test: add script_util helper for creating bare multisig scripts

test/functional/test_framework/blocktools.py

@@ -32,13 +32,13 @@ from .script import (
     CScriptNum,
     CScriptOp,
     OP_1,
-    OP_CHECKMULTISIG,
     OP_RETURN,
     OP_TRUE,
 )
 from .script_util import (
     key_to_p2pk_script,
     key_to_p2wpkh_script,
+    keys_to_multisig_script,
     script_to_p2wsh_script,
 )
 from .util import assert_equal
@@ -209,7 +209,7 @@ def witness_script(use_p2wsh, pubkey):
         pkscript = key_to_p2wpkh_script(pubkey)
     else:
         # 1-of-1 multisig
-        witness_script = CScript([OP_1, bytes.fromhex(pubkey), OP_1, OP_CHECKMULTISIG])
+        witness_script = keys_to_multisig_script([pubkey])
         pkscript = script_to_p2wsh_script(witness_script)
     return pkscript.hex()
 
@@ -218,7 +218,7 @@ def create_witness_tx(node, use_p2wsh, utxo, pubkey, encode_p2sh, amount):
 
     Optionally wrap the segwit output using P2SH."""
     if use_p2wsh:
-        program = CScript([OP_1, bytes.fromhex(pubkey), OP_1, OP_CHECKMULTISIG])
+        program = keys_to_multisig_script([pubkey])
         addr = script_to_p2sh_p2wsh(program) if encode_p2sh else script_to_p2wsh(program)
     else:
         addr = key_to_p2sh_p2wpkh(pubkey) if encode_p2sh else key_to_p2wpkh(pubkey)

test/functional/test_framework/script_util.py

@@ -5,7 +5,9 @@
 """Useful Script constants and utils."""
 from test_framework.script import (
     CScript,
+    CScriptOp,
     OP_0,
+    OP_CHECKMULTISIG,
     OP_CHECKSIG,
     OP_DUP,
     OP_EQUAL,
@@ -41,6 +43,17 @@ def key_to_p2pk_script(key):
     return CScript([key, OP_CHECKSIG])
 
 
+def keys_to_multisig_script(keys, *, k=None):
+    n = len(keys)
+    if k is None:  # n-of-n multisig by default
+        k = n
+    assert k <= n
+    op_k = CScriptOp.encode_op_n(k)
+    op_n = CScriptOp.encode_op_n(n)
+    checked_keys = [check_key(key) for key in keys]
+    return CScript([op_k] + checked_keys + [op_n, OP_CHECKMULTISIG])
+
+
 def keyhash_to_p2pkh_script(hash):
     assert len(hash) == 20
     return CScript([OP_DUP, OP_HASH160, hash, OP_EQUALVERIFY, OP_CHECKSIG])

test/functional/test_framework/wallet_util.py

@@ -15,15 +15,10 @@ from test_framework.address import (
     script_to_p2wsh,
 )
 from test_framework.key import ECKey
-from test_framework.script import (
-    CScript,
-    OP_2,
-    OP_3,
-    OP_CHECKMULTISIG,
-)
 from test_framework.script_util import (
     key_to_p2pkh_script,
     key_to_p2wpkh_script,
+    keys_to_multisig_script,
     script_to_p2sh_script,
     script_to_p2wsh_script,
 )
@@ -92,7 +87,7 @@ def get_multisig(node):
         addr = node.getaddressinfo(node.getnewaddress())
         addrs.append(addr['address'])
         pubkeys.append(addr['pubkey'])
-    script_code = CScript([OP_2] + [bytes.fromhex(pubkey) for pubkey in pubkeys] + [OP_3, OP_CHECKMULTISIG])
+    script_code = keys_to_multisig_script(pubkeys, k=2)
     witness_script = script_to_p2wsh_script(script_code)
     return Multisig(privkeys=[node.dumpprivkey(addr) for addr in addrs],
                     pubkeys=pubkeys,