WIP: fix p2sh redeemscript parsing (#124)

Co-authored-by: Michael Flaxman
Co-authored-by: Jimmy Song

Author: mflaxman

buidl/script.py

@@ -54,9 +54,13 @@ def __add__(self, other):
         return Script(self.commands + other.commands)
 
     @classmethod
-    def parse(cls, stream):
-        # get the length of the entire field
-        raw = read_varstr(stream)
+    def parse(cls, stream=None, raw=None):
+        if stream and raw:
+            raise ValueError("provide exactly one of stream/raw, not both")
+        if raw is None:
+            if stream is None:
+                raise ValueError("provide one of stream/raw")
+            raw = read_varstr(stream)
         length = len(raw)
         s = BytesIO(raw)
         # initialize the commands array
@@ -101,10 +105,16 @@ def parse(cls, stream):
                 commands.append(op_code)
         obj = cls(commands)
         if count != length:
+            # Would throw error, but Bitcoin Core will read the number of bytes that are there (not what was promised)
             print(f"mismatch between length and consumed bytes {count} vs {length}")
             obj.raw = raw
         return obj
 
+    @classmethod
+    def parse_hex(cls, hex_str):
+        """Helper method to make it easier to parse a hex string without converting to bytes"""
+        return cls.parse(raw=bytes.fromhex(hex_str))
+
     def raw_serialize(self):
         if self.raw:
             return self.raw

buidl/test/test_script.py

@@ -63,7 +63,7 @@ def test_address(self):
 
 
 class RedeemScriptTest(TestCase):
-    def test_redeem_script(self):
+    def test_nonstandard_redeemscript(self):
         hex_redeem_script = "4752210223136797cb0d7596cb5bd476102fe3aface2a06338e1afabffacf8c3cab4883c210385c865e61e275ba6fda4a3167180fc5a6b607150ff18797ee44737cd0d34507b52ae"
         stream = BytesIO(bytes.fromhex(hex_redeem_script))
         redeem_script = RedeemScript.parse(stream)
@@ -75,6 +75,24 @@ def test_redeem_script(self):
         self.assertEqual(redeem_script.address(network="testnet"), want)
         self.assertEqual(redeem_script.address(network="signet"), want)
 
+    def test_standard_redeemscript(self):
+        # This was tested against bitcoin core v0.22
+        # https://github.com/buidl-bitcoin/buidl-python/issues/123
+        redeem_script_hex = "522102be8d4de672b4d6149616962a7d193b702e608a1ed65aaa44f432ff9dd902252f21036ec4565fb304b0fc8e2cdd56e477816ab703e06d52f87279bf0cbdb9fa4941b221038fc14c8dd5a15828bd4fb0e206e443e3ac6e3e3782fbf6f0a1ff969a9ec8f28f53ae"
+        rs_obj = RedeemScript.parse_hex(redeem_script_hex)
+        self.assertEqual(
+            "2NAaGqgaZicBUXuA2iZc6ssxLEsS4sZwdwz", rs_obj.address("testnet")
+        )
+        self.assertEqual((2, 3), rs_obj.get_quorum())
+        self.assertTrue(rs_obj.is_p2sh_multisig())
+        pubkeys_wanted_hex = (
+            "02be8d4de672b4d6149616962a7d193b702e608a1ed65aaa44f432ff9dd902252f",
+            "036ec4565fb304b0fc8e2cdd56e477816ab703e06d52f87279bf0cbdb9fa4941b2",
+            "038fc14c8dd5a15828bd4fb0e206e443e3ac6e3e3782fbf6f0a1ff969a9ec8f28f",
+        )
+        for cnt, pubkey_bytes in enumerate(rs_obj.signing_pubkeys()):
+            self.assertEqual(pubkey_bytes.hex(), pubkeys_wanted_hex[cnt])
+
     def test_create_p2sh_multisig(self):
         BASE_PATH = "m/45h/0"
 

setup.py

@@ -6,7 +6,7 @@
 
 setup(
     name="buidl",
-    version="0.2.34",
+    version="0.2.35",
     author="Example Author",
     author_email="[email protected]",
     description="An easy-to-use and fully featured bitcoin library written in pure python (no dependencies).",