tapchannelmsg: include stxo flag in commitment blob

We extend the commitment blob to also store a flag, indicating whether
STXO was active when that commitment was created. This can be useful for
future sweeps that need to know whether that commitment used stxo alt
leaves, which affects the reconstruction of the tap commitment.

Author: GeorgeTsagk

rfq/manager_test.go

@@ -111,6 +111,7 @@ func createChannelWithCustomData(t *testing.T, id asset.ID, localBalance,
 				),
 			},
 			nil, nil, lnwallet.CommitAuxLeaves{},
+			false,
 		),
 		OpenChan: *tpchmsg.NewOpenChannel(
 			[]*tpchmsg.AssetOutput{

tapchannel/auf_leaf_signer_test.go

@@ -111,7 +111,7 @@ func setupAuxLeafSigner(t *testing.T, numJobs int32) (*AuxLeafSigner,
 	}
 
 	com := cmsg.NewCommitment(
-		nil, nil, outgoingHtlcs, nil, lnwallet.CommitAuxLeaves{},
+		nil, nil, outgoingHtlcs, nil, lnwallet.CommitAuxLeaves{}, false,
 	)
 	cancelChan := make(chan struct{})
 

tapchannel/aux_funding_controller.go

@@ -587,6 +587,7 @@ func newCommitBlobAndLeaves(pendingFunding *pendingAssetFunding,
 	// needs the sum of the remote+local assets, so we'll populate that.
 	fakePrevState := cmsg.NewCommitment(
 		localAssets, remoteAssets, nil, nil, lnwallet.CommitAuxLeaves{},
+		stxo,
 	)
 
 	// Just like above, we don't have a real HTLC view here, so we'll pass

tapchannel/commitment.go

@@ -651,7 +651,7 @@ func GenerateCommitmentAllocations(prevState *cmsg.Commitment,
 	// Next, we can convert the allocations to auxiliary leaves and from
 	// those construct our Commitment struct that will in the end also hold
 	// our proof suffixes.
-	newCommitment, err := ToCommitment(allocations, vPackets)
+	newCommitment, err := ToCommitment(allocations, vPackets, stxo)
 	if err != nil {
 		return nil, nil, fmt.Errorf("unable to convert to commitment: "+
 			"%w", err)
@@ -1155,7 +1155,7 @@ func LeavesFromTapscriptScriptTree(
 
 // ToCommitment converts the allocations to a Commitment struct.
 func ToCommitment(allocations []*tapsend.Allocation,
-	vPackets []*tappsbt.VPacket) (*cmsg.Commitment, error) {
+	vPackets []*tappsbt.VPacket, stxo bool) (*cmsg.Commitment, error) {
 
 	var (
 		localAssets   []*cmsg.AssetOutput
@@ -1278,7 +1278,7 @@ func ToCommitment(allocations []*tapsend.Allocation,
 
 	return cmsg.NewCommitment(
 		localAssets, remoteAssets, outgoingHtlcs, incomingHtlcs,
-		auxLeaves,
+		auxLeaves, stxo,
 	), nil
 }
 

tapchannelmsg/custom_channel_data_test.go

@@ -50,6 +50,7 @@ func TestReadChannelCustomData(t *testing.T) {
 		}, map[input.HtlcIndex][]*AssetOutput{
 			2: {output4},
 		}, lnwallet.CommitAuxLeaves{},
+		false,
 	)
 
 	fundingBlob := fundingState.Bytes()
@@ -157,19 +158,19 @@ func TestReadBalanceCustomData(t *testing.T) {
 
 	openChannel1 := NewCommitment(
 		[]*AssetOutput{output1}, []*AssetOutput{output2}, nil, nil,
-		lnwallet.CommitAuxLeaves{},
+		lnwallet.CommitAuxLeaves{}, false,
 	)
 	openChannel2 := NewCommitment(
 		[]*AssetOutput{output2}, []*AssetOutput{output3}, nil, nil,
-		lnwallet.CommitAuxLeaves{},
+		lnwallet.CommitAuxLeaves{}, false,
 	)
 	pendingChannel1 := NewCommitment(
 		[]*AssetOutput{output3}, nil, nil, nil,
-		lnwallet.CommitAuxLeaves{},
+		lnwallet.CommitAuxLeaves{}, false,
 	)
 	pendingChannel2 := NewCommitment(
 		nil, []*AssetOutput{output1}, nil, nil,
-		lnwallet.CommitAuxLeaves{},
+		lnwallet.CommitAuxLeaves{}, false,
 	)
 
 	var customChannelData bytes.Buffer

tapchannelmsg/records.go

@@ -453,13 +453,17 @@ type Commitment struct {
 
 	// AuxLeaves are the auxiliary leaves that correspond to the commitment.
 	AuxLeaves tlv.RecordT[tlv.TlvType4, AuxLeaves]
+
+	// STXO is a flag indicating whether this commitment supports stxo
+	// proofs.
+	STXO tlv.RecordT[tlv.TlvType5, bool]
 }
 
 // NewCommitment creates a new Commitment record with the given local and remote
 // assets, and incoming and outgoing HTLCs.
 func NewCommitment(localAssets, remoteAssets []*AssetOutput, outgoingHtlcs,
 	incomingHtlcs map[input.HtlcIndex][]*AssetOutput,
-	auxLeaves lnwallet.CommitAuxLeaves) *Commitment {
+	auxLeaves lnwallet.CommitAuxLeaves, stxo bool) *Commitment {
 
 	return &Commitment{
 		LocalAssets: tlv.NewRecordT[tlv.TlvType0](
@@ -485,6 +489,7 @@ func NewCommitment(localAssets, remoteAssets []*AssetOutput, outgoingHtlcs,
 				auxLeaves.IncomingHtlcLeaves,
 			),
 		),
+		STXO: tlv.NewPrimitiveRecord[tlv.TlvType5](stxo),
 	}
 }
 
@@ -496,6 +501,7 @@ func (c *Commitment) records() []tlv.Record {
 		c.OutgoingHtlcAssets.Record(),
 		c.IncomingHtlcAssets.Record(),
 		c.AuxLeaves.Record(),
+		c.STXO.Record(),
 	}
 }
 

tapchannelmsg/records_test.go

@@ -215,6 +215,7 @@ func TestCommitment(t *testing.T) {
 			name: "commitment with empty HTLC maps",
 			commitment: NewCommitment(
 				nil, nil, nil, nil, lnwallet.CommitAuxLeaves{},
+				false,
 			),
 		},
 		{
@@ -228,7 +229,21 @@ func TestCommitment(t *testing.T) {
 					NewAssetOutput(
 						[32]byte{1}, 1000, *randProof,
 					),
-				}, nil, nil, lnwallet.CommitAuxLeaves{},
+				}, nil, nil, lnwallet.CommitAuxLeaves{}, false,
+			),
+		},
+		{
+			name: "commitment with balances and stxo",
+			commitment: NewCommitment(
+				[]*AssetOutput{
+					NewAssetOutput(
+						[32]byte{1}, 1000, *randProof,
+					),
+				}, []*AssetOutput{
+					NewAssetOutput(
+						[32]byte{1}, 1000, *randProof,
+					),
+				}, nil, nil, lnwallet.CommitAuxLeaves{}, true,
 			),
 		},
 		{
@@ -319,6 +334,7 @@ func TestCommitment(t *testing.T) {
 						},
 					},
 				},
+				false,
 			),
 		},
 	}