From c98c53f20cadeda53f6a9323f72363593d174f68 Mon Sep 17 00:00:00 2001
From: Pieter Wuille <pieter@wuille.net>
Date: Wed, 27 Oct 2021 15:07:35 -0400
Subject: [PATCH] tests: abstract out precomputed BIP341 signature hash
 elements

---
 test/functional/test_framework/script.py | 25 +++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/test/functional/test_framework/script.py b/test/functional/test_framework/script.py
index 46c723b06ab..de71e19251c 100644
--- a/test/functional/test_framework/script.py
+++ b/test/functional/test_framework/script.py
@@ -755,6 +755,21 @@ class TestFrameworkScript(unittest.TestCase):
         for value in values:
             self.assertEqual(CScriptNum.decode(CScriptNum.encode(CScriptNum(value))), value)
 
+def BIP341_sha_prevouts(txTo):
+    return sha256(b"".join(i.prevout.serialize() for i in txTo.vin))
+
+def BIP341_sha_amounts(spent_utxos):
+    return sha256(b"".join(struct.pack("<q", u.nValue) for u in spent_utxos))
+
+def BIP341_sha_scriptpubkeys(spent_utxos):
+    return sha256(b"".join(ser_string(u.scriptPubKey) for u in spent_utxos))
+
+def BIP341_sha_sequences(txTo):
+    return sha256(b"".join(struct.pack("<I", i.nSequence) for i in txTo.vin))
+
+def BIP341_sha_outputs(txTo):
+    return sha256(b"".join(o.serialize() for o in txTo.vout))
+
 def TaprootSignatureMsg(txTo, spent_utxos, hash_type, input_index = 0, scriptpath = False, script = CScript(), codeseparator_pos = -1, annex = None, leaf_ver = LEAF_VERSION_TAPSCRIPT):
     assert (len(txTo.vin) == len(spent_utxos))
     assert (input_index < len(txTo.vin))
@@ -765,12 +780,12 @@ def TaprootSignatureMsg(txTo, spent_utxos, hash_type, input_index = 0, scriptpat
     ss += struct.pack("<i", txTo.nVersion)
     ss += struct.pack("<I", txTo.nLockTime)
     if in_type != SIGHASH_ANYONECANPAY:
-        ss += sha256(b"".join(i.prevout.serialize() for i in txTo.vin))
-        ss += sha256(b"".join(struct.pack("<q", u.nValue) for u in spent_utxos))
-        ss += sha256(b"".join(ser_string(u.scriptPubKey) for u in spent_utxos))
-        ss += sha256(b"".join(struct.pack("<I", i.nSequence) for i in txTo.vin))
+        ss += BIP341_sha_prevouts(txTo)
+        ss += BIP341_sha_amounts(spent_utxos)
+        ss += BIP341_sha_scriptpubkeys(spent_utxos)
+        ss += BIP341_sha_sequences(txTo)
     if out_type == SIGHASH_ALL:
-        ss += sha256(b"".join(o.serialize() for o in txTo.vout))
+        ss += BIP341_sha_outputs(txTo)
     spend_type = 0
     if annex is not None:
         spend_type |= 1