Fix multisig path for sweeptimelockremote

Author: RocketNodeLN

cmd/chantools/sweeptimelockmanual.go

@@ -167,6 +167,7 @@ func (c *sweepTimeLockManualCommand) Execute(_ *cobra.Command, _ []string) error
 		startNumChannelsTotal     uint16
 		maxNumChannelsTotal       = c.MaxNumChannelsTotal
 		remoteRevocationBasePoint = c.RemoteRevocationBasePoint
+		multiSigIdx               uint32
 	)
 
 	// We either support specifying the remote revocation base point
@@ -210,7 +211,16 @@ func (c *sweepTimeLockManualCommand) Execute(_ *cobra.Command, _ []string) error
 
 		startNumChannelsTotal = uint16(delayPath[4])
 		maxNumChannelsTotal = startNumChannelsTotal + 1
-
+		multiSigKeyPath, err := lnd.ParsePath(
+			backupChan.LocalChanCfg.MultiSigKey.Path,
+		)
+		if err != nil {
+			return fmt.Errorf("error parsing multisigkey path: %w", err)
+		}
+		if len(multiSigKeyPath) != 5 {
+			return fmt.Errorf("invalid delay path '%v'", multiSigKeyPath)
+		}
+		multiSigIdx = multiSigKeyPath[4]
 	case c.ChannelBackup != "" && c.RemoteRevocationBasePoint != "":
 		return errors.New("cannot use both --frombackup and " +
 			"--remoterevbasepoint at the same time")
@@ -230,14 +240,14 @@ func (c *sweepTimeLockManualCommand) Execute(_ *cobra.Command, _ []string) error
 
 	return sweepTimeLockManual(
 		extendedKey, c.APIURL, c.SweepAddr, c.TimeLockAddr,
-		remoteRevPoint, startCsvLimit, maxCsvLimit,
+		remoteRevPoint, multiSigIdx, startCsvLimit, maxCsvLimit,
 		startNumChannelsTotal, maxNumChannelsTotal,
 		c.MaxNumChanUpdates, c.Publish, c.FeeRate,
 	)
 }
 
 func sweepTimeLockManual(extendedKey *hdkeychain.ExtendedKey, apiURL string,
-	sweepAddr, timeLockAddr string, remoteRevPoint *btcec.PublicKey,
+	sweepAddr, timeLockAddr string, remoteRevPoint *btcec.PublicKey, multiSigIdx uint32,
 	startCsvTimeout, maxCsvTimeout, startNumChannels, maxNumChannels uint16,
 	maxNumChanUpdates uint64, publish bool, feeRate uint32) error {
 
@@ -302,7 +312,7 @@ func sweepTimeLockManual(extendedKey *hdkeychain.ExtendedKey, apiURL string,
 	)
 	for i := startNumChannels; i < maxNumChannels; i++ {
 		csvTimeout, script, scriptHash, commitPoint, delayDesc, err = tryKey(
-			baseKey, remoteRevPoint, startCsvTimeout, maxCsvTimeout,
+			baseKey, remoteRevPoint, multiSigIdx, startCsvTimeout, maxCsvTimeout,
 			lockScript, uint32(i), maxNumChanUpdates,
 		)
 
@@ -413,7 +423,7 @@ func sweepTimeLockManual(extendedKey *hdkeychain.ExtendedKey, apiURL string,
 }
 
 func tryKey(baseKey *hdkeychain.ExtendedKey, remoteRevPoint *btcec.PublicKey,
-	startCsvTimeout, maxCsvTimeout uint16, lockScript []byte, idx uint32,
+	multiSigIdx uint32, startCsvTimeout, maxCsvTimeout uint16, lockScript []byte, idx uint32,
 	maxNumChanUpdates uint64) (int32, []byte, []byte, *btcec.PublicKey,
 	*keychain.KeyDescriptor, error) {
 
@@ -491,11 +501,13 @@ func tryKey(baseKey *hdkeychain.ExtendedKey, remoteRevPoint *btcec.PublicKey,
 			keychain.KeyFamilyRevocationRoot,
 		)), 0, idx,
 	}
-
+	if multiSigIdx == 0 {
+		multiSigIdx = idx
+	}
 	// Now we try the same with the new revocation producer format.
 	multiSigPath := []uint32{
 		lnd.HardenedKey(uint32(keychain.KeyFamilyMultiSig)),
-		0, idx,
+		0, multiSigIdx,
 	}
 	multiSigPrivKey, err := lnd.PrivKeyFromPath(baseKey, multiSigPath)
 	if err != nil {