6544ea5035 refactor: Block unsafe fs::path std::string conversion calls (Russell Yanofsky)
b39a477ec6 refactor: Add fs::PathToString, fs::PathFromString, u8string, u8path functions (Russell Yanofsky)
Pull request description:
The `fs::path` class has a `std::string` constructor which will implicitly convert from strings. Implicit conversions like this are not great in general because they can hide complexity and inefficiencies in the code, but this case is especially bad, because after the transition from `boost::filesystem` to `std::filesystem` in #20744 the behavior of this constructor on windows will be more complicated and can mangle path strings. The `fs::path` class also has a `.string()` method which is inverse of the constructor and has the same problems.
Fix this by replacing the unsafe method calls with `PathToString` and `PathFromString` function calls, and by forbidding unsafe method calls in the future.
ACKs for top commit:
kiminuo:
ACK 6544ea5035
laanwj:
Code review ACK 6544ea5035
hebasto:
re-ACK 6544ea5035, only added `fsbridge_stem` test case, updated comment, and rebased since my [previous](https://github.com/bitcoin/bitcoin/pull/22937#pullrequestreview-765503126) review. Verified with the following command:
Tree-SHA512: c36324740eb4ee55151146626166c00d5ccc4b6f3df777e75c112bcb4d1db436c1d9cc8c29a1e7fb96051457d317961ab42e6c380c3be2771d135771b2b49fa0
fa43e7c2d9 bitcoin-tx: Avoid treating overflow as OP_0 (MarcoFalke)
fa053c0019 style: Fix whitespace in Parse* functions (MarcoFalke)
fa03dec7e9 refactor: Use C++11 range based for loop in ParseScript (MarcoFalke)
fad55e79ca doc: Fixup ToIntegral docs (MarcoFalke)
Pull request description:
Seems odd to treat integer overflow as `OP_0`, so fix that.
ACKs for top commit:
theStack:
re-ACK fa43e7c2d9
shaavan:
ACK fa43e7c2d9
Tree-SHA512: 1bbe2de62d853badc18d57d169c6e78ddcdff037e5a85357995dead11c8e67a4fe35087e08a181c60753f8ce91058b7fcc06f5b7901afedc78fbacea8bc3ef4f
ac402e749c util: Conditionalize some syscalls in syscall name table (W. J. van der Laan)
64085b37f8 util: Add __NR_copy_file_range syscall constant for sandbox (W. J. van der Laan)
Pull request description:
Make the new syscall sandbox compilable with kernel 4.4.0.
This defines a further syscall constant `__NR_copy_file_range` to make sure all syscalls used in the profile are available even if not defined in the kernel headers.
Also, make a few syscalls optional in the syscall name table:
- `__NR_pkey_alloc`
- `__NR_pkey_free`
- `__NR_pkey_mprotect`
- `__NR_preadv2`
- `__NR_pwritev2`
ACKs for top commit:
practicalswift:
cr ACK ac402e749c
Tree-SHA512: be6c55bf0a686bcdfad0b80b950d0d7d77a559ac234fc997b47514bdba44865a371c96dd8d34a811ba46424a84f410e23f75485b9b1e69e529b7d40e0b4b91b8
Put these in `#ifdef` as they are newer syscalls that might not be
defined on all kernels:
__NR_pkey_alloc
__NR_pkey_free
__NR_pkey_mprotect
__NR_preadv2
__NR_pwritev2
Thanks to jamesob for reporting.
There is no change in behavior. This just helps prepare for the
transition from boost::filesystem to std::filesystem by avoiding calls
to methods which will be unsafe after the transaction to std::filesystem
to due lack of a boost::filesystem::path::imbue equivalent and inability
to set a predictable locale.
Co-authored-by: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
Co-authored-by: Kiminuo <kiminuo@protonmail.com>
Co-authored-by: MarcoFalke <falke.marco@gmail.com>
2d0279987e util: Make sure syscall numbers used in profile are defined (W. J. van der Laan)
8289d19ea5 util: Define SECCOMP_RET_KILL_PROCESS if not provided by the headers (W. J. van der Laan)
Pull request description:
Looks like we've broke the GUIX build in #20487. This attempts to fix it:
- Define `__NR_statx` `__NR_getrandom` `__NR_membarrier` as some kernel headers lack them, and it's important to have the same profile independent on what kernel is used for building.
- Define `SECCOMP_RET_KILL_PROCESS` as it isn't defined in the headers.
ACKs for top commit:
practicalswift:
cr ACK 2d0279987e
Tree-SHA512: c264c66f90af76bf364150e44d0a31876c2ef99f05777fcdd098a23f1e80efef43028f54bf9b3dad016110056d303320ed9741b0cb4c6266175fa9d5589b4277
Define the following syscall numbers for x86_64, so that the profile
will be the same no matter what kernel is built against, including
kernels that don't have `__NR_statx`:
```c++
#define __NR_statx 332
#define __NR_getrandom 318
#define __NR_membarrier 324
```
44d77d2213 sandbox: add copy_file_range to allowed filesystem syscalls (fanquake)
ee08741c9c sandbox: add newfstatat to allowed filesystem syscalls (fanquake)
Pull request description:
Similar to #23178, this is a follow up to #20487, which has broken running the unit tests for some developers. Fix this by adding `newfstatat` to the list of allowed filesystem related calls.
ACKs for top commit:
achow101:
ACK 44d77d2213
laanwj:
Code review ACK 44d77d2213
practicalswift:
cr ACK 44d77d2213
Tree-SHA512: ce9d1b441ebf25bd2cf290566e05864223c1418dab315c962e1094ad877db5dd9fcab94ab98a46da8b712a8f5f46675d62ca3349215d8df46ec5b3c4d72dbaa6
9d0379cea6 consensus: use <cstdint> over <stdint.h> in amount.h (fanquake)
863e52fe63 consensus: make COIN & MAX_MONEY constexpr (fanquake)
d09071da5b [MOVEONLY] consensus: move amount.h into consensus (fanquake)
Pull request description:
A first step (of a few) towards some source code reorganization, as well as making libbitcoinconsensus slightly more self contained.
Related to #15732.
ACKs for top commit:
MarcoFalke:
concept ACK 9d0379cea6 🏝
Tree-SHA512: 97fc79262dcb8c00996852a288fee69ddf8398ae2c95700bba5b326f1f38ffcfaf8fa66e29d0cb446d9b3f4e608a96525fae0c2ad9cd531ad98ad2a4a687cd6a
4747da3a5b Add syscall sandboxing (seccomp-bpf) (practicalswift)
Pull request description:
Add experimental syscall sandboxing using seccomp-bpf (Linux secure computing mode).
Enable filtering of system calls using seccomp-bpf: allow only explicitly allowlisted (expected) syscalls to be called.
The syscall sandboxing implemented in this PR is an experimental feature currently available only under Linux x86-64.
To enable the experimental syscall sandbox the `-sandbox=<mode>` option must be passed to `bitcoind`:
```
-sandbox=<mode>
Use the experimental syscall sandbox in the specified mode
(-sandbox=log-and-abort or -sandbox=abort). Allow only expected
syscalls to be used by bitcoind. Note that this is an
experimental new feature that may cause bitcoind to exit or crash
unexpectedly: use with caution. In the "log-and-abort" mode the
invocation of an unexpected syscall results in a debug handler
being invoked which will log the incident and terminate the
program (without executing the unexpected syscall). In the
"abort" mode the invocation of an unexpected syscall results in
the entire process being killed immediately by the kernel without
executing the unexpected syscall.
```
The allowed syscalls are defined on a per thread basis.
I've used this feature since summer 2020 and I find it to be a helpful testing/debugging addition which makes it much easier to reason about the actual capabilities required of each type of thread in Bitcoin Core.
---
Quick start guide:
```
$ ./configure
$ src/bitcoind -regtest -debug=util -sandbox=log-and-abort
…
2021-06-09T12:34:56Z Experimental syscall sandbox enabled (-sandbox=log-and-abort): bitcoind will terminate if an unexpected (not allowlisted) syscall is invoked.
…
2021-06-09T12:34:56Z Syscall filter installed for thread "addcon"
2021-06-09T12:34:56Z Syscall filter installed for thread "dnsseed"
2021-06-09T12:34:56Z Syscall filter installed for thread "net"
2021-06-09T12:34:56Z Syscall filter installed for thread "msghand"
2021-06-09T12:34:56Z Syscall filter installed for thread "opencon"
2021-06-09T12:34:56Z Syscall filter installed for thread "init"
…
# A simulated execve call to show the sandbox in action:
2021-06-09T12:34:56Z ERROR: The syscall "execve" (syscall number 59) is not allowed by the syscall sandbox in thread "msghand". Please report.
…
Aborted (core dumped)
$
```
---
[About seccomp and seccomp-bpf](https://en.wikipedia.org/wiki/Seccomp):
> In computer security, seccomp (short for secure computing mode) is a facility in the Linux kernel. seccomp allows a process to make a one-way transition into a "secure" state where it cannot make any system calls except exit(), sigreturn(), and read() and write() to already-open file descriptors. Should it attempt any other system calls, the kernel will terminate the process with SIGKILL or SIGSYS. In this sense, it does not virtualize the system's resources but isolates the process from them entirely.
>
> […]
>
> seccomp-bpf is an extension to seccomp that allows filtering of system calls using a configurable policy implemented using Berkeley Packet Filter rules. It is used by OpenSSH and vsftpd as well as the Google Chrome/Chromium web browsers on Chrome OS and Linux. (In this regard seccomp-bpf achieves similar functionality, but with more flexibility and higher performance, to the older systrace—which seems to be no longer supported for Linux.)
ACKs for top commit:
laanwj:
Code review and lightly tested ACK 4747da3a5b
Tree-SHA512: e1c28e323eb4409a46157b7cc0fc29a057ba58d1ee2de268962e2ade28ebd4421b5c2536c64a3af6e9bd3f54016600fec88d016adb49864b63edea51ad838e17
Conflicts were mostly obvious, except for those in CreateTransactionInternal.
(This function was moved from wallet.cpp to spend.cpp, and substantially
rewritten, between 0.21 and 22.0.) For those I manually applied the changes
from the diff, which wound up taking a slightly different form.
Also had to update the new test because the `addresses` field of the RPC
output was removed.
fa9d72a794 Remove unused ParseDouble and ParsePrechecks (MarcoFalke)
fa3cd28535 refactor: Remove unused ParsePrechecks from ParseIntegral (MarcoFalke)
Pull request description:
All of the `ParsePrechecks` are already done by `ToIntegral`, so remove them from `ParseIntegral`.
Also:
* Remove redundant `{}`. See https://github.com/bitcoin/bitcoin/pull/20457#discussion_r720116866
* Add missing failing c-string test case
* Add missing failing test cases for non-int32_t integral types
ACKs for top commit:
laanwj:
Code review ACK fa9d72a794, good find on ParseDouble not being used at all, and testing for behavior of embedded NULL characters is always a good thing.
practicalswift:
cr ACK fa9d72a794
Tree-SHA512: 3d654dcaebbf312dd57e54241f9aa6d35b1d1d213c37e4c6b8b9a69bcbe8267a397474a8b86b57740fbdd8e3d03b4cdb6a189a9eb8e05cd38035dab195410aa7
