KarpelesLab / libwallet / 25269529660

24%

push

github

wlttx/bitcoin: return *secp256k1.PublicKey from btcInputSigner.Public

outscript's pubkey:comp generator (used to build the spending
pubkey embed in p2pkh / p2sh:p2wpkh / p2wpkh witnesses, see
btctx.go:143/188/268) requires a type that satisfies
interface{ SerializeCompressed() []byte }. *ecdsa.PublicKey
carries the right curve points but not that method, so signing
any non-p2wpkh input failed with:

  build bitcoin tx: tx sign: pubkey of type *ecdsa.PublicKey
  does not support pubkey:comp export

The latent bug was masked until 0.4.10 because coin selection
only ever fetched m/0 (which the wallet only emits as p2wpkh on
litecoin / bitcoin / monacoin), so the witness path that calls
pubkey:comp didn't fire. With m/0+m/1 in the mix, the first
spend that touches a legacy or wrapped-segwit UTXO trips it.

Fix: return childPub directly — *secp256k1.PublicKey has
SerializeCompressed() built in.

Test pins the Public() return type via interface assertion so a
future "let's give callers a stdlib-friendly *ecdsa.PublicKey"
refactor gets caught at test time, not in production.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

10 of 10 new or added lines in 1 file covered. (100.0%)

3121 of 15163 relevant lines covered (20.58%)

125.92 hits per line