ac599c4a9c test: Test MuSig2 in the wallet (Ava Chow)
68ef954c4c wallet: Keep secnonces in DescriptorScriptPubKeyMan (Ava Chow)
4a273edda0 sign: Create MuSig2 signatures for known MuSig2 aggregate keys (Ava Chow)
258db93889 sign: Add CreateMuSig2AggregateSig (Ava Chow)
bf69442b3f sign: Add CreateMuSig2PartialSig (Ava Chow)
512b17fc56 sign: Add CreateMuSig2Nonce (Ava Chow)
82ea67c607 musig: Add MuSig2AggregatePubkeys variant that validates the aggregate (Ava Chow)
d99a081679 psbt: MuSig2 data in Fill/FromSignatureData (Ava Chow)
4d8b4f5336 signingprovider: Add musig2 secnonces (Ava Chow)
c06a1dc86f Add MuSig2SecNonce class for secure allocation of musig nonces (Ava Chow)
9baff05e49 sign: Include taproot output key's KeyOriginInfo in sigdata (Ava Chow)
4b24bfeab9 pubkey: Return tweaks from BIP32 derivation (Ava Chow)
f14876213a musig: Move synthetic xpub construction to its own function (Ava Chow)
fb8720f1e0 sign: Refactor Schnorr sighash computation out of CreateSchnorrSig (Ava Chow)
a4cfddda64 tests: Clarify why musig derivation adds a pubkey and xpub (Ava Chow)
39a63bf2e7 descriptors: Add a doxygen comment for has_hardened output_parameter (Ava Chow)
2320184d0e descriptors: Fix meaning of any_key_parsed (Ava Chow)
Pull request description:
This PR implements MuSig2 signing so that the wallet can receive and spend from imported `musig(0` descriptors.
The libsecp musig module is enabled so that it can be used for all of the MuSig2 cryptography.
Secnonces are handled in a separate class which holds the libsecp secnonce object in a `secure_unique_ptr`. Since secnonces must not be used, this class has no serialization and will only live in memory. A restart of the software will require a restart of the MuSig2 signing process.
ACKs for top commit:
fjahr:
tACK ac599c4a9c
rkrux:
lgtm tACK ac599c4a9c
theStack:
Code-review ACK ac599c4a9c🗝️
Tree-SHA512: 626b9adc42ed2403e2f4405321eb9ce009a829c07d968e95ab288fe4940b195b0af35ca279a4a7fa51af76e55382bad6f63a23bca14a84140559b3c667e7041e
A common pattern that MuSig2 functions will use is to aggregate the
pubkeys to get the keyagg_cache and then validate the aggregated pubkey
against a provided aggregate pubkey. A variant of MuSig2AggregatePubkeys
is added which does that.
The functionality of GetMuSig2KeyAggCache and GetCPubKeyFromMuSig2KeyAggCache
are included in MuSig2AggregatePubkeys (and used internally) so there is
no expectation that callers will need these so they are made static.
secp256k1 provides us secp256k1_musig_keyagg_cache objects which we are
used as part of session info and to get the aggregate pubkey. These
helper functions help us convert to/from the secp256k1 C objects into
the Bitcoin Core C++ objects.
