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input: create IsHtlcSpendRevoke

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This commit is contained in:
Johan T. Halseth 2021-04-26 15:29:59 +02:00
parent e7ee5ad51f
commit 0a0b5f89c9
No known key found for this signature in database
GPG Key ID: 15BAADA29DA20D26
1 changed files with 40 additions and 20 deletions
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60
input/script_utils.go
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@ -313,21 +313,32 @@ func SenderHtlcSpendRevokeWithKey(signer Signer, signDesc *SignDescriptor,
func SenderHtlcSpendRevoke(signer Signer, signDesc *SignDescriptor, func SenderHtlcSpendRevoke(signer Signer, signDesc *SignDescriptor,
sweepTx *wire.MsgTx) (wire.TxWitness, error) { sweepTx *wire.MsgTx) (wire.TxWitness, error) {
if signDesc.KeyDesc.PubKey == nil { revokeKey, err := deriveRevokePubKey(signDesc)
return nil, fmt.Errorf("cannot generate witness with nil " + if err != nil {
"KeyDesc pubkey") return nil, err
} }
// Derive the revocation key using the local revocation base point and
// commitment point.
revokeKey := DeriveRevocationPubkey(
signDesc.KeyDesc.PubKey,
signDesc.DoubleTweak.PubKey(),
)
return SenderHtlcSpendRevokeWithKey(signer, signDesc, revokeKey, sweepTx) return SenderHtlcSpendRevokeWithKey(signer, signDesc, revokeKey, sweepTx)
} }
// IsHtlcSpendRevoke is used to determine if the passed spend is spending a
// HTLC output using the revocation key.
func IsHtlcSpendRevoke(txIn *wire.TxIn, signDesc *SignDescriptor) (
bool, error) {
revokeKey, err := deriveRevokePubKey(signDesc)
if err != nil {
return false, err
}
if len(txIn.Witness) == 3 &&
bytes.Equal(txIn.Witness[1], revokeKey.SerializeCompressed()) {
return true, nil
}
return false, nil
}
// SenderHtlcSpendRedeem constructs a valid witness allowing the receiver of an // SenderHtlcSpendRedeem constructs a valid witness allowing the receiver of an
// HTLC to redeem the pending output in the scenario that the sender broadcasts // HTLC to redeem the pending output in the scenario that the sender broadcasts
// their version of the commitment transaction. A valid spend requires // their version of the commitment transaction. A valid spend requires
@ -575,16 +586,7 @@ func ReceiverHtlcSpendRevokeWithKey(signer Signer, signDesc *SignDescriptor,
return witnessStack, nil return witnessStack, nil
} }
// ReceiverHtlcSpendRevoke constructs a valid witness allowing the sender of an func deriveRevokePubKey(signDesc *SignDescriptor) (*btcec.PublicKey, error) {
// HTLC within a previously revoked commitment transaction to re-claim the
// pending funds in the case that the receiver broadcasts this revoked
// commitment transaction. This method first derives the appropriate revocation
// key, and requires that the provided SignDescriptor has a local revocation
// basepoint and commitment secret in the PubKey and DoubleTweak fields,
// respectively.
func ReceiverHtlcSpendRevoke(signer Signer, signDesc *SignDescriptor,
sweepTx *wire.MsgTx) (wire.TxWitness, error) {
if signDesc.KeyDesc.PubKey == nil { if signDesc.KeyDesc.PubKey == nil {
return nil, fmt.Errorf("cannot generate witness with nil " + return nil, fmt.Errorf("cannot generate witness with nil " +
"KeyDesc pubkey") "KeyDesc pubkey")
@ -597,6 +599,24 @@ func ReceiverHtlcSpendRevoke(signer Signer, signDesc *SignDescriptor,
signDesc.DoubleTweak.PubKey(), signDesc.DoubleTweak.PubKey(),
) )
return revokeKey, nil
}
// ReceiverHtlcSpendRevoke constructs a valid witness allowing the sender of an
// HTLC within a previously revoked commitment transaction to re-claim the
// pending funds in the case that the receiver broadcasts this revoked
// commitment transaction. This method first derives the appropriate revocation
// key, and requires that the provided SignDescriptor has a local revocation
// basepoint and commitment secret in the PubKey and DoubleTweak fields,
// respectively.
func ReceiverHtlcSpendRevoke(signer Signer, signDesc *SignDescriptor,
sweepTx *wire.MsgTx) (wire.TxWitness, error) {
revokeKey, err := deriveRevokePubKey(signDesc)
if err != nil {
return nil, err
}
return ReceiverHtlcSpendRevokeWithKey(signer, signDesc, revokeKey, sweepTx) return ReceiverHtlcSpendRevokeWithKey(signer, signDesc, revokeKey, sweepTx)
} }