contractcourt: update htlcSuccessResolver for taproot chans

contractcourt/htlc_incoming_contest_resolver.go

@@ -8,6 +8,7 @@ import (
 	"io"
 
 	"github.com/btcsuite/btcd/btcutil"
+	"github.com/btcsuite/btcd/txscript"
 	"github.com/lightningnetwork/lnd/channeldb"
 	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/htlcswitch/hop"
@@ -103,9 +104,9 @@ func (h *htlcIncomingContestResolver) Resolve() (ContractResolver, error) {
 
 		// If we've locked in an htlc with an invalid payload on our
 		// commitment tx, we don't need to resolve it. The other party
-		// will time it out and get their funds back. This situation can
-		// present itself when we crash before processRemoteAdds in the
-		// link has ran.
+		// will time it out and get their funds back. This situation
+		// can present itself when we crash before processRemoteAdds in
+		// the link has ran.
 		h.resolved = true
 
 		if err := h.processFinalHtlcFail(); err != nil {
@@ -192,17 +193,41 @@ func (h *htlcIncomingContestResolver) Resolve() (ContractResolver, error) {
 		log.Infof("%T(%v): applied preimage=%v", h,
 			h.htlcResolution.ClaimOutpoint, preimage)
 
+		isSecondLevel := h.htlcResolution.SignedSuccessTx != nil
+
+		// If we didn't have to go to the second level to claim (this
+		// is the remote commitment transaction), then we don't need to
+		// modify our canned witness.
+		if !isSecondLevel {
+			return nil
+		}
+
+		isTaproot := txscript.IsPayToTaproot(
+			h.htlcResolution.SignedSuccessTx.TxOut[0].PkScript,
+		)
+
 		// If this is our commitment transaction, then we'll need to
 		// populate the witness for the second-level HTLC transaction.
-		if h.htlcResolution.SignedSuccessTx != nil {
-			// Within the witness for the success transaction, the
-			// preimage is the 4th element as it looks like:
-			//
-			//  * <sender sig> <recvr sig> <preimage> <witness script>
-			//
-			// We'll populate it within the witness, as since this
-			// was a "contest" resolver, we didn't yet know of the
-			// preimage.
+		switch {
+		// For taproot channels, the witness for sweeping with sucess
+		// looks like:
+		//   - <sender sig> <receiver sig> <preimage> <success_script>
+		//     <control_block>
+		//
+		// So we'll insert it at the 3rd index of the witness.
+		case isTaproot:
+			//nolint:lll
+			h.htlcResolution.SignedSuccessTx.TxIn[0].Witness[2] = preimage[:]
+
+		// Within the witness for the success transaction, the
+		// preimage is the 4th element as it looks like:
+		//
+		//  * <0> <sender sig> <recvr sig> <preimage> <witness script>
+		//
+		// We'll populate it within the witness, as since this
+		// was a "contest" resolver, we didn't yet know of the
+		// preimage.
+		case !isTaproot:
 			h.htlcResolution.SignedSuccessTx.TxIn[0].Witness[3] = preimage[:]
 		}
 

contractcourt/htlc_success_resolver.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/btcsuite/btcd/btcutil"
 	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/txscript"
 	"github.com/btcsuite/btcd/wire"
 	"github.com/davecgh/go-spew/spew"
 	"github.com/lightningnetwork/lnd/chainntnfs"
@@ -14,6 +15,7 @@ import (
 	"github.com/lightningnetwork/lnd/channeldb/models"
 	"github.com/lightningnetwork/lnd/input"
 	"github.com/lightningnetwork/lnd/labels"
+	"github.com/lightningnetwork/lnd/lnutils"
 	"github.com/lightningnetwork/lnd/lnwallet"
 	"github.com/lightningnetwork/lnd/sweep"
 )
@@ -171,9 +173,9 @@ func (h *htlcSuccessResolver) broadcastSuccessTx() (*wire.OutPoint, error) {
 	// If we have non-nil SignDetails, this means that have a 2nd level
 	// HTLC transaction that is signed using sighash SINGLE|ANYONECANPAY
 	// (the case for anchor type channels). In this case we can re-sign it
-	// and attach fees at will. We let the sweeper handle this job.
-	// We use the checkpointed outputIncubating field to determine if we
-	// already swept the HTLC output into the second level transaction.
+	// and attach fees at will. We let the sweeper handle this job.  We use
+	// the checkpointed outputIncubating field to determine if we already
+	// swept the HTLC output into the second level transaction.
 	if h.htlcResolution.SignDetails != nil {
 		return h.broadcastReSignedSuccessTx()
 	}
@@ -233,16 +235,29 @@ func (h *htlcSuccessResolver) broadcastReSignedSuccessTx() (
 
 	// We will have to let the sweeper re-sign the success tx and wait for
 	// it to confirm, if we haven't already.
+	isTaproot := txscript.IsPayToTaproot(
+		h.htlcResolution.SweepSignDesc.Output.PkScript,
+	)
 	if !h.outputIncubating {
 		log.Infof("%T(%x): offering second-layer transition tx to "+
 			"sweeper: %v", h, h.htlc.RHash[:],
 			spew.Sdump(h.htlcResolution.SignedSuccessTx))
 
-		secondLevelInput := input.MakeHtlcSecondLevelSuccessAnchorInput(
-			h.htlcResolution.SignedSuccessTx,
-			h.htlcResolution.SignDetails, h.htlcResolution.Preimage,
-			h.broadcastHeight,
-		)
+		var secondLevelInput input.HtlcSecondLevelAnchorInput
+		if isTaproot {
+			secondLevelInput = input.MakeHtlcSecondLevelSuccessTaprootInput(
+				h.htlcResolution.SignedSuccessTx,
+				h.htlcResolution.SignDetails, h.htlcResolution.Preimage,
+				h.broadcastHeight,
+			)
+		} else {
+			secondLevelInput = input.MakeHtlcSecondLevelSuccessAnchorInput(
+				h.htlcResolution.SignedSuccessTx,
+				h.htlcResolution.SignDetails, h.htlcResolution.Preimage,
+				h.broadcastHeight,
+			)
+		}
+
 		_, err := h.Sweeper.SweepInput(
 			&secondLevelInput,
 			sweep.Params{
@@ -341,13 +356,20 @@ func (h *htlcSuccessResolver) broadcastReSignedSuccessTx() (
 
 	// Let the sweeper sweep the second-level output now that the
 	// CSV/CLTV locks have expired.
+	var witType input.StandardWitnessType
+	if isTaproot {
+		witType = input.TaprootHtlcAcceptedSuccessSecondLevel
+	} else {
+		witType = input.HtlcAcceptedSuccessSecondLevel
+	}
 	inp := h.makeSweepInput(
-		op, input.HtlcAcceptedSuccessSecondLevel,
+		op, witType,
 		input.LeaseHtlcAcceptedSuccessSecondLevel,
 		&h.htlcResolution.SweepSignDesc,
 		h.htlcResolution.CsvDelay, h.broadcastHeight,
 		h.htlc.RHash,
 	)
+	// TODO(roasbeef): need to update above for leased types
 	_, err = h.Sweeper.SweepInput(
 		inp,
 		sweep.Params{
@@ -377,17 +399,32 @@ func (h *htlcSuccessResolver) resolveRemoteCommitOutput() (
 		log.Infof("%T(%x): crafting sweep tx for incoming+remote "+
 			"htlc confirmed", h, h.htlc.RHash[:])
 
+		isTaproot := txscript.IsPayToTaproot(
+			h.htlcResolution.SweepSignDesc.Output.PkScript,
+		)
+
 		// Before we can craft out sweeping transaction, we need to
 		// create an input which contains all the items required to add
 		// this input to a sweeping transaction, and generate a
 		// witness.
-		inp := input.MakeHtlcSucceedInput(
-			&h.htlcResolution.ClaimOutpoint,
-			&h.htlcResolution.SweepSignDesc,
-			h.htlcResolution.Preimage[:],
-			h.broadcastHeight,
-			h.htlcResolution.CsvDelay,
-		)
+		var inp input.Input
+		if isTaproot {
+			inp = lnutils.Ptr(input.MakeTaprootHtlcSucceedInput(
+				&h.htlcResolution.ClaimOutpoint,
+				&h.htlcResolution.SweepSignDesc,
+				h.htlcResolution.Preimage[:],
+				h.broadcastHeight,
+				h.htlcResolution.CsvDelay,
+			))
+		} else {
+			inp = lnutils.Ptr(input.MakeHtlcSucceedInput(
+				&h.htlcResolution.ClaimOutpoint,
+				&h.htlcResolution.SweepSignDesc,
+				h.htlcResolution.Preimage[:],
+				h.broadcastHeight,
+				h.htlcResolution.CsvDelay,
+			))
+		}
 
 		// With the input created, we can now generate the full sweep
 		// transaction, that we'll use to move these coins back into
@@ -400,7 +437,7 @@ func (h *htlcSuccessResolver) resolveRemoteCommitOutput() (
 		// TODO: Use time-based sweeper and result chan.
 		var err error
 		h.sweepTx, err = h.Sweeper.CreateSweepTx(
-			[]input.Input{&inp},
+			[]input.Input{inp},
 			sweep.FeePreference{
 				ConfTarget: sweepConfTarget,
 			}, 0,