt_client::{RevocationData, WTClient};
+use watchtower_plugin::{constants, TowerStatus};
+
+const DEV_WT_MAX_RETRY_INTERVAL_CONFIG: ConfigOption<DefaultInteger> =
+    ConfigOption::new_i64_with_default(
+        constants::DEV_WT_MAX_RETRY_INTERVAL,
+        constants::DEFAULT_DEV_WT_MAX_RETRY_INTERVAL,
+        constants::DEV_WT_MAX_RETRY_INTERVAL_DESC,
+    );
+
+const WT_AUTO_RETRY_DELAY_CONFIG: ConfigOption<DefaultInteger> = ConfigOption::new_i64_with_default(
+    constants::WT_AUTO_RETRY_DELAY,
+    constants::DEFAULT_WT_AUTO_RETRY_DELAY,
+    constants::WT_AUTO_RETRY_DELAY_DESC,
+);
+
+const WT_MAX_RETRY_TIME_CONFIG: ConfigOption<DefaultInteger> = ConfigOption::new_i64_with_default(
+    constants::WT_MAX_RETRY_TIME,
+    constants::DEFAULT_WT_MAX_RETRY_TIME,
+    constants::WT_MAX_RETRY_TIME_DESC,
+);
+
+const WT_PORT_CONFG: ConfigOption<DefaultInteger> = ConfigOption::new_i64_with_default(
+    constants::WT_PORT,
+    constants::DEFAULT_WT_PORT,
+    constants::WT_PORT_DESC,
+);
+
+fn to_cln_error(e: RequestError) -> Error {
+    let e = match e {
+        RequestError::ConnectionError(e) => anyhow!(e),
+        RequestError::DeserializeError(e) => anyhow!(e),
+        RequestError::Unexpected(e) => anyhow!(e),
+    };
+    log::info!("{e}");
+    e
+}
+
+/// Sends fresh data to a retrier as long as is does not exist, or it does and its running.
+fn send_to_retrier(state: &MutexGuard<WTClient>, tower_id: TowerId, locator: Locator) {
+    if if let Some(status) = state.get_retrier_status(&tower_id) {
+        // A retrier in the retriers map can only be running or idle
+        status.is_running()
+    } else {
+        true
+    } {
+        state
+            .unreachable_towers
+            .send((tower_id, RevocationData::Fresh(locator)))
+            .unwrap();
+    } else {
+        log::debug!("Not sending data to idle retrier ({tower_id}, {locator})")
+    }
+}
+
+/// Registers the client to a given tower.
+///
+/// Accepted tower_id formats:
+///     - tower_id@host:port
+///     - tower_id host port
+///     - tower_id@host (will default port to DEFAULT_PORT)
+///     - tower_id host (will default port to DEFAULT_PORT)
+async fn register(
+    plugin: Plugin<Arc<Mutex<WTClient>>>,
+    v: serde_json::Value,
+) -> Result<serde_json::Value, Error> {
+    let params = RegisterParams::try_from(v).map_err(|x| anyhow!(x))?;
+    let mut host = params.host.unwrap_or_else(|| "localhost".to_owned());
+    let tower_id = params.tower_id;
+    let user_id = plugin.state().lock().unwrap().user_id;
+
+    // TODO: The user should pick the start_time or, at least, check the returned start time against it's known block height.
+    // Otherwise the tower could just generate a subscription starting far in the future. For this we need to access lightning RPC
+    // which is not available in the current version of `cln-plugin` (but already on master). Add it for the next release.
+
+    let port = params.port.unwrap_or(
+        u16::try_from(plugin.option(&WT_PORT_CONFG).unwrap())
+            .map_err(|_| anyhow!("{} out of range", constants::WT_PORT))?,
+    );
+
+    let tower_net_addr = {
+        if !host.starts_with("http://") && !host.starts_with("https://") {
+            host = format!("http://{host}")
+        }
+        NetAddr::new(format!("{host}:{port}"))
+    };
+
+    let proxy = plugin.state().lock().unwrap().proxy.clone();
+
+    let receipt = http::register(tower_id, user_id, &tower_net_addr, &proxy)
+        .await
+        .map_err(|e| {
+            let mut state = plugin.state().lock().unwrap();
+            if e.is_connection() && state.towers.contains_key(&tower_id) {
+                state.set_tower_status(tower_id, TowerStatus::TemporaryUnreachable);
+            }
+            to_cln_error(e)
+        })?;
+
+    if !receipt.verify(&tower_id) {
+        return Err(anyhow!(
+            "Registration receipt contains bad signature. Are you using the right tower_id?"
+        ));
+    }
+
+    plugin
+        .state()
+        .lock()
+        .unwrap()
+        .add_update_tower(tower_id, tower_net_addr.net_addr(), &receipt).map_err(|e| {
+            if e.is_expiry() {
+                anyhow!("Registration receipt contains a subscription expiry that is not higher than the one we are currently registered for")
+            } else {
+                anyhow!("Registration receipt does not contain more slots than the ones we are currently registered for")
+            }
+        })?;
+
+    log::info!(
+        "Registration succeeded. Available slots: {}. Subscription period (block height range): ({}-{})",
+        receipt.available_slots(),
+        receipt.subscription_start(),
+        receipt.subscription_expiry()
+    );
+
+    Ok(json!(receipt))
+}
+
+/// Gets the latest registration receipt from the client to a given tower (if it exists).
+///
+/// This is pulled from the database
+async fn get_registration_receipt(
+    plugin: Plugin<Arc<Mutex<WTClient>>>,
+    v: serde_json::Value,
+) -> Result<serde_json::Value, Error> {
+    let tower_id = TowerId::try_from(v).map_err(|x| anyhow!(x))?;
+    let state = plugin.state().lock().unwrap();
+
+    if let Some(response) = state.get_registration_receipt(tower_id) {
+        Ok(json!(response))
+    } else {
+        Err(anyhow!(
+            "Cannot find {tower_id} within the known towers. Have you registered?"
+        ))
+    }
+}
+
+/// Gets the subscription information directly form the tower.
+async fn get_subscription_info(
+    plugin: Plugin<Arc<Mutex<WTClient>>>,
+    v: serde_json::Value,
+) -> Result<serde_json::Value, Error> {
+    let tower_id = TowerId::try_from(v).map_err(|x| anyhow!(x))?;
+
+    let (user_sk, tower_net_addr, proxy) = {
+        let state = plugin.state().lock().unwrap();
+        if let Some(info) = state.towers.get(&tower_id) {
+            Ok((state.user_sk, info.net_addr.clone(), state.proxy.clone()))
+        } else {
+            Err(anyhow!("Unknown tower id: {tower_id}"))
+        }
+    }?;
+
+    let signature = cryptography::sign("get subscription info".as_bytes(), &user_sk);
+
+    let response: common_msgs::GetSubscriptionInfoResponse = process_post_response(
+        post_request(
+            &tower_net_addr,
+            Endpoint::GetSubscriptionInfo,
+            &common_msgs::GetSubscriptionInfoRequest { signature },
+            &proxy,
+        )
+        .await,
+    )
+    .await
+    .map_err(|e| {
+        if e.is_connection() {
+            plugin
+                .state()
+                .lock()
+                .unwrap()
+                .set_tower_status(tower_id, TowerStatus::TemporaryUnreachable);
+        }
+        to_cln_error(e)
+    })?;
+
+    Ok(json!(response))
+}
+
+/// Gets information about an appointment from the tower.
+async fn get_appointment(
+    plugin: Plugin<Arc<Mutex<WTClient>>>,
+    v: serde_json::Value,
+) -> Result<serde_json::Value, Error> {
+    let params = GetAppointmentParams::try_from(v).map_err(|x| anyhow!(x))?;
+
+    let (user_sk, tower_net_addr, proxy) = {
+        let state = plugin.state().lock().unwrap();
+        if let Some(info) = state.towers.get(&params.tower_id) {
+            Ok((state.user_sk, info.net_addr.clone(), state.proxy.clone()))
+        } else {
+            Err(anyhow!("Unknown tower id: {}", params.tower_id))
+        }
+    }?;
+
+    let signature = cryptography::sign(
+        format!("get appointment {}", params.locator).as_bytes(),
+        &user_sk,
+    );
+
+    let response: ApiResponse<common_msgs::GetAppointmentResponse> = process_post_response(
+        post_request(
+            &tower_net_addr,
+            Endpoint::GetAppointment,
+            &common_msgs::GetAppointmentRequest {
+                locator: params.locator.to_vec(),
+                signature,
+            },
+            &proxy,
+        )
+        .await,
+    )
+    .await
+    .map_err(|e| {
+        if e.is_connection() {
+            plugin
+                .state()
+                .lock()
+                .unwrap()
+                .set_tower_status(params.tower_id, TowerStatus::TemporaryUnreachable);
+        }
+        to_cln_error(e)
+    })?;
+
+    Ok(json!(response))
+}
+
+/// Gets an appointment receipt from the client given a tower_id and a locator (if it exists).
+///
+/// This is pulled from the database
+async fn get_appointment_receipt(
+    plugin: Plugin<Arc<Mutex<WTClient>>>,
+    v: serde_json::Value,
+) -> Result<serde_json::Value, Error> {
+    let params = GetAppointmentParams::try_from(v).map_err(|x| anyhow!(x))?;
+    let state = plugin.state().lock().unwrap();
+
+    if let Some(r) = state.get_appointment_receipt(params.tower_id, params.locator) {
+        Ok(json!(r))
+    } else if state.towers.contains_key(&params.tower_id) {
+        Err(anyhow!(
+            "Cannot find {} within {}. Did you send that appointment?",
+            params.locator,
+            params.tower_id
+        ))
+    } else {
+        Err(anyhow!(
+            "Cannot find {} within the known towers. Have you registered?",
+            params.tower_id
+        ))
+    }
+}
+
+/// Lists all the registered towers.
+///
+/// The given information comes from memory, so it is summarized.
+async fn list_towers(
+    plugin: Plugin<Arc<Mutex<WTClient>>>,
+    _: serde_json::Value,
+) -> Result<serde_json::Value, Error> {
+    Ok(json!(plugin.state().lock().unwrap().towers))
+}
+
+/// Gets information about a given tower.
+///
+/// Data comes from disk (DB), so all stored data is provided.
+async fn get_tower_info(
+    plugin: Plugin<Arc<Mutex<WTClient>>>,
+    v: serde_json::Value,
+) -> Result<serde_json::Value, Error> {
+    let state = plugin.state().lock().unwrap();
+    let tower_id = TowerId::try_from(v).map_err(|e| anyhow!(e))?;
+
+    if let Some(tower_info) = state.load_tower_info(tower_id) {
+        // Notice we need to check the status in memory since we cannot distinguish between unreachable and temporary unreachable
+        // by just checking the data in the database.
+        Ok(json!(
+            tower_info.with_status(state.get_tower_status(&tower_id).unwrap())
+        ))
+    } else {
+        Err(anyhow!(
+            "Cannot find {tower_id} within the known towers. Have you registered?",
+        ))
+    }
+}
+
+async fn ping(
+    plugin: Plugin<Arc<Mutex<WTClient>>>,
+    v: serde_json::Value,
+) -> Result<serde_json::Value, Error> {
+    let (tower_net_addr, proxy) = {
+        // Check if the tower_id is known to the plugin
+        let tower_id = TowerId::try_from(v).map_err(|e| anyhow!(e))?;
+        let state = plugin.state().lock().unwrap();
+        (
+            state
+                .towers
+                .get(&tower_id)
+                .ok_or(anyhow!("Unknown tower_id"))?
+                .net_addr
+                .clone(),
+            state.proxy.clone(),
+        )
+    };
+    let response = get_request(&tower_net_addr, Endpoint::Ping, &proxy)
+        .await
+        .map_err(to_cln_error)?;
+
+    if response.status().is_success() {
+        Ok(json!("Tower is reachable"))
+    } else {
+        Err(anyhow!(format!(
+            "Tower cannot be reached (Error: {})",
+            response.status()
+        )))
+    }
+}
+
+/// Triggers a manual retry of a tower, tries to send all pending appointments to it.
+///
+/// Only works if the tower is unreachable or there's been a subscription error (and the tower is not already being retried).
+async fn retry_tower(
+    plugin: Plugin<Arc<Mutex<WTClient>>>,
+    v: serde_json::Value,
+) -> Result<serde_json::Value, Error> {
+    let tower_id = TowerId::try_from(v).map_err(|e| anyhow!(e))?;
+    let state = plugin.state().lock().unwrap();
+    if let Some(tower_status) = state.get_tower_status(&tower_id) {
+        if let Some(retrier_status) = state.retriers.get(&tower_id) {
+            if retrier_status.is_idle() {
+                // We don't send any associated data in this case given the idle retrier already has it all.
+                state
+                    .unreachable_towers
+                    .send((tower_id, RevocationData::None))
+                    .map_err(|e| anyhow!(e))?;
+            } else {
+                // Status can only be running or idle for data in the retriers map.
+                return Err(anyhow!("{tower_id} is already being retried"));
+            }
+        } else if tower_status.is_retryable() {
+            // We do send associated data here given there is no retrier associated to this tower.
+            state
+                .unreachable_towers
+                .send((
+                    tower_id,
+                    RevocationData::Stale(
+                        state
+                            .towers
+                            .get(&tower_id)
+                            .unwrap()
+                            .pending_appointments
+                            .iter()
+                            .cloned()
+                            .collect(),
+                    ),
+                ))
+                .map_err(|e| anyhow!(e))?;
+        } else {
+            return Err(anyhow!(
+                "Tower status must be unreachable or have a subscription issue to manually retry",
+            ));
+        }
+    } else {
+        return Err(anyhow!("Unknown tower {tower_id}"));
+    }
+    Ok(json!(format!("Retrying {tower_id}")))
+}
+
+/// Forgets about a tower wiping out all local data associated to it.
+async fn abandon_tower(
+    plugin: Plugin<Arc<Mutex<WTClient>>>,
+    v: serde_json::Value,
+) -> Result<serde_json::Value, Error> {
+    let tower_id = TowerId::try_from(v).map_err(|e| anyhow!(e))?;
+    let mut state = plugin.state().lock().unwrap();
+    if state.towers.contains_key(&tower_id) {
+        state.remove_tower(tower_id).unwrap();
+        Ok(json!(format!("{tower_id} successfully abandoned")))
+    } else {
+        Err(anyhow!("Unknown tower {tower_id}"))
+    }
+}
+
+/// Sends an appointment to all registered towers for every new commitment transaction.
+///
+/// The appointment is built using the data provided by the backend (dispute txid and penalty transaction).
+async fn on_commitment_revocation(
+    plugin: Plugin<Arc<Mutex<WTClient>>>,
+    v: serde_json::Value,
+) -> Result<serde_json::Value, Error> {
+    let commitment_revocation = serde_json::from_value::<CommitmentRevocation>(v)
+        .map_err(|e| anyhow!("Cannot decode commitment_revocation data. Error: {e}"))?;
+    log::debug!(
+        "New commitment revocation received for channel {}. Commit number {}",
+        commitment_revocation.channel_id,
+        commitment_revocation.commit_num
+    );
+
+    // TODO: For now, to_self_delay is hardcoded to 42. Revisit and define it better / remove it when / if needed
+    let locator = Locator::new(commitment_revocation.commitment_txid);
+    let appointment = Appointment::new(
+        locator,
+        cryptography::encrypt(
+            &commitment_revocation.penalty_tx,
+            &commitment_revocation.commitment_txid,
+        )
+        .unwrap(),
+        42,
+    );
+    let signature = cryptography::sign(
+        &appointment.to_vec(),
+        &plugin.state().lock().unwrap().user_sk,
+    );
+
+    // Looks like we cannot iterate through towers given a locked state is not Send (due to the async call),
+    // so we need to clone the bare minimum.
+    let towers = plugin
+        .state()
+        .lock()
+        .unwrap()
+        .towers
+        .iter()
+        .map(|(id, info)| (*id, info.net_addr.clone(), info.status))
+        .collect::<Vec<_>>();
+
+    let proxy = plugin.state().lock().unwrap().proxy.clone();
+
+    for (tower_id, net_addr, status) in towers {
+        if status.is_reachable() {
+            match http::add_appointment(tower_id, &net_addr, &proxy, &appointment, &signature).await
+            {
+                Ok((slots, receipt)) => {
+                    plugin
+                        .state()
+                        .lock()
+                        .unwrap()
+                        .add_appointment_receipt(tower_id, locator, slots, &receipt);
+                    log::debug!("Response verified and data stored in the database");
+                }
+                Err(e) => match e {
+                    AddAppointmentError::RequestError(e) => {
+                        if e.is_connection() {
+                            log::warn!(
+                                "{tower_id} cannot be reached. Adding {} to pending appointments",
+                                appointment.locator
+                            );
+                            let mut state = plugin.state().lock().unwrap();
+                            state.set_tower_status(tower_id, TowerStatus::TemporaryUnreachable);
+                            state.add_pending_appointment(tower_id, &appointment);
+                            send_to_retrier(&state, tower_id, appointment.locator);
+                        }
+                    }
+                    AddAppointmentError::ApiError(e) => match e.error_code {
+                        errors::INVALID_SIGNATURE_OR_SUBSCRIPTION_ERROR => {
+                            log::warn!(
+                                "There is a subscription issue with {tower_id}. Adding {} to pending",
+                                appointment.locator
+                            );
+                            let mut state = plugin.state().lock().unwrap();
+                            state.set_tower_status(tower_id, TowerStatus::SubscriptionError);
+                            state.add_pending_appointment(tower_id, &appointment);
+                            send_to_retrier(&state, tower_id, appointment.locator);
+                        }
+
+                        _ => {
+                            log::warn!(
+                                "{tower_id} rejected the appointment. Error: {}, error_code: {}",
+                                e.error,
+                                e.error_code
+                            );
+                            plugin
+                                .state()
+                                .lock()
+                                .unwrap()
+                                .add_invalid_appointment(tower_id, &appointment);
+                        }
+                    },
+                    AddAppointmentError::SignatureError(proof) => {
+                        log::warn!("Cannot recover known tower_id from the appointment receipt. Flagging tower as misbehaving");
+                        plugin
+                            .state()
+                            .lock()
+                            .unwrap()
+                            .flag_misbehaving_tower(tower_id, proof)
+                    }
+                },
+            };
+        } else if status.is_misbehaving() {
+            log::warn!("{tower_id} is misbehaving. Not sending any further appointments",);
+        } else {
+            if status.is_subscription_error() {
+                log::warn!(
+                    "There is a subscription issue with {tower_id}. Adding {} to pending",
+                    appointment.locator
+                );
+            } else {
+                log::warn!(
+                    "{tower_id} is {status}. Adding {} to pending",
+                    appointment.locator,
+                );
+            }
+
+            let mut state = plugin.state().lock().unwrap();
+            state.add_pending_appointment(tower_id, &appointment);
+
+            if !status.is_unreachable() {
+                send_to_retrier(&state, tower_id, appointment.locator);
+            }
+        }
+    }
+
+    // FIXME: Ask cdecker: Do hooks need to return something?
+    Ok(json!(r#" {"result": continue}"#))
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Error> {
+    let data_dir = match env::var(constants::TOWERS_DATA_DIR) {
+        Ok(v) => PathBuf::from(v),
+        Err(_) => home_dir().unwrap().join(constants::DEFAULT_TOWERS_DATA_DIR),
+    };
+
+    let builder = Builder::new(stdin(), stdout())
+        .option(WT_PORT_CONFG)
+        .option(WT_MAX_RETRY_TIME_CONFIG)
+        .option(WT_AUTO_RETRY_DELAY_CONFIG)
+        .option(DEV_WT_MAX_RETRY_INTERVAL_CONFIG)
+        .rpcmethod(
+            constants::RPC_REGISTER_TOWER,
+            constants::RPC_REGISTER_TOWER_DESC,
+            register,
+        )
+        .rpcmethod(
+            constants::RPC_GET_REGISTRATION_RECEIPT,
+            constants::RPC_GET_REGISTRATION_RECEIPT_DESC,
+            get_registration_receipt,
+        )
+        .rpcmethod(
+            constants::RPC_GET_APPOINTMENT,
+            constants::RPC_GET_APPOINTMENT_DESC,
+            get_appointment,
+        )
+        .rpcmethod(
+            constants::RPC_GET_APPOINTMENT_RECEIPT,
+            constants::RPC_GET_APPOINTMENT_RECEIPT_DESC,
+            get_appointment_receipt,
+        )
+        .rpcmethod(
+            constants::RPC_GET_SUBSCRIPTION_INFO,
+            constants::RPC_GET_SUBSCRIPTION_INFO_DESC,
+            get_subscription_info,
+        )
+        .rpcmethod(
+            constants::RPC_LIST_TOWERS,
+            constants::RPC_LIST_TOWERS_DESC,
+            list_towers,
+        )
+        .rpcmethod(
+            constants::RPC_GET_TOWER_INFO,
+            constants::RPC_GET_TOWER_INFO_DESC,
+            get_tower_info,
+        )
+        .rpcmethod(constants::RPC_PING, constants::RPC_PING_DESC, ping)
+        .rpcmethod(
+            constants::RPC_RETRY_TOWER,
+            constants::RPC_RETRY_TOWER_DESC,
+            retry_tower,
+        )
+        .rpcmethod(
+            constants::RPC_ABANDON_TOWER,
+            constants::RPC_ABANDON_TOWER_DESC,
+            abandon_tower,
+        )
+        .hook(
+            constants::HOOK_COMMITMENT_REVOCATION,
+            on_commitment_revocation,
+        );
+
+    // We're unwrapping here given it does not seem we actually have anything to check at the moment.
+    // Change this so the plugin can be disabled soon if this happens not to be the case.
+    let midstate = if let Some(midstate) = builder.configure().await? {
+        midstate
+    } else {
+        return Ok(());
+    };
+
+    let (tx, rx) = unbounded_channel();
+    let wt_client = Arc::new(Mutex::new(
+        WTClient::with_proxy(
+            data_dir,
+            tx,
+            midstate.configuration().proxy.map(|proxy| {
+                // We don't need to inform `always-use-proxy` needing `proxy` to work. This is done by CLN already when needed.
+                ProxyInfo::new(
+                    proxy,
+                    midstate.configuration().always_use_proxy.unwrap_or(false),
+                )
+            }),
+        )
+        .await,
+    ));
+
+    let max_elapsed_time = u16::try_from(midstate.option(&WT_MAX_RETRY_TIME_CONFIG).unwrap())
+        .inspect_err(|_| {
+            log::error!("{} out of range", constants::WT_MAX_RETRY_TIME);
+        })?;
+
+    let auto_retry_delay = u32::try_from(midstate.option(&WT_AUTO_RETRY_DELAY_CONFIG).unwrap())
+        .inspect_err(|_| {
+            log::error!("{} out of range", constants::WT_AUTO_RETRY_DELAY);
+        })?;
+
+    let max_interval_time = u16::try_from(
+        midstate.option(&DEV_WT_MAX_RETRY_INTERVAL_CONFIG).unwrap(),
+    )
+    .inspect_err(|_| {
+        log::error!("{} out of range", constants::DEV_WT_MAX_RETRY_INTERVAL);
+    })?;
+
+    let plugin = midstate.start(wt_client.clone()).await?;
+    tokio::spawn(async move {
+        RetryManager::new(
+            wt_client,
+            rx,
+            max_elapsed_time,
+            auto_retry_delay,
+            max_interval_time,
+        )
+        .manage_retry()
+        .await
+    });
+    plugin.join().await
+}

watchtower-plugin/src/net/http.rs

@@ -0,0 +1,687 @@
+use reqwest::{Method, Response};
+use serde::{de::DeserializeOwned, Deserialize, Serialize};
+
+use teos_common::appointment::Appointment;
+use teos_common::cryptography;
+use teos_common::net::http::Endpoint;
+use teos_common::net::NetAddr;
+use teos_common::protos as common_msgs;
+use teos_common::receipts::{AppointmentReceipt, RegistrationReceipt};
+use teos_common::{TowerId, UserId};
+
+use crate::net::ProxyInfo;
+use crate::MisbehaviorProof;
+
+/// Represents a generic api response.
+#[derive(Serialize, Deserialize, Debug)]
+#[serde(untagged)]
+pub enum ApiResponse<T> {
+    Response(T),
+    Error(ApiError),
+}
+
+/// API errors that can be received when interacting with the tower. Error codes match `teos_common::errors`.
+#[derive(Serialize, Deserialize, Debug)]
+pub struct ApiError {
+    pub error: String,
+    pub error_code: u8,
+}
+
+/// Errors related to requests sent to the tower.
+#[derive(Debug, PartialEq, Eq)]
+pub enum RequestError {
+    ConnectionError(String),
+    DeserializeError(String),
+    Unexpected(String),
+}
+
+impl RequestError {
+    pub fn is_connection(&self) -> bool {
+        matches!(self, RequestError::ConnectionError(_))
+    }
+}
+
+/// Errors related to the `add_appointment` requests to the tower.
+#[derive(Debug)]
+pub enum AddAppointmentError {
+    RequestError(RequestError),
+    ApiError(ApiError),
+    SignatureError(MisbehaviorProof),
+}
+
+impl From<RequestError> for AddAppointmentError {
+    fn from(r: RequestError) -> Self {
+        AddAppointmentError::RequestError(r)
+    }
+}
+
+/// Handles the logic of interacting with the `register` endpoint of the tower.
+pub async fn register(
+    tower_id: TowerId,
+    user_id: UserId,
+    tower_net_addr: &NetAddr,
+    proxy: &Option<ProxyInfo>,
+) -> Result<RegistrationReceipt, RequestError> {
+    log::info!("Registering in the Eye of Satoshi (tower_id={tower_id})");
+    process_post_response(
+        post_request(
+            tower_net_addr,
+            Endpoint::Register,
+            &common_msgs::RegisterRequest {
+                user_id: user_id.to_vec(),
+            },
+            proxy,
+        )
+        .await,
+    )
+    .await
+    .map(|r: common_msgs::RegisterResponse| {
+        RegistrationReceipt::with_signature(
+            user_id,
+            r.available_slots,
+            r.subscription_start,
+            r.subscription_expiry,
+            r.subscription_signature,
+        )
+    })
+}
+
+/// Encapsulates the logging and response parsing of sending and appointment to the tower.
+pub async fn add_appointment(
+    tower_id: TowerId,
+    tower_net_addr: &NetAddr,
+    proxy: &Option<ProxyInfo>,
+    appointment: &Appointment,
+    signature: &str,
+) -> Result<(u32, AppointmentReceipt), AddAppointmentError> {
+    log::debug!(
+        "Sending appointment {} to tower {tower_id}",
+        appointment.locator
+    );
+    let (response, receipt) =
+        send_appointment(tower_id, tower_net_addr, proxy, appointment, signature).await?;
+    log::debug!("Appointment accepted and signed by {tower_id}");
+    log::debug!("Remaining slots: {}", response.available_slots);
+    log::debug!("Start block: {}", response.start_block);
+
+    Ok((response.available_slots, receipt))
+}
+
+/// Handles the logic of interacting with the `add_appointment` endpoint of the tower.
+pub async fn send_appointment(
+    tower_id: TowerId,
+    tower_net_addr: &NetAddr,
+    proxy: &Option<ProxyInfo>,
+    appointment: &Appointment,
+    signature: &str,
+) -> Result<(common_msgs::AddAppointmentResponse, AppointmentReceipt), AddAppointmentError> {
+    let request_data = common_msgs::AddAppointmentRequest {
+        appointment: Some(appointment.clone().into()),
+        signature: signature.to_owned(),
+    };
+
+    match process_post_response(
+        post_request(
+            tower_net_addr,
+            Endpoint::AddAppointment,
+            &request_data,
+            proxy,
+        )
+        .await,
+    )
+    .await?
+    {
+        ApiResponse::Response::<common_msgs::AddAppointmentResponse>(r) => {
+            let receipt = AppointmentReceipt::with_signature(
+                signature.to_owned(),
+                r.start_block,
+                r.signature.clone(),
+            );
+            let recovered_id = TowerId(
+                cryptography::recover_pk(&receipt.to_vec(), &receipt.signature().unwrap()).unwrap(),
+            );
+            if recovered_id == tower_id {
+                Ok((r, receipt))
+            } else {
+                Err(AddAppointmentError::SignatureError(MisbehaviorProof::new(
+                    appointment.locator,
+                    receipt,
+                    recovered_id,
+                )))
+            }
+        }
+        ApiResponse::Error(e) => Err(AddAppointmentError::ApiError(e)),
+    }
+}
+
+/// A generic function to send a request to a tower.
+async fn request<S: Serialize>(
+    tower_net_addr: &NetAddr,
+    endpoint: Endpoint,
+    proxy: &Option<ProxyInfo>,
+    method: Method,
+    data: Option<S>,
+) -> Result<Response, RequestError> {
+    let client = if let Some(proxy) = proxy {
+        if proxy.always_use || tower_net_addr.is_onion() {
+            reqwest::Client::builder()
+                .proxy(
+                    reqwest::Proxy::http(proxy.get_socks_addr())
+                        .map_err(|e| RequestError::ConnectionError(format!("{e}")))?,
+                )
+                .build()
+                .map_err(|e| RequestError::ConnectionError(format!("{e}")))?
+        } else {
+            reqwest::Client::new()
+        }
+    } else {
+        // If there is no proxy we only build the client as long as the address is not onion
+        if tower_net_addr.is_onion() {
+            return Err(RequestError::ConnectionError(
+                "Cannot connect to an onion address without a proxy".to_owned(),
+            ));
+        }
+        reqwest::Client::new()
+    };
+
+    let mut request_builder = client.request(
+        method,
+        format!("{}{}", tower_net_addr.net_addr(), endpoint.path()),
+    );
+
+    if let Some(data) = data {
+        request_builder = request_builder.json(&data);
+    }
+
+    request_builder.send().await.map_err(|e| {
+        log::debug!("An error ocurred when sending data to the tower: {e}");
+        if e.is_connect() | e.is_timeout() {
+            RequestError::ConnectionError(
+                "Cannot connect to the tower. Connection refused".to_owned(),
+            )
+        } else {
+            RequestError::Unexpected("Unexpected error ocurred (see logs for more info)".to_owned())
+        }
+    })
+}
+
+pub async fn post_request<S: Serialize>(
+    tower_net_addr: &NetAddr,
+    endpoint: Endpoint,
+    data: S,
+    proxy: &Option<ProxyInfo>,
+) -> Result<Response, RequestError> {
+    request(tower_net_addr, endpoint, proxy, Method::POST, Some(data)).await
+}
+
+pub async fn get_request(
+    tower_net_addr: &NetAddr,
+    endpoint: Endpoint,
+    proxy: &Option<ProxyInfo>,
+) -> Result<Response, RequestError> {
+    request::<()>(tower_net_addr, endpoint, proxy, Method::GET, None).await
+}
+
+/// Generic function to process the response of a given post request.
+pub async fn process_post_response<T: DeserializeOwned>(
+    post_request: Result<Response, RequestError>,
+) -> Result<T, RequestError> {
+    // TODO: Check if this can be switched for a map. Not sure how to handle async with maps
+    match post_request {
+        Ok(r) => r.json().await.map_err(|e| {
+            RequestError::DeserializeError(format!("Unexpected response body. Error: {e}"))
+        }),
+        Err(e) => Err(e),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+
+    use crate::test_utils::get_dummy_add_appointment_response;
+    use teos_common::test_utils::{
+        generate_random_appointment, get_random_appointment_receipt,
+        get_random_registration_receipt, get_random_user_id,
+    };
+
+    mod request_error {
+        use super::*;
+
+        #[test]
+        fn test_is_connection() {
+            let error_message = "error_msg";
+            for error in [
+                RequestError::ConnectionError(error_message.to_owned()),
+                RequestError::DeserializeError(error_message.to_owned()),
+                RequestError::Unexpected(error_message.to_owned()),
+            ] {
+                if error == RequestError::ConnectionError(error_message.to_owned()) {
+                    assert!(error.is_connection())
+                } else {
+                    assert!(!error.is_connection())
+                }
+            }
+        }
+    }
+
+    #[tokio::test]
+    async fn test_register() {
+        let (tower_sk, tower_pk) = cryptography::get_random_keypair();
+        let mut registration_receipt = get_random_registration_receipt();
+        registration_receipt.sign(&tower_sk);
+
+        let mut server = mockito::Server::new_async().await;
+        let api_mock = server
+            .mock("POST", Endpoint::Register.path().as_str())
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .with_body(json!(registration_receipt).to_string())
+            .create_async()
+            .await;
+
+        let receipt = register(
+            TowerId(tower_pk),
+            registration_receipt.user_id(),
+            &NetAddr::new(server.url()),
+            &None,
+        )
+        .await
+        .unwrap();
+
+        api_mock.assert_async().await;
+        assert_eq!(receipt, registration_receipt);
+    }
+
+    #[tokio::test]
+    async fn test_register_connection_error() {
+        let error = register(
+            get_random_user_id(),
+            get_random_user_id(),
+            &NetAddr::new("http://server_addr".to_owned()),
+            &None,
+        )
+        .await
+        .unwrap_err();
+
+        assert!(matches!(error, RequestError::ConnectionError { .. }))
+    }
+
+    #[tokio::test]
+    async fn test_register_deserialize_error() {
+        let mut server = mockito::Server::new_async().await;
+        let api_mock = server
+            .mock("POST", Endpoint::Register.path().as_str())
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .with_body(json!([]).to_string())
+            .create_async()
+            .await;
+
+        let error = register(
+            get_random_user_id(),
+            get_random_user_id(),
+            &NetAddr::new(server.url()),
+            &None,
+        )
+        .await
+        .unwrap_err();
+
+        api_mock.assert_async().await;
+        assert!(matches!(error, RequestError::DeserializeError { .. }))
+    }
+
+    #[tokio::test]
+    async fn test_add_appointment() {
+        // `add_appointment` is basically a pass trough function for `send_appointment` with some logging and a parse of the outputs
+        // in case there are no errors. All the error cases will be tested in `send_appointment`.
+        let (tower_sk, tower_pk) = cryptography::get_random_keypair();
+        let appointment = generate_random_appointment(None);
+
+        let appointment_receipt = get_random_appointment_receipt(tower_sk);
+        let add_appointment_response =
+            get_dummy_add_appointment_response(appointment.locator, &appointment_receipt);
+
+        let mut server = mockito::Server::new_async().await;
+        let api_mock = server
+            .mock("POST", Endpoint::AddAppointment.path().as_str())
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .with_body(json!(add_appointment_response).to_string())
+            .create_async()
+            .await;
+
+        let (response, receipt) = add_appointment(
+            TowerId(tower_pk),
+            &NetAddr::new(server.url()),
+            &None,
+            &appointment,
+            appointment_receipt.user_signature(),
+        )
+        .await
+        .unwrap();
+
+        api_mock.assert_async().await;
+        assert_eq!(response, add_appointment_response.available_slots);
+        assert_eq!(receipt, appointment_receipt);
+    }
+
+    #[tokio::test]
+    async fn test_send_appointment() {
+        let (tower_sk, tower_pk) = cryptography::get_random_keypair();
+        let appointment = generate_random_appointment(None);
+
+        let appointment_receipt = get_random_appointment_receipt(tower_sk);
+        let add_appointment_response =
+            get_dummy_add_appointment_response(appointment.locator, &appointment_receipt);
+
+        let mut server = mockito::Server::new_async().await;
+        let api_mock = server
+            .mock("POST", Endpoint::AddAppointment.path().as_str())
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .with_body(json!(add_appointment_response).to_string())
+            .create_async()
+            .await;
+
+        let (response, receipt) = send_appointment(
+            TowerId(tower_pk),
+            &NetAddr::new(server.url()),
+            &None,
+            &appointment,
+            appointment_receipt.user_signature(),
+        )
+        .await
+        .unwrap();
+
+        api_mock.assert_async().await;
+        assert_eq!(response, add_appointment_response);
+        assert_eq!(receipt, appointment_receipt);
+    }
+
+    #[tokio::test]
+    async fn test_send_appointment_misbehaving() {
+        let (sybil_tower_sk, sibyl_tower_pk) = cryptography::get_random_keypair();
+        let appointment = generate_random_appointment(None);
+
+        let appointment_receipt = get_random_appointment_receipt(sybil_tower_sk);
+        let add_appointment_response =
+            get_dummy_add_appointment_response(appointment.locator, &appointment_receipt);
+
+        let mut server = mockito::Server::new_async().await;
+        let api_mock = server
+            .mock("POST", Endpoint::AddAppointment.path().as_str())
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .with_body(json!(add_appointment_response).to_string())
+            .create_async()
+            .await;
+
+        let tower_id = get_random_user_id();
+        let error = send_appointment(
+            tower_id,
+            &NetAddr::new(server.url()),
+            &None,
+            &appointment,
+            appointment_receipt.user_signature(),
+        )
+        .await
+        .unwrap_err();
+
+        api_mock.assert_async().await;
+        if let AddAppointmentError::SignatureError(proof) = error {
+            assert_eq!(
+                MisbehaviorProof::new(
+                    appointment.locator,
+                    appointment_receipt,
+                    TowerId(sibyl_tower_pk)
+                ),
+                proof
+            )
+        } else {
+            panic!("SignatureError was expected")
+        }
+    }
+
+    #[tokio::test]
+    async fn test_send_appointment_connection_error() {
+        let error = send_appointment(
+            get_random_user_id(),
+            &NetAddr::new("http://server_addr".to_owned()),
+            &None,
+            &generate_random_appointment(None),
+            "user_sig",
+        )
+        .await
+        .unwrap_err();
+
+        if let AddAppointmentError::RequestError(e) = error {
+            assert!(matches!(e, RequestError::ConnectionError { .. }))
+        } else {
+            panic!("ConnectionError was expected")
+        }
+    }
+
+    #[tokio::test]
+    async fn test_send_appointment_deserialize_error() {
+        let mut server = mockito::Server::new_async().await;
+        let api_mock = server
+            .mock("POST", Endpoint::AddAppointment.path().as_str())
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .with_body(json!([]).to_string())
+            .create_async()
+            .await;
+
+        let error = send_appointment(
+            get_random_user_id(),
+            &NetAddr::new(server.url()),
+            &None,
+            &generate_random_appointment(None),
+            "user_sig",
+        )
+        .await
+        .unwrap_err();
+
+        api_mock.assert_async().await;
+        if let AddAppointmentError::RequestError(e) = error {
+            assert!(matches!(e, RequestError::DeserializeError { .. }))
+        } else {
+            panic!("DeserializeError was expected")
+        }
+    }
+
+    #[tokio::test]
+    async fn test_send_appointment_api_error() {
+        let api_error = ApiError {
+            error: "error_msg".to_owned(),
+            error_code: 1,
+        };
+
+        let mut server = mockito::Server::new_async().await;
+        let api_mock = server
+            .mock("POST", Endpoint::AddAppointment.path().as_str())
+            .with_status(400)
+            .with_header("content-type", "application/json")
+            .with_body(json!(api_error).to_string())
+            .create_async()
+            .await;
+
+        let error = send_appointment(
+            get_random_user_id(),
+            &NetAddr::new(server.url()),
+            &None,
+            &generate_random_appointment(None),
+            "user_sig",
+        )
+        .await
+        .unwrap_err();
+
+        api_mock.assert_async().await;
+        assert!(matches!(error, AddAppointmentError::ApiError { .. }));
+    }
+
+    #[tokio::test]
+    async fn test_request() {
+        let mut server = mockito::Server::new_async().await;
+
+        // Test with POST
+        let api_mock_post = server
+            .mock("POST", Endpoint::Register.path().as_str())
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .create_async()
+            .await;
+
+        let response_post = request(
+            &NetAddr::new(server.url()),
+            Endpoint::Register,
+            &None,
+            Method::POST,
+            Some(json!("")),
+        )
+        .await;
+
+        api_mock_post.assert_async().await;
+        assert!(matches!(response_post, Ok(Response { .. })));
+
+        // Test with GET
+        let api_mock_get = server
+            .mock("GET", Endpoint::Ping.path().as_str())
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .create_async()
+            .await;
+
+        let response_get = request::<()>(
+            &NetAddr::new(server.url()),
+            Endpoint::Ping,
+            &None,
+            Method::GET,
+            None,
+        )
+        .await;
+
+        api_mock_get.assert_async().await;
+        assert!(matches!(response_get, Ok(Response { .. })));
+    }
+
+    #[tokio::test]
+    async fn test_request_connection_error() {
+        assert!(request(
+            &NetAddr::new("http://unreachable_url".to_owned()),
+            Endpoint::Register,
+            &None,
+            Method::POST,
+            Some(json!("")),
+        )
+        .await
+        .unwrap_err()
+        .is_connection());
+
+        assert!(request(
+            &NetAddr::new("http://unreachable_url".to_owned()),
+            Endpoint::Ping,
+            &None,
+            Method::GET,
+            None::<&str>,
+        )
+        .await
+        .unwrap_err()
+        .is_connection());
+    }
+
+    #[tokio::test]
+    async fn test_get_request() {
+        let mut server = mockito::Server::new_async().await;
+        let api_mock = server
+            .mock("GET", Endpoint::Ping.path().as_str())
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .create_async()
+            .await;
+        let response = get_request(&NetAddr::new(server.url()), Endpoint::Ping, &None).await;
+
+        api_mock.assert_async().await;
+
+        assert!(matches!(response, Ok(Response { .. })));
+    }
+
+    #[tokio::test]
+    async fn test_get_request_connection_error() {
+        assert!(get_request(
+            &NetAddr::new("http://unreachable_url".to_owned()),
+            Endpoint::Ping,
+            &None,
+        )
+        .await
+        .unwrap_err()
+        .is_connection());
+    }
+
+    #[tokio::test]
+    async fn test_post_request() {
+        let mut server = mockito::Server::new_async().await;
+        let api_mock = server
+            .mock("POST", Endpoint::Register.path().as_str())
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .create_async()
+            .await;
+
+        let response = post_request(
+            &NetAddr::new(server.url()),
+            Endpoint::Register,
+            json!(""),
+            &None,
+        )
+        .await;
+
+        api_mock.assert_async().await;
+        assert!(matches!(response, Ok(Response { .. })));
+    }
+
+    #[tokio::test]
+    async fn test_post_request_connection_error() {
+        assert!(post_request(
+            &NetAddr::new("http://unreachable_url".to_owned()),
+            Endpoint::Register,
+            json!(""),
+            &None,
+        )
+        .await
+        .unwrap_err()
+        .is_connection());
+    }
+
+    #[tokio::test]
+    async fn test_process_post_response_json_error() {
+        // `process_post_response` is a pass-trough function that maps json deserialization errors from `post_request`.
+        // So just testing that specific case should be enough.
+
+        let mut server = mockito::Server::new_async().await;
+        let api_mock = server
+            .mock("POST", Endpoint::GetAppointment.path().as_str())
+            .with_status(200)
+            .with_header("content-type", "application/json")
+            .create_async()
+            .await;
+
+        // Any expected response work here as long as it cannot be properly deserialized
+        let error = process_post_response::<ApiResponse<common_msgs::GetAppointmentResponse>>(
+            post_request(
+                &NetAddr::new(server.url()),
+                Endpoint::GetAppointment,
+                json!(""),
+                &None,
+            )
+            .await,
+        )
+        .await
+        .unwrap_err();
+
+        api_mock.assert_async().await;
+        assert!(matches!(error, RequestError::DeserializeError { .. }));
+    }
+}

watchtower-plugin/src/net/mod.rs

@@ -0,0 +1,25 @@
+use cln_plugin::messages;
+use serde::Deserialize;
+pub mod http;
+
+#[derive(Clone, Debug, Deserialize)]
+pub struct ProxyInfo {
+    #[serde(flatten)]
+    /// The proxy data
+    inner: messages::ProxyInfo,
+    /// Whether to only send data though Tor or not
+    pub always_use: bool,
+}
+
+impl ProxyInfo {
+    pub fn new(proxy: messages::ProxyInfo, always_use: bool) -> Self {
+        Self {
+            inner: proxy,
+            always_use,
+        }
+    }
+
+    pub fn get_socks_addr(&self) -> String {
+        format!("socks5h://{}:{}", self.inner.address, self.inner.port)
+    }
+}

watchtower-plugin/src/ser.rs

@@ -0,0 +1,70 @@
+use bitcoin::consensus::encode;
+use bitcoin::Transaction;
+
+use teos_common::appointment::{Appointment, Locator};
+
+use hex::FromHex;
+use serde::{de, ser::SerializeMap, Deserializer, Serialize, Serializer};
+use std::collections::HashMap;
+
+pub fn deserialize_tx<'de, D>(deserializer: D) -> Result<Transaction, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    struct TransactionVisitor;
+
+    impl<'de> de::Visitor<'de> for TransactionVisitor {
+        type Value = Transaction;
+
+        fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+            formatter.write_str("a hex string containing the transaction")
+        }
+
+        fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+        where
+            E: de::Error,
+        {
+            let tx = encode::deserialize(
+                &Vec::from_hex(v).map_err(|_| E::custom("transaction is not hex encoded"))?,
+            )
+            .map_err(|_| E::custom("transaction cannot be deserialized"))?;
+            Ok(tx)
+        }
+    }
+
+    deserializer.deserialize_any(TransactionVisitor)
+}
+
+pub fn serialize_receipts<S>(hm: &HashMap<Locator, String>, s: S) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+{
+    let mut map = s.serialize_map(Some(hm.len()))?;
+    for (locator, sig) in hm {
+        map.serialize_entry(&hex::encode(locator), sig)?;
+    }
+    map.end()
+}
+
+#[derive(Serialize)]
+struct AppointmentInners {
+    encrypted_blob: String,
+    to_self_delay: u32,
+}
+
+pub fn serialize_appointments<S>(v: &Vec<Appointment>, s: S) -> Result<S::Ok, S::Error>
+where
+    S: Serializer,
+{
+    let mut map = s.serialize_map(Some(v.len()))?;
+    for a in v {
+        map.serialize_entry(
+            &hex::encode(a.locator),
+            &AppointmentInners {
+                encrypted_blob: hex::encode(&a.encrypted_blob),
+                to_self_delay: a.to_self_delay,
+            },
+        )?;
+    }
+    map.end()
+}

watchtower-plugin/src/test_utils.rs

@@ -0,0 +1,16 @@
+use teos_common::appointment::Locator;
+use teos_common::protos as common_msgs;
+use teos_common::receipts::AppointmentReceipt;
+
+pub fn get_dummy_add_appointment_response(
+    locator: Locator,
+    receipt: &AppointmentReceipt,
+) -> common_msgs::AddAppointmentResponse {
+    common_msgs::AddAppointmentResponse {
+        locator: locator.to_vec(),
+        start_block: receipt.start_block(),
+        signature: receipt.signature().unwrap(),
+        available_slots: 21,
+        subscription_expiry: 1000,
+    }
+}

watchtower-plugin/src/wt_client.rs

@@ -0,0 +1,901 @@
+use std::collections::{HashMap, HashSet};
+use std::iter::FromIterator;
+use std::path::PathBuf;
+use tokio::fs;
+use tokio::sync::mpsc::UnboundedSender;
+
+use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
+
+use teos_common::appointment::{Appointment, Locator};
+use teos_common::cryptography;
+use teos_common::dbm::Error as DBError;
+use teos_common::receipts::{AppointmentReceipt, RegistrationReceipt};
+use teos_common::{TowerId, UserId};
+
+use crate::dbm::DBM;
+use crate::net::ProxyInfo;
+use crate::retrier::RetrierStatus;
+use crate::{MisbehaviorProof, SubscriptionError, TowerInfo, TowerStatus, TowerSummary};
+
+#[derive(Eq, PartialEq)]
+pub enum RevocationData {
+    Fresh(Locator),
+    Stale(HashSet<Locator>),
+    None,
+}
+
+impl RevocationData {
+    pub fn is_none(&self) -> bool {
+        *self == RevocationData::None
+    }
+}
+
+impl From<RevocationData> for HashSet<Locator> {
+    fn from(r: RevocationData) -> Self {
+        match r {
+            RevocationData::Fresh(l) => HashSet::from_iter(vec![l]),
+            RevocationData::Stale(hs) => hs,
+            RevocationData::None => HashSet::new(),
+        }
+    }
+}
+
+impl std::fmt::Debug for RevocationData {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(
+            f,
+            "{}",
+            match self {
+                RevocationData::Fresh(l) => format!("Fresh: {l}"),
+                RevocationData::Stale(hs) => format!(
+                    "Stale: {:?}",
+                    hs.iter().map(|l| l.to_string()).collect::<Vec<_>>()
+                ),
+                RevocationData::None => "None".to_owned(),
+            }
+        )
+    }
+}
+
+/// Represents the watchtower client that is being used as the CoreLN plugin state.
+pub struct WTClient {
+    /// A [DBM] instance.
+    pub dbm: DBM,
+    /// A collection of towers the client is registered to.
+    pub towers: HashMap<TowerId, TowerSummary>,
+    /// Queue of unreachable towers.
+    pub unreachable_towers: UnboundedSender<(TowerId, RevocationData)>,
+    // Map of existing retriers and its state.
+    pub retriers: HashMap<TowerId, RetrierStatus>,
+    /// The user secret key.
+    pub user_sk: SecretKey,
+    /// The user identifier.
+    pub user_id: UserId,
+    /// Optional proxy
+    pub proxy: Option<ProxyInfo>,
+}
+
+impl WTClient {
+    pub async fn new(
+        data_dir: PathBuf,
+        unreachable_towers: UnboundedSender<(TowerId, RevocationData)>,
+    ) -> Self {
+        Self::with_proxy(data_dir, unreachable_towers, None).await
+    }
+
+    pub async fn with_proxy(
+        data_dir: PathBuf,
+        unreachable_towers: UnboundedSender<(TowerId, RevocationData)>,
+        proxy: Option<ProxyInfo>,
+    ) -> Self {
+        // Create data dir if it does not exist
+        fs::create_dir_all(&data_dir).await.unwrap_or_else(|e| {
+            log::error!("Cannot create data dir: {e:?}");
+            std::process::exit(1);
+        });
+
+        let dbm = DBM::new(&data_dir.join("watchtowers_db.sql3")).unwrap();
+
+        let (user_sk, user_id) = if let Some(sk) = dbm.load_client_key() {
+            (
+                sk,
+                UserId(PublicKey::from_secret_key(&Secp256k1::new(), &sk)),
+            )
+        } else {
+            log::info!("Watchtower client keys not found. Creating a fresh set");
+            let (sk, pk) = cryptography::get_random_keypair();
+            dbm.store_client_key(&sk).unwrap();
+            (sk, UserId(pk))
+        };
+
+        let towers = dbm.load_towers();
+        for (tower_id, tower) in towers.iter() {
+            if tower.status.is_temporary_unreachable() {
+                unreachable_towers
+                    .send((
+                        *tower_id,
+                        RevocationData::Stale(tower.pending_appointments.iter().cloned().collect()),
+                    ))
+                    .unwrap();
+            }
+        }
+
+        log::info!("Plugin watchtower client initialized. User id = {user_id}");
+
+        WTClient {
+            towers,
+            unreachable_towers,
+            retriers: HashMap::new(),
+            dbm,
+            user_sk,
+            user_id,
+            proxy,
+        }
+    }
+
+    /// Adds or updates a tower entry.
+    pub fn add_update_tower(
+        &mut self,
+        tower_id: TowerId,
+        tower_net_addr: &str,
+        receipt: &RegistrationReceipt,
+    ) -> Result<(), SubscriptionError> {
+        if let Some(tower) = self.towers.get(&tower_id) {
+            // TODO: For now we're forcing updates to increase both slots and expiry. This is not mandatory and may
+            // be changed in the future, but the tower is currently set to do this anyway so let's keep it simple.
+            if receipt.subscription_expiry() <= tower.subscription_expiry {
+                return Err(SubscriptionError::Expiry);
+            } else {
+                let tower_info = self.dbm.load_tower_record(tower_id).unwrap();
+                if receipt.available_slots() <= tower_info.available_slots {
+                    return Err(SubscriptionError::Slots);
+                }
+            }
+        }
+
+        self.dbm
+            .store_tower_record(tower_id, tower_net_addr, receipt)
+            .unwrap();
+
+        if let Some(summary) = self.towers.get_mut(&tower_id) {
+            summary.udpate(
+                tower_net_addr.to_owned(),
+                receipt.available_slots(),
+                receipt.subscription_start(),
+                receipt.subscription_expiry(),
+            );
+        } else {
+            self.towers.insert(
+                tower_id,
+                TowerSummary::new(
+                    tower_net_addr.to_owned(),
+                    receipt.available_slots(),
+                    receipt.subscription_start(),
+                    receipt.subscription_expiry(),
+                ),
+            );
+        };
+
+        Ok(())
+    }
+
+    /// Gets the latest registration receipt of a given tower.
+    pub fn get_registration_receipt(&self, tower_id: TowerId) -> Option<RegistrationReceipt> {
+        self.dbm.load_registration_receipt(tower_id, self.user_id)
+    }
+
+    /// Loads a tower record from the database.
+    pub fn load_tower_info(&self, tower_id: TowerId) -> Option<TowerInfo> {
+        self.dbm.load_tower_record(tower_id)
+    }
+
+    /// Gets the given tower status (identified by tower_id), if found.
+    pub fn get_tower_status(&self, tower_id: &TowerId) -> Option<TowerStatus> {
+        Some(self.towers.get(tower_id)?.status)
+    }
+
+    /// Sets the tower status to any of the `TowerStatus` variants.
+    pub fn set_tower_status(&mut self, tower_id: TowerId, status: TowerStatus) {
+        if let Some(tower) = self.towers.get_mut(&tower_id) {
+            if tower.status != status {
+                tower.status = status
+            } else {
+                log::debug!("{tower_id} status is already {status}")
+            }
+        } else {
+            log::error!("Cannot change tower status to {status}. Unknown tower_id: {tower_id}");
+        }
+    }
+
+    /// Gets the given tower status (identified by tower_id), if found.
+    pub fn get_retrier_status(&self, tower_id: &TowerId) -> Option<&RetrierStatus> {
+        self.retriers.get(tower_id)
+    }
+
+    /// Adds an appointment receipt to the tower record.
+    pub fn add_appointment_receipt(
+        &mut self,
+        tower_id: TowerId,
+        locator: Locator,
+        available_slots: u32,
+        receipt: &AppointmentReceipt,
+    ) {
+        if let Some(tower) = self.towers.get_mut(&tower_id) {
+            // DISCUSS: It may be nice to independently compute the slots and compare
+            tower.available_slots = available_slots;
+
+            self.dbm
+                .store_appointment_receipt(tower_id, locator, available_slots, receipt)
+                .unwrap();
+        } else {
+            log::error!("Cannot add appointment receipt to tower. Unknown tower_id: {tower_id}");
+        }
+    }
+
+    /// Gets an appointment receipt from the database (if found).
+    pub fn get_appointment_receipt(
+        &self,
+        tower_id: TowerId,
+        locator: Locator,
+    ) -> Option<AppointmentReceipt> {
+        self.dbm.load_appointment_receipt(tower_id, locator)
+    }
+
+    /// Adds a pending appointment to the tower record.
+    pub fn add_pending_appointment(&mut self, tower_id: TowerId, appointment: &Appointment) {
+        if let Some(tower) = self.towers.get_mut(&tower_id) {
+            tower.pending_appointments.insert(appointment.locator);
+
+            self.dbm
+                .store_pending_appointment(tower_id, appointment)
+                .unwrap();
+        } else {
+            log::error!("Cannot add pending appointment to tower. Unknown tower_id: {tower_id}");
+        }
+    }
+
+    /// Removes a pending appointment from the tower record.
+    pub fn remove_pending_appointment(&mut self, tower_id: TowerId, locator: Locator) {
+        if let Some(tower) = self.towers.get_mut(&tower_id) {
+            tower.pending_appointments.remove(&locator);
+
+            self.dbm
+                .delete_pending_appointment(tower_id, locator)
+                .unwrap();
+        } else {
+            log::error!("Cannot remove pending appointment to tower. Unknown tower_id: {tower_id}");
+        }
+    }
+
+    /// Adds an invalid appointment to the tower record.
+    pub fn add_invalid_appointment(&mut self, tower_id: TowerId, appointment: &Appointment) {
+        if let Some(tower) = self.towers.get_mut(&tower_id) {
+            tower.invalid_appointments.insert(appointment.locator);
+
+            self.dbm
+                .store_invalid_appointment(tower_id, appointment)
+                .unwrap();
+        } else {
+            log::error!("Cannot add invalid appointment to tower. Unknown tower_id: {tower_id}");
+        }
+    }
+
+    /// Flags a given tower as misbehaving, storing the misbehaving proof in the database.
+    pub fn flag_misbehaving_tower(&mut self, tower_id: TowerId, proof: MisbehaviorProof) {
+        if let Some(tower) = self.towers.get_mut(&tower_id) {
+            self.dbm.store_misbehaving_proof(tower_id, &proof).unwrap();
+            tower.status = TowerStatus::Misbehaving;
+        } else {
+            log::error!("Cannot flag tower. Unknown tower_id: {tower_id}");
+        }
+    }
+
+    /// Removes a tower from the client (both memory and database).
+    ///
+    /// Any data associated to the tower will be deleted (i.e. links to appointments)
+    pub fn remove_tower(&mut self, tower_id: TowerId) -> Result<(), DBError> {
+        if self.towers.contains_key(&tower_id) {
+            self.towers.remove(&tower_id);
+            self.dbm.remove_tower_record(tower_id)
+        } else {
+            Err(DBError::NotFound)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use tempdir::TempDir;
+    use tokio::sync::mpsc::unbounded_channel;
+
+    use teos_common::test_utils::{
+        generate_random_appointment, get_random_appointment_receipt,
+        get_random_registration_receipt, get_random_user_id,
+        get_registration_receipt_from_previous,
+    };
+
+    #[tokio::test]
+    async fn test_add_update_load_tower() {
+        let tmp_path = TempDir::new(&format!("watchtower_{}", get_random_user_id())).unwrap();
+        let mut wt_client =
+            WTClient::new(tmp_path.path().to_path_buf(), unbounded_channel().0).await;
+
+        // Adding a new tower will add a summary to towers and the full data to the
+        let mut receipt = get_random_registration_receipt();
+        let (tower_sk, tower_pk) = cryptography::get_random_keypair();
+        let tower_id = TowerId(tower_pk);
+        let tower_info = TowerInfo::empty(
+            "talaia.watch".to_owned(),
+            receipt.available_slots(),
+            receipt.subscription_start(),
+            receipt.subscription_expiry(),
+        );
+
+        wt_client
+            .add_update_tower(tower_id, &tower_info.net_addr, &receipt)
+            .unwrap();
+        assert_eq!(
+            wt_client.towers.get(&tower_id),
+            Some(&TowerSummary::from(tower_info.clone()))
+        );
+        assert_eq!(wt_client.load_tower_info(tower_id).unwrap(), tower_info);
+
+        // Calling the method again with updated information should also updated the records in memory and the database
+        receipt = get_registration_receipt_from_previous(&receipt);
+
+        let updated_tower_info = TowerInfo::empty(
+            "talaia.watch".to_owned(),
+            receipt.available_slots(),
+            receipt.subscription_start(),
+            receipt.subscription_expiry(),
+        );
+        wt_client
+            .add_update_tower(tower_id, &updated_tower_info.net_addr, &receipt)
+            .unwrap();
+
+        assert_eq!(
+            wt_client.towers.get(&tower_id),
+            Some(&TowerSummary::from(updated_tower_info.clone()))
+        );
+        assert_eq!(
+            wt_client.load_tower_info(tower_id).unwrap(),
+            updated_tower_info
+        );
+
+        // If we try to update without increasing both the end_time and the slots, this will fail
+        let mut receipt_same_slots = RegistrationReceipt::new(
+            receipt.user_id(),
+            receipt.available_slots(),
+            receipt.subscription_start(),
+            receipt.subscription_expiry() + 1,
+        );
+        receipt_same_slots.sign(&tower_sk);
+        let mut receipt_same_expiry = RegistrationReceipt::new(
+            receipt.user_id(),
+            receipt.available_slots() + 1,
+            receipt.subscription_start(),
+            receipt.subscription_expiry(),
+        );
+        receipt_same_expiry.sign(&tower_sk);
+
+        assert!(matches!(
+            wt_client.add_update_tower(tower_id, &updated_tower_info.net_addr, &receipt),
+            Err(SubscriptionError::Expiry)
+        ));
+        assert!(matches!(
+            wt_client.add_update_tower(tower_id, &updated_tower_info.net_addr, &receipt_same_slots),
+            Err(SubscriptionError::Slots)
+        ));
+        assert!(matches!(
+            wt_client.add_update_tower(
+                tower_id,
+                &updated_tower_info.net_addr,
+                &receipt_same_expiry
+            ),
+            Err(SubscriptionError::Expiry)
+        ));
+
+        // Decrease the slots count (simulate exhaustion) and update with more than the current count it should work
+        let locator = generate_random_appointment(None).locator;
+        wt_client.add_appointment_receipt(
+            tower_id,
+            locator,
+            0,
+            &get_random_appointment_receipt(tower_sk),
+        );
+        wt_client
+            .add_update_tower(tower_id, &updated_tower_info.net_addr, &receipt_same_slots)
+            .unwrap();
+    }
+
+    #[tokio::test]
+    async fn test_get_tower_status() {
+        let tmp_path = TempDir::new(&format!("watchtower_{}", get_random_user_id())).unwrap();
+        let mut wt_client =
+            WTClient::new(tmp_path.path().to_path_buf(), unbounded_channel().0).await;
+
+        // If the tower is unknown, get_tower_status returns None
+        let tower_id = get_random_user_id();
+        assert!(wt_client.get_tower_status(&tower_id).is_none());
+
+        // Add a tower
+        let receipt = get_random_registration_receipt();
+        wt_client
+            .add_update_tower(tower_id, "talaia.watch", &receipt)
+            .unwrap();
+
+        // If the tower is known, get_tower_status matches getting the same data from the towers collection
+        assert_eq!(
+            wt_client.towers.get(&tower_id).unwrap().status,
+            wt_client.get_tower_status(&tower_id).unwrap()
+        )
+    }
+
+    #[tokio::test]
+    async fn test_set_tower_status() {
+        let tmp_path = TempDir::new(&format!("watchtower_{}", get_random_user_id())).unwrap();
+        let mut wt_client =
+            WTClient::new(tmp_path.path().to_path_buf(), unbounded_channel().0).await;
+
+        // If the tower is unknown nothing will happen
+        let unknown_tower = get_random_user_id();
+        wt_client.set_tower_status(unknown_tower, TowerStatus::Reachable);
+        assert!(!wt_client.towers.contains_key(&unknown_tower));
+
+        // If the tower is known, the status will be updated.
+        let receipt = get_random_registration_receipt();
+        let tower_id = get_random_user_id();
+        wt_client
+            .add_update_tower(tower_id, "talaia.watch", &receipt)
+            .unwrap();
+
+        for status in [
+            TowerStatus::Reachable,
+            TowerStatus::TemporaryUnreachable,
+            TowerStatus::Unreachable,
+            TowerStatus::SubscriptionError,
+            TowerStatus::Misbehaving,
+        ] {
+            wt_client.set_tower_status(tower_id, status);
+            assert_eq!(status, wt_client.get_tower_status(&tower_id).unwrap());
+        }
+    }
+
+    #[tokio::test]
+    async fn test_add_appointment_receipt() {
+        let tmp_path = TempDir::new(&format!("watchtower_{}", get_random_user_id())).unwrap();
+        let mut wt_client =
+            WTClient::new(tmp_path.path().to_path_buf(), unbounded_channel().0).await;
+
+        let (tower_sk, tower_pk) = cryptography::get_random_keypair();
+        let tower_id = TowerId(tower_pk);
+
+        let locator = generate_random_appointment(None).locator;
+        let registration_receipt = get_random_registration_receipt();
+        let appointment_receipt = get_random_appointment_receipt(tower_sk);
+
+        // If we call this on an unknown tower it will simply do nothing
+        wt_client.add_appointment_receipt(
+            tower_id,
+            locator,
+            registration_receipt.available_slots(),
+            &appointment_receipt,
+        );
+        assert!(!wt_client.towers.contains_key(&tower_id));
+
+        // Add the tower to the state and try again
+        let tower_info = TowerInfo::new(
+            "talaia.watch".to_owned(),
+            registration_receipt.available_slots(),
+            registration_receipt.subscription_start(),
+            registration_receipt.subscription_expiry(),
+            HashMap::from([(locator, appointment_receipt.signature().unwrap())]),
+            Vec::new(),
+            Vec::new(),
+        );
+        wt_client
+            .add_update_tower(tower_id, &tower_info.net_addr, &registration_receipt)
+            .unwrap();
+        wt_client.add_appointment_receipt(
+            tower_id,
+            locator,
+            registration_receipt.available_slots(),
+            &appointment_receipt,
+        );
+
+        assert!(wt_client.towers.contains_key(&tower_id));
+        assert_eq!(
+            wt_client.towers.get(&tower_id).unwrap(),
+            &TowerSummary::from(tower_info.clone())
+        );
+        assert_eq!(wt_client.load_tower_info(tower_id).unwrap(), tower_info);
+    }
+
+    #[tokio::test]
+    async fn test_add_pending_appointment() {
+        let tmp_path = TempDir::new(&format!("watchtower_{}", get_random_user_id())).unwrap();
+        let mut wt_client =
+            WTClient::new(tmp_path.path().to_path_buf(), unbounded_channel().0).await;
+
+        let tower_id = get_random_user_id();
+
+        let registration_receipt = get_random_registration_receipt();
+        let appointment = generate_random_appointment(None);
+
+        // If we call this on an unknown tower it will simply do nothing
+        wt_client.add_pending_appointment(tower_id, &appointment);
+        assert!(!wt_client.towers.contains_key(&tower_id));
+
+        // Add the tower to the state and try again
+        let tower_info = TowerInfo::new(
+            "talaia.watch".to_owned(),
+            registration_receipt.available_slots(),
+            registration_receipt.subscription_start(),
+            registration_receipt.subscription_expiry(),
+            HashMap::new(),
+            vec![appointment.clone()],
+            Vec::new(),
+        );
+
+        wt_client
+            .add_update_tower(tower_id, &tower_info.net_addr, &registration_receipt)
+            .unwrap();
+        wt_client.add_pending_appointment(tower_id, &appointment);
+
+        assert!(wt_client.towers.contains_key(&tower_id));
+        assert_eq!(
+            wt_client.towers.get(&tower_id).unwrap(),
+            &TowerSummary::from(tower_info.clone())
+        );
+        // When towers data is loaded from the database, it is assumed to be reachable.
+        assert_eq!(
+            wt_client.load_tower_info(tower_id).unwrap(),
+            tower_info.with_status(TowerStatus::TemporaryUnreachable)
+        );
+    }
+
+    #[tokio::test]
+    async fn test_remove_pending_appointment() {
+        let tmp_path = TempDir::new(&format!("watchtower_{}", get_random_user_id())).unwrap();
+        let mut wt_client =
+            WTClient::new(tmp_path.path().to_path_buf(), unbounded_channel().0).await;
+
+        let tower_id = get_random_user_id();
+
+        let registration_receipt = get_random_registration_receipt();
+        let appointment = generate_random_appointment(None);
+
+        // If we call this on an unknown tower it will simply do nothing
+        wt_client.remove_pending_appointment(tower_id, appointment.locator);
+
+        // Add the tower to the state and try again
+        wt_client
+            .add_update_tower(tower_id, "talaia.watch", &registration_receipt)
+            .unwrap();
+        wt_client.add_pending_appointment(tower_id, &appointment);
+
+        wt_client.remove_pending_appointment(tower_id, appointment.locator);
+        assert!(!wt_client
+            .towers
+            .get(&tower_id)
+            .unwrap()
+            .pending_appointments
+            .contains(&appointment.locator));
+        // This bit is tested exhaustively in the DBM.
+        assert!(!wt_client.dbm.appointment_exists(appointment.locator));
+    }
+
+    #[tokio::test]
+    async fn test_add_invalid_appointment() {
+        let tmp_path = TempDir::new(&format!("watchtower_{}", get_random_user_id())).unwrap();
+        let mut wt_client =
+            WTClient::new(tmp_path.path().to_path_buf(), unbounded_channel().0).await;
+
+        let tower_id = get_random_user_id();
+
+        let registration_receipt = get_random_registration_receipt();
+        let appointment = generate_random_appointment(None);
+
+        // If we call this on an unknown tower it will simply do nothing
+        wt_client.add_invalid_appointment(tower_id, &appointment);
+        assert!(!wt_client.towers.contains_key(&tower_id));
+
+        // Add the tower to the state and try again
+        let tower_info = TowerInfo::new(
+            "talaia.watch".to_owned(),
+            registration_receipt.available_slots(),
+            registration_receipt.subscription_start(),
+            registration_receipt.subscription_expiry(),
+            HashMap::new(),
+            Vec::new(),
+            vec![appointment.clone()],
+        );
+
+        wt_client
+            .add_update_tower(tower_id, &tower_info.net_addr, &registration_receipt)
+            .unwrap();
+        wt_client.add_invalid_appointment(tower_id, &appointment);
+
+        assert!(wt_client.towers.contains_key(&tower_id));
+        assert_eq!(
+            wt_client.towers.get(&tower_id).unwrap(),
+            &TowerSummary::from(tower_info.clone())
+        );
+        assert_eq!(wt_client.load_tower_info(tower_id).unwrap(), tower_info);
+    }
+
+    #[tokio::test]
+    async fn test_move_pending_appointment_to_invalid() {
+        let tmp_path = TempDir::new(&format!("watchtower_{}", get_random_user_id())).unwrap();
+        let mut wt_client =
+            WTClient::new(tmp_path.path().to_path_buf(), unbounded_channel().0).await;
+
+        let tower_id = get_random_user_id();
+
+        let registration_receipt = get_random_registration_receipt();
+        let appointment = generate_random_appointment(None);
+
+        wt_client
+            .add_update_tower(tower_id, "talaia.watch", &registration_receipt)
+            .unwrap();
+        wt_client.add_pending_appointment(tower_id, &appointment);
+
+        // Check that the appointment can be moved from pending to invalid
+        wt_client.add_invalid_appointment(tower_id, &appointment);
+        wt_client.remove_pending_appointment(tower_id, appointment.locator);
+
+        assert!(!wt_client
+            .towers
+            .get(&tower_id)
+            .unwrap()
+            .pending_appointments
+            .contains(&appointment.locator));
+        assert!(wt_client
+            .towers
+            .get(&tower_id)
+            .unwrap()
+            .invalid_appointments
+            .contains(&appointment.locator));
+        assert!(!wt_client
+            .dbm
+            .load_appointment_locators(tower_id, crate::AppointmentStatus::Pending)
+            .contains(&appointment.locator));
+        assert!(wt_client
+            .dbm
+            .load_appointment_locators(tower_id, crate::AppointmentStatus::Invalid)
+            .contains(&appointment.locator));
+        assert!(wt_client.dbm.appointment_exists(appointment.locator));
+    }
+
+    #[tokio::test]
+    async fn test_move_pending_appointment_to_invalid_multiple_towers() {
+        // Check that moving an appointment from pending to invalid can be done even if multiple towers have a reference to it
+        let tmp_path = TempDir::new(&format!("watchtower_{}", get_random_user_id())).unwrap();
+        let mut wt_client =
+            WTClient::new(tmp_path.path().to_path_buf(), unbounded_channel().0).await;
+
+        let tower_id = get_random_user_id();
+        let another_tower_id = get_random_user_id();
+        let tower_net_addr = "talaia.watch";
+
+        let registration_receipt = get_random_registration_receipt();
+        let appointment = generate_random_appointment(None);
+
+        wt_client
+            .add_update_tower(tower_id, tower_net_addr, &registration_receipt)
+            .unwrap();
+        wt_client
+            .add_update_tower(another_tower_id, tower_net_addr, &registration_receipt)
+            .unwrap();
+        wt_client.add_pending_appointment(tower_id, &appointment);
+        wt_client.add_pending_appointment(another_tower_id, &appointment);
+
+        // Check that the appointment can be moved from pending to invalid
+        wt_client.add_invalid_appointment(tower_id, &appointment);
+        wt_client.remove_pending_appointment(tower_id, appointment.locator);
+
+        // TOWER_ID CHECKS
+        assert!(!wt_client
+            .towers
+            .get(&tower_id)
+            .unwrap()
+            .pending_appointments
+            .contains(&appointment.locator));
+        assert!(wt_client
+            .towers
+            .get(&tower_id)
+            .unwrap()
+            .invalid_appointments
+            .contains(&appointment.locator));
+        assert!(!wt_client
+            .dbm
+            .load_appointment_locators(tower_id, crate::AppointmentStatus::Pending)
+            .contains(&appointment.locator));
+        assert!(wt_client
+            .dbm
+            .load_appointment_locators(tower_id, crate::AppointmentStatus::Invalid)
+            .contains(&appointment.locator));
+
+        // ANOTHER_TOWER_ID CHECKS
+        assert!(wt_client
+            .towers
+            .get(&another_tower_id)
+            .unwrap()
+            .pending_appointments
+            .contains(&appointment.locator));
+        assert!(!wt_client
+            .towers
+            .get(&another_tower_id)
+            .unwrap()
+            .invalid_appointments
+            .contains(&appointment.locator));
+        assert!(wt_client
+            .dbm
+            .load_appointment_locators(another_tower_id, crate::AppointmentStatus::Pending)
+            .contains(&appointment.locator));
+        assert!(!wt_client
+            .dbm
+            .load_appointment_locators(another_tower_id, crate::AppointmentStatus::Invalid)
+            .contains(&appointment.locator));
+
+        // GENERAL
+        assert!(wt_client.dbm.appointment_exists(appointment.locator));
+    }
+
+    #[tokio::test]
+    async fn test_flag_misbehaving_tower() {
+        let tmp_path = TempDir::new(&format!("watchtower_{}", get_random_user_id())).unwrap();
+        let mut wt_client =
+            WTClient::new(tmp_path.path().to_path_buf(), unbounded_channel().0).await;
+
+        let (tower_sk, tower_pk) = cryptography::get_random_keypair();
+        let tower_id = TowerId(tower_pk);
+
+        // If we call this on an unknown tower it will simply do nothing
+        let appointment = generate_random_appointment(None);
+        let receipt = get_random_appointment_receipt(tower_sk);
+        let proof = MisbehaviorProof::new(appointment.locator, receipt, get_random_user_id());
+        wt_client.flag_misbehaving_tower(tower_id, proof.clone());
+        assert!(!wt_client.towers.contains_key(&tower_id));
+
+        // // Add the tower to the state and try again
+        let registration_receipt = get_random_registration_receipt();
+        wt_client
+            .add_update_tower(tower_id, "talaia.watch", &registration_receipt)
+            .unwrap();
+        wt_client.flag_misbehaving_tower(tower_id, proof.clone());
+
+        // Check data in memory
+        let tower_summary = wt_client.towers.get(&tower_id);
+        assert!(tower_summary.is_some());
+        assert!(tower_summary.unwrap().status.is_misbehaving());
+
+        // Check data in DB
+        let loaded_info = wt_client.load_tower_info(tower_id).unwrap();
+        assert!(loaded_info.status.is_misbehaving());
+        assert_eq!(loaded_info.misbehaving_proof, Some(proof));
+        assert!(loaded_info.appointments.contains_key(&appointment.locator));
+    }
+
+    #[tokio::test]
+    async fn test_remove_tower() {
+        let tmp_path = TempDir::new(&format!("watchtower_{}", get_random_user_id())).unwrap();
+        let mut wt_client =
+            WTClient::new(tmp_path.path().to_path_buf(), unbounded_channel().0).await;
+
+        let receipt = get_random_registration_receipt();
+        let (tower_sk, tower_pk) = cryptography::get_random_keypair();
+        let tower_id = TowerId(tower_pk);
+        let tower_info = TowerInfo::empty(
+            "talaia.watch".to_owned(),
+            receipt.available_slots(),
+            receipt.subscription_start(),
+            receipt.subscription_expiry(),
+        );
+
+        // Add the tower and check it is there
+        wt_client
+            .add_update_tower(tower_id, &tower_info.net_addr, &receipt)
+            .unwrap();
+        assert_eq!(
+            wt_client.towers.get(&tower_id),
+            Some(&TowerSummary::from(tower_info.clone()))
+        );
+        assert_eq!(wt_client.load_tower_info(tower_id).unwrap(), tower_info);
+
+        // Remove the tower and check it is not there anymore
+        wt_client.remove_tower(tower_id).unwrap();
+        assert!(wt_client.load_tower_info(tower_id).is_none());
+        assert!(!wt_client.towers.contains_key(&tower_id));
+
+        // Try again but this time with an associated appointment to check that it also gets removed
+        wt_client
+            .add_update_tower(tower_id, &tower_info.net_addr, &receipt)
+            .unwrap();
+
+        let locator = generate_random_appointment(None).locator;
+        let registration_receipt = get_random_registration_receipt();
+        let appointment_receipt = get_random_appointment_receipt(tower_sk);
+
+        // If we call this on an unknown tower it will simply do nothing
+        wt_client.add_appointment_receipt(
+            tower_id,
+            locator,
+            registration_receipt.available_slots(),
+            &appointment_receipt,
+        );
+        assert!(wt_client.dbm.appointment_receipt_exists(locator, tower_id));
+
+        // Remove and check both the tower and the appointment
+        wt_client.remove_tower(tower_id).unwrap();
+        assert!(wt_client.load_tower_info(tower_id).is_none());
+        assert!(!wt_client.towers.contains_key(&tower_id));
+        assert!(!wt_client.dbm.appointment_receipt_exists(locator, tower_id));
+    }
+
+    #[tokio::test]
+    async fn test_remove_tower_shared_appointment() {
+        // Lets test removing a tower that has associated data shared with another tower.
+        // For instance, having an appointment that was sent to two towers, and then deleting one of them
+        // should only remove the link between the tower and the appointment, but not delete the data.
+        let tmp_path = TempDir::new(&format!("watchtower_{}", get_random_user_id())).unwrap();
+        let mut wt_client =
+            WTClient::new(tmp_path.path().to_path_buf(), unbounded_channel().0).await;
+
+        let receipt = get_random_registration_receipt();
+        let (tower1_sk, tower1_pk) = cryptography::get_random_keypair();
+        let tower1_id = TowerId(tower1_pk);
+        let (tower2_sk, tower2_pk) = cryptography::get_random_keypair();
+        let tower2_id = TowerId(tower2_pk);
+
+        wt_client
+            .add_update_tower(tower1_id, "talaia.watch", &receipt)
+            .unwrap();
+        wt_client
+            .add_update_tower(tower2_id, "talaia.watch", &receipt)
+            .unwrap();
+
+        let locator = generate_random_appointment(None).locator;
+        let registration_receipt = get_random_registration_receipt();
+        let appointment_receipt_1 = get_random_appointment_receipt(tower1_sk);
+        let appointment_receipt_2 = get_random_appointment_receipt(tower2_sk);
+
+        wt_client.add_appointment_receipt(
+            tower1_id,
+            locator,
+            registration_receipt.available_slots(),
+            &appointment_receipt_1,
+        );
+        wt_client.add_appointment_receipt(
+            tower2_id,
+            locator,
+            registration_receipt.available_slots(),
+            &appointment_receipt_2,
+        );
+
+        // Check that the data exists in both towers
+        assert!(wt_client.dbm.appointment_receipt_exists(locator, tower1_id));
+        assert!(wt_client.dbm.appointment_receipt_exists(locator, tower2_id));
+
+        // Remove tower1 and check that the appointment receipt can still be found for tower2
+        wt_client.remove_tower(tower1_id).unwrap();
+        assert!(wt_client.load_tower_info(tower1_id).is_none());
+
+        assert!(!wt_client.dbm.appointment_receipt_exists(locator, tower1_id));
+        assert!(wt_client.dbm.appointment_receipt_exists(locator, tower2_id));
+    }
+
+    #[tokio::test]
+    async fn test_remove_inexistent_tower() {
+        let tmp_path = TempDir::new(&format!("watchtower_{}", get_random_user_id())).unwrap();
+        let mut wt_client =
+            WTClient::new(tmp_path.path().to_path_buf(), unbounded_channel().0).await;
+
+        assert!(matches!(
+            wt_client.remove_tower(get_random_user_id()),
+            Err(DBError::NotFound)
+        ));
+    }
+}

watchtower-plugin/tests/conftest.py

@@ -0,0 +1,122 @@
+from pathlib import Path
+import subprocess
+
+from pyln.testing.fixtures import *  # noqa: F401,F403
+from pyln.testing.utils import BITCOIND_CONFIG, TailableProc
+
+WT_PLUGIN = Path("~/.cargo/bin/watchtower-client").expanduser()
+TEOSD_CONFIG = {
+    "btc_network": "regtest",
+    "polling_delta": 0,
+}
+
+
+def write_toml_config(filename, opts):
+    with open(filename, "w") as f:
+        for k, v in opts.items():
+            if isinstance(v, str):
+                f.write('{} = "{}"\n'.format(k, v))
+            else:
+                f.write("{} = {}\n".format(k, v))
+
+
+class TeosCLI:
+    def __init__(self, directory="/tmp/watchtower-test"):
+        self.datadir = directory
+
+    def _call(self, method_name, *args):
+        try:
+            r = subprocess.run(
+                ["teos-cli", f"--datadir={self.datadir}/teos", method_name, *args],
+                capture_output=True,
+                text=True,
+            )
+            if r.returncode != 0:
+                result = ValueError(f"Unknown method {method_name}")
+            else:
+                result = json.loads(r.stdout)
+        except json.JSONDecodeError:
+            result = None
+        return result
+
+    def __getattr__(self, name):
+        if name.startswith("__") and name.endswith("__"):
+            # Prevent RPC calls for non-existing python internal attribute
+            # access. If someone tries to get an internal attribute
+            # of RawProxy instance, and the instance does not have this
+            # attribute, we do not want the bogus RPC call to happen.
+            raise AttributeError
+
+        # Create a callable to do the actual call
+        f = lambda *args: self._call(name, *args)  # noqa: E731
+
+        # Make debuggers show <function teos.cli.name> rather than <function
+        # teos.cli.<lambda>>
+        f.__name__ = name
+        return f
+
+
+class TeosD(TailableProc):
+    def __init__(self, bitcoind_rpcport, directory="/tmp/watchtower-test"):
+        self.teos_dir = os.path.join(directory, "teos")
+        self.prefix = "teosd"
+        TailableProc.__init__(self, self.teos_dir)
+        self.cli = TeosCLI(directory)
+
+        if not os.path.exists(self.teos_dir):
+            os.makedirs(self.teos_dir)
+
+        self.cmd_line = [
+            "teosd",
+            f"--datadir={self.teos_dir}",
+            f'--btcrpcuser={BITCOIND_CONFIG["rpcuser"]}',
+            f'--btcrpcpassword={BITCOIND_CONFIG["rpcpassword"]}',
+            f"--btcrpcport={bitcoind_rpcport}",
+        ]
+
+        self.conf_file = os.path.join(self.teos_dir, "teos.toml")
+        write_toml_config(self.conf_file, TEOSD_CONFIG)
+
+    def start(self, overwrite_key=False):
+        if overwrite_key:
+            self.cmd_line.append("--overwritekey")
+        TailableProc.start(self)
+        self.wait_for_log("Tower ready")
+
+        logging.info("TeosD started")
+
+    def stop(self):
+        self.cli.stop()
+        self.wait_for_log("Shutting down tower")
+
+        return TailableProc.stop(self)
+
+
+@pytest.fixture
+def teosd(bitcoind, directory):
+    # Set the user data dir for the watchtower-plugin so it uses a unique one per test.
+    os.environ["TOWERS_DATA_DIR"] = os.path.join(directory, "watchtower")
+
+    teosd = TeosD(directory=directory, bitcoind_rpcport=bitcoind.rpcport)
+    teosd.start()
+    yield teosd
+
+    teosd.stop()
+
+
+@pytest.hookimpl(tryfirst=True, hookwrapper=True)
+def pytest_runtest_makereport(item, call):
+    # execute all other hooks to obtain the report object
+    outcome = yield
+    rep = outcome.get_result()
+
+    # set a report attribute for each phase of a call, which can
+    # be "setup", "call", "teardown"
+
+    setattr(item, "rep_" + rep.when, rep)
+
+
+@pytest.fixture(scope="function", autouse=True)
+def log_name(request):
+    # Here logging is used, you can use whatever you want to use for logs
+    logging.info("Starting '{}'".format(request.node.name))

watchtower-plugin/tests/pyproject.toml

@@ -0,0 +1,21 @@
+[tool.poetry]
+name = "tests"
+version = "0.1.2"
+description = "watchtower-plugin tests"
+authors = ["Sergi Delgado Segura <sergi.delgado.s@gmail.com>"]
+license = "MIT"
+
+[tool.poetry.dependencies]
+python = "^3.9"
+black = "^22.6.0"
+
+[tool.poetry.dev-dependencies]
+pytest = "^7.1.2"
+pytest-timeout = "^2.1.0"
+pyln-testing = "^24.2.1"
+pyln-client = "^24.2.1"
+
+
+[build-system]
+requires = ["poetry-core>=1.0.0"]
+build-backend = "poetry.core.masonry.api"

watchtower-plugin/tests/test.py

@@ -0,0 +1,243 @@
+import pytest
+from conftest import WT_PLUGIN
+
+
+def change_endianness(x):
+    """Changes the endianness (from BE to LE and vice versa) of a given value.
+
+    :param x: Given value which endianness will be changed.
+    :type x: hex str
+    :return: The opposite endianness representation of the given value.
+    :rtype: hex str
+    """
+
+    b = bytes.fromhex(x)
+    return b[::-1].hex()
+
+
+def test_watchtower(node_factory, bitcoind, teosd):
+    """
+    Test watchtower hook.
+
+    l1 and l2 open a channel, make a couple of updates and then l1 cheats on
+    l2 while that one is offline. The watchtower plugin meanwhile stashes all
+    the penalty transactions and we release the one matching the offending
+    commitment transaction.
+    """
+
+    l1, l2 = node_factory.line_graph(
+        2,
+        opts=[
+            {"broken_log": r"Could not find resolution for output [0-9]?: did \*we\* cheat\?"},
+            {"plugin": WT_PLUGIN},
+        ],
+    )
+
+    # We need to register l2 with the tower
+    tower_id = teosd.cli.gettowerinfo()["tower_id"]
+    l2.rpc.registertower(tower_id)
+
+    # Force a new commitment
+    l1.rpc.pay(l2.rpc.invoice(25000000, "lbl1", "desc1")["bolt11"])
+    tx = l1.rpc.dev_sign_last_tx(l2.info["id"])["tx"]
+
+    # Now make sure it is out of date
+    l1.rpc.pay(l2.rpc.invoice(25000000, "lbl2", "desc2")["bolt11"])
+
+    # l2 stops watching the chain, allowing the watchtower to react
+    l2.stop()
+
+    # Now l1 cheats
+    dispute_txid = bitcoind.rpc.sendrawtransaction(tx)
+    locator = change_endianness(dispute_txid[32:])
+
+    # Make sure l2's normal penalty_tx doesn't reach the network
+    l2.daemon.rpcproxy.mock_rpc("sendrawtransaction", lambda _: {"result": None, "error": None, "id": "pytest"})
+    l2.start()
+
+    # The tower will react once the dispute gets confirmed. For now it is still watching for it
+    assert l2.rpc.getappointment(tower_id, locator)["status"] == "being_watched"
+
+    # Confirm the dispute so the tower can react with the penalty
+    bitcoind.generate_block()
+    l1.daemon.wait_for_log("State changed from FUNDING_SPEND_SEEN to ONCHAIN")
+    penalty_txid = bitcoind.rpc.getrawmempool()[0]
+
+    # The channel still exists between the two peers, but it's on chain
+    assert l1.rpc.listpeerchannels()["channels"][0]["state"] == "ONCHAIN"
+    assert l2.rpc.getappointment(tower_id, locator)["status"] == "dispute_responded"
+
+    # Generate blocks until the penalty gets irrevocably resolved
+    for i in range(101):
+        bitcoind.generate_block()
+        if i < 100:
+            assert l2.rpc.getappointment(tower_id, locator)["status"] == "dispute_responded"
+        else:
+            # Once the channel gets irrevocably resolved the tower will forget about it
+            assert l2.rpc.getappointment(tower_id, locator) == {
+                "error": "Appointment not found",
+                "error_code": 36,
+            }
+
+    # Make sure the penalty outputs are in l2's wallet
+    fund_txids = [o["txid"] for o in l2.rpc.listfunds()["outputs"]]
+    assert penalty_txid in fund_txids
+
+
+@pytest.mark.timeout(60)
+def test_unreachable_watchtower(node_factory, bitcoind, teosd):
+    # Set the max retry interval to 1 sec so we know how much to wait for the next retry attempt
+    max_interval_time = 1
+    l1, l2 = node_factory.line_graph(
+        2,
+        opts=[
+            {},
+            {
+                "plugin": WT_PLUGIN,
+                "dev-watchtower-max-retry-interval": max_interval_time,
+            },
+        ],
+    )
+
+    # We need to register l2 with the tower
+    tower_id = teosd.cli.gettowerinfo()["tower_id"]
+    l2.rpc.registertower(tower_id)
+
+    # Stop the tower
+    teosd.stop()
+
+    # Make a new payment with an unreachable tower
+    l1.rpc.pay(l2.rpc.invoice(25000000, "lbl1", "desc1")["bolt11"])
+    assert l2.rpc.gettowerinfo(tower_id)["status"] == "temporary_unreachable"
+    assert l2.rpc.gettowerinfo(tower_id)["pending_appointments"]
+
+    # Start the tower and check the automatic backoff works
+    teosd.start()
+    l2.daemon.wait_for_log(f"Retry strategy succeeded for {tower_id}")
+
+    assert l2.rpc.gettowerinfo(tower_id)["status"] == "reachable"
+
+
+def test_auto_retry_watchtower(node_factory, bitcoind, teosd):
+    # The plugin is set to give up on retrying straight-away so we can test this fast.
+    l1, l2 = node_factory.line_graph(
+        2,
+        opts=[
+            {},
+            {
+                "plugin": WT_PLUGIN,
+                "broken_log": r"plugin-watchtower-client: Data was send to an idle retrier. This should have never happened. Please report!.*",
+                "watchtower-max-retry-time": 1,
+                "watchtower-auto-retry-delay": 1,
+            },
+        ],
+    )
+
+    # We need to register l2 with the tower
+    tower_id = teosd.cli.gettowerinfo()["tower_id"]
+    l2.rpc.registertower(tower_id)
+
+    # Stop the tower
+    teosd.stop()
+
+    # Make a new payment with an unreachable tower
+    l1.rpc.pay(l2.rpc.invoice(25000000, "lbl1", "desc1")["bolt11"])
+
+    # Wait until the tower has been flagged as unreachable
+    l2.daemon.wait_for_log("Starting to idle")
+    assert l2.rpc.gettowerinfo(tower_id)["status"] == "unreachable"
+    assert l2.rpc.gettowerinfo(tower_id)["pending_appointments"]
+
+    # Start the tower and retry it
+    teosd.start()
+
+    l2.daemon.wait_for_log(f"Finished idling. Flagging {tower_id} for retry")
+    l2.daemon.wait_for_log(f"Retry strategy succeeded for {tower_id}")
+    assert l2.rpc.gettowerinfo(tower_id)["status"] == "reachable"
+
+
+def test_manually_retry_watchtower(node_factory, bitcoind, teosd):
+    # The plugin is set to give up on retrying straight-away so we can test this fast.
+    l1, l2 = node_factory.line_graph(
+        2,
+        opts=[
+            {},
+            {
+                "plugin": WT_PLUGIN,
+                "watchtower-max-retry-time": 0,
+            },
+        ],
+    )
+
+    # We need to register l2 with the tower
+    tower_id = teosd.cli.gettowerinfo()["tower_id"]
+    l2.rpc.registertower(tower_id)
+
+    # Stop the tower
+    teosd.stop()
+
+    # Make a new payment with an unreachable tower
+    l1.rpc.pay(l2.rpc.invoice(25000000, "lbl1", "desc1")["bolt11"])
+
+    # Wait until the tower has been flagged as unreachable
+    l2.daemon.wait_for_log("Starting to idle")
+    assert l2.rpc.gettowerinfo(tower_id)["status"] == "unreachable"
+    assert l2.rpc.gettowerinfo(tower_id)["pending_appointments"]
+
+    # Start the tower and retry it
+    teosd.start()
+
+    # Manual retry
+    l2.rpc.retrytower(tower_id)
+    l2.daemon.wait_for_log(f"Manually finished idling. Flagging {tower_id} for retry")
+    l2.daemon.wait_for_log(f"Retry strategy succeeded for {tower_id}")
+    assert l2.rpc.gettowerinfo(tower_id)["status"] == "reachable"
+
+
+def test_misbehaving_watchtower(node_factory, bitcoind, teosd, directory):
+    l1, l2 = node_factory.line_graph(2, opts=[{}, {"plugin": WT_PLUGIN}])
+
+    # We need to register l2 with the tower
+    tower_id = teosd.cli.gettowerinfo()["tower_id"]
+    l2.rpc.registertower(tower_id)
+
+    # Restart overwriting the tower private key
+    teosd.stop()
+    teosd.start(overwrite_key=True)
+
+    # Make a new payment and check the state
+    l1.rpc.pay(l2.rpc.invoice(25000000, "lbl1", "desc1")["bolt11"])
+    assert l2.rpc.gettowerinfo(tower_id)["status"] == "misbehaving"
+    assert l2.rpc.gettowerinfo(tower_id)["misbehaving_proof"]
+
+
+def test_get_appointment(node_factory, bitcoind, teosd, directory):
+    l1, l2 = node_factory.line_graph(2, opts=[{}, {"plugin": WT_PLUGIN}])
+
+    # We need to register l2 with the tower
+    tower_id = teosd.cli.gettowerinfo()["tower_id"]
+    l2.rpc.registertower(tower_id)
+
+    # Force a new commitment
+    l1.rpc.pay(l2.rpc.invoice(25000000, "lbl1", "desc1")["bolt11"])
+    tx = l1.rpc.dev_sign_last_tx(l2.info["id"])["tx"]
+
+    # Now make sure it is out of date
+    l1.rpc.pay(l2.rpc.invoice(25000000, "lbl2", "desc2")["bolt11"])
+
+    # Now l1 cheats
+    dispute_txid = bitcoind.rpc.sendrawtransaction(tx)
+    locator = change_endianness(dispute_txid[32:])
+
+    # Check the appointment before mining a block
+    appointment = l2.rpc.getappointment(tower_id, locator)["appointment"]
+    assert "locator" in appointment and "encrypted_blob" in appointment and "to_self_delay" in appointment
+
+    # And after. Now this should be a tracker
+    bitcoind.generate_block()
+    teosd.wait_for_log("New tracker added")
+    tracker = l2.rpc.getappointment(tower_id, locator)["appointment"]
+    assert "dispute_txid" in tracker and "penalty_txid" in tracker and "penalty_rawtx" in tracker
+
+    # Manually stop l2, otherwise the tower may be stopped before the tower client and we may get some BROKEN logs.
+    l2.stop()