test: test_bech32_decode in address.py

Adds bech32_to_bytes() which can decode a bech32 address and return the
version as an `int` and the payload in bytes.

bech32_to_bytes() is used by the test_bech32_decode unit test to test
decoding of segwit addresses.

Author: ismaelsadeeq

test/functional/test_framework/address.py

@@ -20,8 +20,11 @@
     sha256,
     taproot_construct,
 )
-from .segwit_addr import encode_segwit_address
 from .util import assert_equal
+from test_framework.segwit_addr import (
+    decode_segwit_address,
+    encode_segwit_address,
+)
 
 ADDRESS_BCRT1_UNSPENDABLE = 'bcrt1qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq3xueyj'
 ADDRESS_BCRT1_UNSPENDABLE_DESCRIPTOR = 'addr(bcrt1qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq3xueyj)#juyq9d97'
@@ -159,6 +162,16 @@ def check_script(script):
     assert False
 
 
+def bech32_to_bytes(address):
+    hrp = address.split('1')[0]
+    if hrp not in ['bc', 'tb', 'bcrt']:
+        return (None, None)
+    version, payload = decode_segwit_address(hrp, address)
+    if version is None:
+        return (None, None)
+    return version, bytearray(payload)
+
+
 class TestFrameworkScript(unittest.TestCase):
     def test_base58encodedecode(self):
         def check_base58(data, version):
@@ -176,3 +189,18 @@ def check_base58(data, version):
         check_base58(bytes.fromhex('0041c1eaf111802559bad61b60d62b1f897c63928a'), 0)
         check_base58(bytes.fromhex('000041c1eaf111802559bad61b60d62b1f897c63928a'), 0)
         check_base58(bytes.fromhex('00000041c1eaf111802559bad61b60d62b1f897c63928a'), 0)
+
+
+    def test_bech32_decode(self):
+        def check_bech32_decode(payload, version):
+            hrp = "tb"
+            self.assertEqual(bech32_to_bytes(encode_segwit_address(hrp, version, payload)), (version, payload))
+
+        check_bech32_decode(bytes.fromhex('36e3e2a33f328de12e4b43c515a75fba2632ecc3'), 0)
+        check_bech32_decode(bytes.fromhex('823e9790fc1d1782321140d4f4aa61aabd5e045b'), 0)
+        check_bech32_decode(bytes.fromhex('79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798'), 1)
+        check_bech32_decode(bytes.fromhex('39cf8ebd95134f431c39db0220770bd127f5dd3cc103c988b7dcd577ae34e354'), 1)
+        check_bech32_decode(bytes.fromhex('708244006d27c757f6f1fc6f853b6ec26268b727866f7ce632886e34eb5839a3'), 1)
+        check_bech32_decode(bytes.fromhex('616211ab00dffe0adcb6ce258d6d3fd8cbd901e2'), 0)
+        check_bech32_decode(bytes.fromhex('b6a7c98b482d7fb21c9fa8e65692a0890410ff22'), 0)
+        check_bech32_decode(bytes.fromhex('f0c2109cb1008cfa7b5a09cc56f7267cd8e50929'), 0)