From 80915d9865dfeeb24eff4fed8ccf3e695b20f173 Mon Sep 17 00:00:00 2001
From: tecnovert <tecnovert@tecnovert.net>
Date: Sun, 11 May 2025 11:59:19 +0200
Subject: [PATCH] Deduplicate getP2SHScriptForHash

---
 basicswap/basicswap.py      |  5 +----
 basicswap/interface/btc.py  |  3 +++
 basicswap/interface/part.py | 10 ++++------
 basicswap/util/script.py    | 10 +---------
 4 files changed, 9 insertions(+), 19 deletions(-)

diff --git a/basicswap/basicswap.py b/basicswap/basicswap.py
index dca3f20..083b255 100644
--- a/basicswap/basicswap.py
+++ b/basicswap/basicswap.py
@@ -50,9 +50,6 @@ from .util import (
     make_int,
     ensure,
 )
-from .util.script import (
-    getP2SHScriptForHash,
-)
 from .util.address import (
     toWIF,
     decodeWif,
@@ -4536,7 +4533,7 @@ class BasicSwap(BaseApp):
             prev_p2wsh = ci.getScriptDest(txn_script)
             script_pub_key = prev_p2wsh.hex()
         else:
-            script_pub_key = getP2SHScriptForHash(ci.pkh(txn_script)).hex()
+            script_pub_key = ci.get_p2sh_script_pubkey(txn_script).hex()
 
         prevout = {
             "txid": prev_txnid,
diff --git a/basicswap/interface/btc.py b/basicswap/interface/btc.py
index 04abd5f..a31dd9e 100644
--- a/basicswap/interface/btc.py
+++ b/basicswap/interface/btc.py
@@ -1393,6 +1393,9 @@ class BTCInterface(Secp256k1Interface):
     def getScriptDest(self, script):
         return CScript([OP_0, sha256(script)])
 
+    def getP2WSHScriptDest(self, script):
+        return CScript([OP_0, sha256(script)])
+
     def getScriptScriptSig(self, script: bytes) -> bytes:
         return bytes()
 
diff --git a/basicswap/interface/part.py b/basicswap/interface/part.py
index 10c481c..15c5660 100644
--- a/basicswap/interface/part.py
+++ b/basicswap/interface/part.py
@@ -14,7 +14,6 @@ from basicswap.contrib.test_framework.messages import (
 )
 from basicswap.contrib.test_framework.script import (
     CScript,
-    OP_0,
     OP_DUP,
     OP_HASH160,
     OP_EQUALVERIFY,
@@ -25,7 +24,6 @@ from basicswap.util import (
     TemporaryError,
 )
 from basicswap.util.script import (
-    getP2WSH,
     getCompactSizeLen,
     getWitnessElementLen,
 )
@@ -256,7 +254,7 @@ class PARTInterfaceBlind(PARTInterface):
         ephemeral_pubkey = self.getPubkey(ephemeral_key)
         assert len(ephemeral_pubkey) == 33
         nonce = self.getScriptLockTxNonce(vkbv)
-        p2wsh_addr = self.encode_p2wsh(getP2WSH(script))
+        p2wsh_addr = self.encode_p2wsh(self.getP2WSHScriptDest(script))
         inputs = []
         outputs = [
             {
@@ -330,7 +328,7 @@ class PARTInterfaceBlind(PARTInterface):
         locked_coin = input_blinded_info["amount"]
         tx_lock_id = lock_tx_obj["txid"]
         refund_script = self.genScriptLockRefundTxScript(Kal, Kaf, csv_val)
-        p2wsh_addr = self.encode_p2wsh(getP2WSH(refund_script))
+        p2wsh_addr = self.encode_p2wsh(self.getP2WSHScriptDest(refund_script))
 
         inputs = [
             {
@@ -495,7 +493,7 @@ class PARTInterfaceBlind(PARTInterface):
         lock_txo_scriptpk = bytes.fromhex(
             lock_tx_obj["vout"][lock_output_n]["scriptPubKey"]["hex"]
         )
-        script_pk = CScript([OP_0, hashlib.sha256(script_out).digest()])
+        script_pk = self.getP2WSHScriptDest(script_out)
         ensure(lock_txo_scriptpk == script_pk, "Bad output script")
         A, B = extractScriptLockScriptValues(script_out)
         ensure(A == Kal, "Bad script leader pubkey")
@@ -572,7 +570,7 @@ class PARTInterfaceBlind(PARTInterface):
         lock_refund_txo_scriptpk = bytes.fromhex(
             lock_refund_tx_obj["vout"][lock_refund_output_n]["scriptPubKey"]["hex"]
         )
-        script_pk = CScript([OP_0, hashlib.sha256(script_out).digest()])
+        script_pk = self.getP2WSHScriptDest(script_out)
         ensure(lock_refund_txo_scriptpk == script_pk, "Bad output script")
         A, B, csv_val, C = extractScriptLockRefundScriptValues(script_out)
         ensure(A == Kal, "Bad script pubkey")
diff --git a/basicswap/util/script.py b/basicswap/util/script.py
index 996ceed..1ceaa78 100644
--- a/basicswap/util/script.py
+++ b/basicswap/util/script.py
@@ -1,11 +1,11 @@
 # -*- coding: utf-8 -*-
 
 # Copyright (c) 2022 tecnovert
+# Copyright (c) 2025 The Basicswap developers
 # Distributed under the MIT software license, see the accompanying
 # file LICENSE or http://www.opensource.org/licenses/mit-license.php.
 
 import struct
-import hashlib
 from basicswap.contrib.test_framework.script import (
     OP_PUSHDATA1,
     OP_PUSHDATA2,
@@ -89,14 +89,6 @@ def decodePushData(script_bytes, o):
     return (data, i + datasize - o)
 
 
-def getP2SHScriptForHash(p2sh):
-    return bytes((OpCodes.OP_HASH160, 0x14)) + p2sh + bytes((OpCodes.OP_EQUAL,))
-
-
-def getP2WSH(script):
-    return bytes((OpCodes.OP_0, 0x20)) + hashlib.sha256(script).digest()
-
-
 def SerialiseNumCompact(v):
     if v < 253:
         return bytes((v,))