There are several instances in functional tests and the framework
(MiniWallet, feature_block.py, p2p_segwit.py) where we create a legacy
ECDSA signature for a certain transaction's input by doing the following
steps:
1) calculate the `LegacySignatureHash` with the desired sighash type
2) create the actual digital signature by calling `ECKey.sign_ecdsa`
on the signature message hash calculated above
3) put the DER-encoded result as CScript data push into
tx input's scriptSig
Create a new helper `sign_input_legacy` which hides those details and
takes only the necessary parameters (tx, input index, relevant
scriptPubKey, private key, sighash type [SIGHASH_ALL by default]). For
further convenience, the signature is prepended to already existing
data-pushes in scriptSig, in order to avoid rehashing the transaction
after calling the new signing function.
d6fc1d6a33 test: add coverage for dust mempool policy (`-dustrelayfee` setting) (Sebastian Falbesoner)
8a5dbe2879 test: add `CScript` method for checking for witness program (Sebastian Falbesoner)
Pull request description:
This PR adds missing test coverage for the `-dustrelayfee` setting, which specifies the fee-rate used to define dust. Output scripts for all common types that are treated as standard by default (P2PK, P2(W)PKH, P2(W)SH, P2TR, bare multisig, null data, unknown witness versions v2+) are created and then checked for dust-mempool-policy each via the `testmempoolaccept` RPC: a tx with an output's nValue equal to the dust threshold should be accepted, one with an nValue of just one 1 satoshi below that should be rejected with reason `dust`. This is repeatedly done for a fixed (but obviously somewhat arbitrary) list of different `-dustrelayfee` settings on a single node, including the default and zero (i.e. no dust limit) settings.
Note that the first commit introduces a necessary `CScript` helper method `IsWitnessProgram` (using PascalCase in Python is likely controversial; in this case the style for the already existing method `GetSigOpCount` was followed, which also refers to a method in the core `CScript` class).
Some historical information about dust, contributed by pablomartin4btc:
"The concept of dust was first introduced in https://github.com/bitcoin/bitcoin/pull/2577. This [commit](https://github.com/bitcoin/bitcoin/pull/9380/commits/eb30d1a5b215c6dd3763d7f7948f2dd8cb61f6bf) from https://github.com/bitcoin/bitcoin/pull/9380 introduced the -dustrelayfee option. Previous to that PR, the dust feerate was whatever -minrelaytxfee was set to."
ACKs for top commit:
LarryRuane:
ACK d6fc1d6a33
glozow:
ACK d6fc1d6a33
kouloumos:
ACK d6fc1d6a33
Tree-SHA512: 35ea2b2497dfb466395af5665bb217f7250aa7cab9dc43539a5658ab69a454e3623ff58fce7489fcc1105b37f8cb4840a93cec658c5df1de611732bc6439ccad
The previous diff touched most files in ./test/, so bump the headers to
avoid having to touch them again for a bump later.
-BEGIN VERIFY SCRIPT-
./contrib/devtools/copyright_header.py update ./test/
-END VERIFY SCRIPT-
Messy merge conflicts because this PR backported some ad-hoc stuff from
upstream while keeping a few things that upstream deleted. Hopefully
reviewing is easier than doing this in the first place, since ultimately
all I did was delete code from one side or another of the conflicts.
(Ok, I also changed some boost optional stuff to std::optional, and had
to patch up a test file for test framework changes.)
When reviewing the detailed crypto, bear in mind that taptweaks, like all
hashes are the kind of crypto that cannot be subtly wrong -- it will either
fail very hard or be correct. And we have independent implementations in
C++ and Python that cross-check each other, si it's unlikely to be the former.
This forward-ports the new Taproot sighash but does not fix a couple
22-blocked TODOs related to the MissingDataBehavior enum. Should be fixed
in a followup commit.
One nontrivial change I had to make was feeding the genesis hash to SignTransaction
(the "global" one in script/sign.cpp) so that it could correctly compute
the sighash at signing time.
Several conflicts in the C++ code related to the new `flags` parameter
to `CheckSignature` and the corresponding function being renamed upstream
to `CheckSignatureECDSA`.
Several conflicts in the test harness as Steven sorta pulled the new
upstream ECKey module into the Python code, and the actual upstream
code was slightly different. Also needed to update the feature_taproot
code to always use the non-RANGEPROOF sighash since dynafed is not
enabled in the Taproot test.
Also had to pull the `set_wif` method out of `ECKey` and inline it because
otherwise it triggers a "circular inclusion" error between script.py (which
would pull in `base58_to_bytes` from address.py) and address.py (which now
pulls in some taproot EC related stuff from script.py).
Noticed that #960 does not test the "sighash rangeproof flag set but no
witnesses" case.
