swap: fix htlc address generation

This commit fixes the generation of the htlc address. This bug didn't
affect the swap execution, because the htlc address is only used for
display to the user/caller.

Author: joostjager

swap/htlc.go

@@ -67,15 +67,13 @@ func NewHtlc(cltvExpiry int32, senderKey, receiverKey [33]byte,
 		return nil, err
 	}
 
-	p2wshPkScriptHash := sha256.Sum256(p2wshPkScript)
-
 	var pkScript, sigScript []byte
 	var address btcutil.Address
 
 	switch outputType {
 	case HtlcNP2WSH:
 		// Generate p2sh script for p2wsh (nested).
-
+		p2wshPkScriptHash := sha256.Sum256(p2wshPkScript)
 		hash160 := input.Ripemd160H(p2wshPkScriptHash[:])
 
 		builder := txscript.NewScriptBuilder()
@@ -111,7 +109,7 @@ func NewHtlc(cltvExpiry int32, senderKey, receiverKey [33]byte,
 		pkScript = p2wshPkScript
 
 		address, err = btcutil.NewAddressWitnessScriptHash(
-			p2wshPkScriptHash[:],
+			p2wshPkScript[2:],
 			chainParams,
 		)
 		if err != nil {