Implement message signing for Taproot

[andrewkozlik]

First we need to decide how to deal with Taproot addresses in SignMessage and VerifyMessage, what to hash and whether to tweak the keys. Bitcoin Core supports message signing only for legacy addresses. Other wallets either don't support Taproot at all or they don't implement message signing for Taproot addresses. We will wait with the implementation in Trezor until there is some consensus in the community about the way this should work.

Some resources mention using BIP-322, but the specification still isn't finished and the last time we used BIP-322 for ownership proofs in SLIP-19, the whole BIP-322 specification got rewritten.
https://bitcoinops.org/en/topics/generic-signmessage/
https://bitcoinops.org/en/newsletters/2021/09/29/#preparing-for-taproot-15-signmessage-protocol-still-needed

This is also related to AOPP: https://github.com/trezor/trezor-firmware/issues/1586.

[mmilata]

There seems to be active effort getting BIP-322 support into Bitcoin Core: bitcoin/bitcoin#24058.

[AlexanderPavlenko]

Will implementing this also add support for Nostr events sign/verify? Seems like a nice to have feature.
NIP-01: "Signatures, public key, and encodings are done according to the Schnorr signatures standard for the
curve secp256k1".

# test mnemonic from NIP-06: leader monkey parrot ring guide accident before fence cannon height naive bean
trezorctl device recover
trezorctl set safety-checks prompt
trezorctl btc sign-message -t taproot -n "m/44'/1237'/0'/0/0" '[0,"17162c921dc4d2518f9a101db33695df1afb56ab82f5ff3e5da6eec3ca5cd917",1703260028,1,[],"hello world"]'

Expected result close to "sig": "9c3ba7ca1b4942f784c014b28779c4a904c902c75104fc0ae72485d0dfac27ce95e1178cc33eb86d4d86ec354004a77e965553dfafb01f47733a6b31d79cc56c", got Error: ProcessError: Unsupported script type instead.

[psychoet]

No more update on this?

[Hannsek]

Not yet…