multi: disable STXO proof generation for channels

Since we already disable creating the STXO commitments for TAP channels,
we also need to disable creating the proofs for them, as they would be
invalid anyway.

Author: guggero

proof/append.go

@@ -14,15 +14,19 @@ import (
 // GenConfig is a struct that holds the configuration for creating Taproot Asset
 // proofs.
 type GenConfig struct {
-	// transitionVersion is the version of the asset state transition proof
+	// TransitionVersion is the version of the asset state transition proof
 	// that is going to be used.
-	transitionVersion TransitionVersion
+	TransitionVersion TransitionVersion
+
+	// NoSTXOProofs indicates whether to skip the generation of STXO
+	// inclusion and exclusion proofs for the transition proof.
+	NoSTXOProofs bool
 }
 
 // DefaultGenConfig returns a default proof generation configuration.
 func DefaultGenConfig() GenConfig {
 	return GenConfig{
-		transitionVersion: TransitionV0,
+		TransitionVersion: TransitionV0,
 	}
 }
 
@@ -34,7 +38,15 @@ type GenOption func(*GenConfig)
 // given version.
 func WithVersion(v TransitionVersion) GenOption {
 	return func(cfg *GenConfig) {
-		cfg.transitionVersion = v
+		cfg.TransitionVersion = v
+	}
+}
+
+// WithNoSTXOProofs is an option that can be used to skip the generation of
+// STXO inclusion and exclusion proofs for the transition proof.
+func WithNoSTXOProofs() GenOption {
+	return func(cfg *GenConfig) {
+		cfg.NoSTXOProofs = true
 	}
 }
 
@@ -158,7 +170,7 @@ func CreateTransitionProof(prevOut wire.OutPoint, params *TransitionParams,
 	}
 
 	proof, err := baseProof(
-		&params.BaseProofParams, prevOut, cfg.transitionVersion,
+		&params.BaseProofParams, prevOut, cfg.TransitionVersion,
 	)
 	if err != nil {
 		return nil, fmt.Errorf("error creating base proofs: %w", err)
@@ -194,7 +206,7 @@ func CreateTransitionProof(prevOut wire.OutPoint, params *TransitionParams,
 		TapSiblingPreimage: params.TapscriptSibling,
 	}
 
-	if proof.Asset.IsTransferRoot() {
+	if proof.Asset.IsTransferRoot() && !cfg.NoSTXOProofs {
 		stxoInclusionProofs := make(
 			map[asset.SerializedKey]commitment.Proof,
 			len(proof.Asset.PrevWitnesses),

proof/mint.go

@@ -266,7 +266,7 @@ func NewMintingBlobs(params *MintParams, vCtx VerifierCtx,
 
 	base, err := baseProof(
 		&params.BaseProofParams, params.GenesisPoint,
-		opts.genConfig.transitionVersion,
+		opts.genConfig.TransitionVersion,
 	)
 	if err != nil {
 		return nil, err

tapchannel/aux_closer.go

@@ -726,6 +726,7 @@ func (a *AuxChanCloser) FinalizeClose(desc chancloser.AuxCloseDesc,
 			proofSuffix, err := tapsend.CreateProofSuffixCustom(
 				closeTx, vPkt, closeInfo.outputCommitments,
 				outIdx, closeInfo.vPackets, exclusionCreator,
+				proof.WithNoSTXOProofs(),
 			)
 			if err != nil {
 				return fmt.Errorf("unable to create proof "+

tapchannel/aux_funding_controller.go

@@ -1114,6 +1114,7 @@ func (f *FundingController) anchorVPackets(fundedPkt *tapsend.FundedPsbt,
 			proofSuffix, err := tapsend.CreateProofSuffix(
 				fundedPkt.Pkt.UnsignedTx, fundedPkt.Pkt.Outputs,
 				vPkt, outputCommitments, vOutIdx, allPackets,
+				proof.WithNoSTXOProofs(),
 			)
 			if err != nil {
 				return nil, fmt.Errorf("unable to create "+

tapchannel/aux_sweeper.go

@@ -1612,6 +1612,7 @@ func (a *AuxSweeper) importCommitTx(req lnwallet.ResolutionReq,
 			proofSuffix, err := tapsend.CreateProofSuffixCustom(
 				req.CommitTx, vPkt, outCommitments, outIdx,
 				vPackets, exclusionCreator,
+				proof.WithNoSTXOProofs(),
 			)
 			if err != nil {
 				return fmt.Errorf("unable to create "+
@@ -2450,7 +2451,7 @@ func (a *AuxSweeper) registerAndBroadcastSweep(req *sweep.BumpRequest,
 
 			proofSuffix, err := tapsend.CreateProofSuffixCustom(
 				sweepTx, vPkt, outCommitments, outIdx, allVpkts,
-				exclusionCreator,
+				exclusionCreator, proof.WithNoSTXOProofs(),
 			)
 			if err != nil {
 				return fmt.Errorf("unable to create proof "+

tapchannel/commitment.go

@@ -612,7 +612,7 @@ func GenerateCommitmentAllocations(prevState *cmsg.Commitment,
 				fakeCommitTx, vPkt, outCommitments, outIdx,
 				vPackets, tapsend.NonAssetExclusionProofs(
 					allocations,
-				),
+				), proof.WithNoSTXOProofs(),
 			)
 			if err != nil {
 				return nil, nil, fmt.Errorf("unable to create "+

tapsend/proof.go

@@ -155,9 +155,14 @@ func CreateProofSuffixCustom(finalTx *wire.MsgTx, vPacket *tappsbt.VPacket,
 
 	inputPrevID := vPacket.Inputs[0].PrevID
 
+	cfg := proof.DefaultGenConfig()
+	for _, opt := range opts {
+		opt(&cfg)
+	}
+
 	params, err := proofParams(
 		finalTx, vPacket, outputCommitments, outIndex,
-		allAnchoredVPackets,
+		allAnchoredVPackets, cfg.NoSTXOProofs,
 	)
 	if err != nil {
 		return nil, err
@@ -233,7 +238,8 @@ func newParams(finalTx *wire.MsgTx, a *asset.Asset, outputIndex int,
 // proofs for the sender and receiver.
 func proofParams(finalTx *wire.MsgTx, vPkt *tappsbt.VPacket,
 	outputCommitments tappsbt.OutputCommitments, outIndex int,
-	allAnchoredVPackets []*tappsbt.VPacket) (*proof.TransitionParams, error) {
+	allAnchoredVPackets []*tappsbt.VPacket,
+	noStxoProofs bool) (*proof.TransitionParams, error) {
 
 	isSplit, err := vPkt.HasSplitCommitment()
 	if err != nil {
@@ -269,6 +275,12 @@ func proofParams(finalTx *wire.MsgTx, vPkt *tappsbt.VPacket,
 			outputCommitments,
 		)
 
+		// If we don't require STXO exclusion proofs, then we are done
+		// here.
+		if noStxoProofs {
+			return rootParams, err
+		}
+
 		// Add STXO exclusion proofs for all the other outputs, for all
 		// STXOs spent by _all_ VOutputs that anchor in this output.
 		// First Collect all STXOs for this anchor output. Then add