descriptors: MuSig2 #31244

1. 
   achow101 commented at 6:10 pm on November 7, 2024: member

   Implements parsing of BIP 328 musig() descriptors.

   Depends on #31243

   Split from #29675

2. wallet, rpc: Only allow keypool import from single key descriptors

   Instead of relying on implicit assumptions about whether pubkeys show up
   or now after expanding a descriptor, just explicitly allow only single
   key descriptors to import keys into a legacy wallet's keypool.

   75d34b8f71
3. descriptors: Have GetPubKey fill origins directly

   Instead of having ExpandHelper fill in the origins in the
   FlatSigningProvider output, have GetPubKey do it by itself. This reduces
   the extra variables needed in order to track and set origins in
   ExpandHelper.
   
   Also changes GetPubKey to return a std::optional<CPubKey> rather than
   using a bool and output parameters.

   ab8b53c68a
4. descriptors: Move FlatSigningProvider pubkey filling to GetPubKey

   Instead of MakeScripts inconsistently filling the output
   FlatSigningProvider with the pubkeys involved, just do it in GetPubKey.

   decb7a688a
5. descriptors: Have GetPrivKey fill keys directly

   Instead of GetPrivKey returning a key and having the caller fill the
   FlatSigningProvider, have GetPrivKey take the FlatSigningProvider and
   fill it by itself.
   
   GetPrivKey is now changed to void as the caller no longer cares whether
   it succeeds or fails.

   c89d7baaef
6. XOnlyPubKey: Add GetCPubKeys

   We need to retrieve the even and odd compressed pubkeys for xonly
   pubkeys, so add a function to do that. Also reuse it in GetKeyIDs.

   f232f37884
7. spanparsing: Allow Const to not skip the found constant f56f146e1e
8. descriptors: Add PubkeyProvider::IsBIP32() febba96213
9. build: Enable secp256k1 musig module f21d6a17ce
10. sign: Add GetAggregateParticipantPubkeys to SigningProvider 1f828dc01a
11. Add MuSig2 Keyagg Cache class and functions

    - MuSig2KeyAggCache contains a MuSig2KeyAggCacheImpl which has the
      secp256ke_musig_keyagg_cache object to avoid having to link libsecp256k1
      everywhere.
    - GetMuSig2KeyAggCache creates the MuSig2KeyAggCache from a
      std::vector<CPubKey>
    - GetCPubKeyFromMuSig2KeyAggCache creates a CPubKey from a cache created
      with GetMuSig2KeyAggCache
    - MuSig2AggregatePubKeys does the two above functions together.

    257a32b4a9
12. descriptor: Add MuSigPubkeyProvider 0824bd95cd
13. descriptor: Parse musig() key expressions 70f8c40df8
14. tests: Test musig() parsing b352c6e3b9
15. 
    DrahtBot commented at 6:10 pm on November 7, 2024: contributor

    The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

    Code Coverage & Benchmarks

    For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/31244.

    Reviews

    See the guideline for information on the review process. A summary of reviews will appear here.

    Conflicts

    Reviewers, this pull request conflicts with the following ones:

    • #31243 (descriptor: Move filling of keys from DescriptorImpl::MakeScripts to PubkeyProvider::GetPubKey by achow101)
    • #30243 (Tr partial descriptors by Eunovo)
    • #29675 (wallet: Be able to receive and spend inputs involving MuSig2 aggregate keys by achow101)

    If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

16. DrahtBot added the label Descriptors on Nov 7, 2024

Contributors
achow101 DrahtBot

Labels
Descriptors