Merge #2747: QA: Add proper bech32 encoding/decoding utilities to pyt…

…hon framework

7e04420 QA: Add proper bech32 encoding/decoding utilities to python framework (random-zebra)

Pull request description:

  As per title, completes the rudimentary python implementation introduced in #2733

ACKs for top commit:
  furszy:
    you had some fun here, utACK 7e04420

Tree-SHA512: b32c126efa44dedde32c473b3c2a25cac21c3380d881637bdb87764bae0928b8fb53701b75ef72ab1e1d8da32af0d8f367428571813c33340550678ff3ca0c5d

test/functional/p2p_quorum_connect.py

@@ -8,14 +8,14 @@
 
 from random import getrandbits
 from test_framework.test_framework import PivxDMNTestFramework
+from test_framework.bech32 import bech32_str_to_bytes
 from test_framework.mininode import P2PInterface
 from test_framework.messages import msg_version
 from test_framework.util import (
     assert_equal,
     bytes_to_hex_str,
     connect_nodes,
     hash256,
-    bech32_str_to_bytes,
     wait_until,
 )
 

test/functional/test_framework/bech32.py

@@ -0,0 +1,113 @@
+#!/usr/bin/env python3
+# Copyright (c) 2017 Pieter Wuille
+# Copyright (c) 2022 The PIVX developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Reference implementation for Bech32 encoding/decoding"""
+
+CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
+BECH32_CONST = 1
+
+def bech32_polymod(values):
+    """Internal function that computes the Bech32 checksum."""
+    generator = [0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3]
+    chk = 1
+    for value in values:
+        top = chk >> 25
+        chk = (chk & 0x1ffffff) << 5 ^ value
+        for i in range(5):
+            chk ^= generator[i] if ((top >> i) & 1) else 0
+    return chk
+
+def bech32_hrp_expand(hrp):
+    """Expand the HRP into values for checksum computation."""
+    return [ord(x) >> 5 for x in hrp] + [0] + [ord(x) & 31 for x in hrp]
+
+def bech32_verify_checksum(hrp, data):
+    """Verify a checksum given HRP and converted data characters."""
+    return bech32_polymod(bech32_hrp_expand(hrp) + data) == BECH32_CONST
+
+def bech32_create_checksum(hrp, data):
+    """Compute the checksum values given HRP and data."""
+    values = bech32_hrp_expand(hrp) + data
+    polymod = bech32_polymod(values + [0, 0, 0, 0, 0, 0]) ^ BECH32_CONST
+    return [(polymod >> 5 * (5 - i)) & 31 for i in range(6)]
+
+def bech32_encode(hrp, data):
+    """Compute a Bech32 string given HRP and data values."""
+    combined = data + bech32_create_checksum(hrp, data)
+    return hrp + '1' + ''.join([CHARSET[d] for d in combined])
+
+def bech32_decode(bech):
+    """Validate a Bech32 string, and determine HRP and data."""
+    if ((any(ord(x) < 33 or ord(x) > 126 for x in bech)) or
+            (bech.lower() != bech and bech.upper() != bech)):
+        return None, None
+    bech = bech.lower()
+    pos = bech.rfind('1')
+    if pos < 1 or pos + 7 > len(bech) or len(bech) > 95:
+        return None, None
+    if not all(x in CHARSET for x in bech[pos+1:]):
+        return None, None
+    hrp = bech[:pos]
+    data = [CHARSET.find(x) for x in bech[pos+1:]]
+    if not bech32_verify_checksum(hrp, data):
+        return None, None
+    return hrp, data[:-6]
+
+def convertbits(data, frombits, tobits, pad=True):
+    """General power-of-2 base conversion."""
+    acc = 0
+    bits = 0
+    ret = []
+    maxv = (1 << tobits) - 1
+    max_acc = (1 << (frombits + tobits - 1)) - 1
+    for value in data:
+        if value < 0 or (value >> frombits):
+            return None
+        acc = ((acc << frombits) | value) & max_acc
+        bits += frombits
+        while bits >= tobits:
+            bits -= tobits
+            ret.append((acc >> bits) & maxv)
+    if pad:
+        if bits:
+            ret.append((acc << (tobits - bits)) & maxv)
+    elif bits >= frombits or ((acc << (tobits - bits)) & maxv):
+        return None
+    return ret
+
+def bech32_str_to_bytes(bech_str):
+    _, data = bech32_decode(bech_str)
+    if data is None:
+        return None
+    decoded = convertbits(data, 5, 8, False)
+    if decoded is None:
+        return None
+    return bytes(decoded)
+
+
+
+if __name__ == '__main__':
+    def test_bls_bech32(bech32_str, hrp, bytes_data):
+        # test Bech32 encoding/decoding for BLS secret keys
+        h, d = bech32_decode(bech32_str)
+        assert h == hrp
+        assert bech32_str == bech32_encode(h, d)
+        assert bech32_str_to_bytes(bech32_str) == bytes_data
+        assert bech32_decode(bech32_str + CHARSET[0]) == (None, None)   # add 1 char
+        assert bech32_decode(bech32_str[:-1]) == (None, None)           # remove 1 char
+        bech32_str = bech32_str[:-1] + CHARSET[(CHARSET.index(bech32_str[-1]) + 1) % len(CHARSET)]
+        assert bech32_decode(bech32_str) == (None, None)                # change 1 char
+
+    # BLS secret key
+    sk_bls = "bls-sk-test1y8z22ksxta8hwqh9r6jsyc42frqft43t2uav6s0vqrjjf67metnq2mwkm0"
+    sk = b'!\xc4\xa5Z\x06_Ow\x02\xe5\x1e\xa5\x02b\xaaH\xc0\x95\xd6+W:\xcdA\xec\x00\xe5$\xeb\xdb\xca\xe6'
+    test_bls_bech32(sk_bls, "bls-sk-test", sk)
+
+    # BLS public key
+    pk_bls = "bls-pk-test132ngslan8s5ha4k74wynyez3drzkw3fa2d60676ch3ac6gzx6ttd0xg8pqj0x5n5tgajvuycqmgtgnsep90"
+    pk = b'\x8a\xa6\x88\x7f\xb3<)~\xd6\xde\xab\x892dQh\xc5gE=St\xfd{X\xbc{\x8d F\xd2\xd6\xd7\x99\x07\x08$\xf3RtZ;&p\x98\x06\xd0\xb4'
+    test_bls_bech32(pk_bls, "bls-pk-test", pk)
+
+    print("All good.")

test/functional/test_framework/util.py

@@ -201,43 +201,6 @@ def hash256(byte_str):
 def hex_str_to_bytes(hex_str):
     return unhexlify(hex_str.encode('ascii'))
 
-def convertbits(data, frombits, tobits, pad=True):
-    """General power-of-2 base conversion."""
-    acc = 0
-    bits = 0
-    ret = []
-    maxv = (1 << tobits) - 1
-    max_acc = (1 << (frombits + tobits - 1)) - 1
-    for value in data:
-        if value < 0 or (value >> frombits):
-            return None
-        acc = ((acc << frombits) | value) & max_acc
-        bits += frombits
-        while bits >= tobits:
-            bits -= tobits
-            ret.append((acc >> bits) & maxv)
-    if pad:
-        if bits:
-            ret.append((acc << (tobits - bits)) & maxv)
-    elif bits >= frombits or ((acc << (tobits - bits)) & maxv):
-        return None
-    return ret
-
-def bech32_str_to_bytes(bech_str):
-    BECH32_CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
-    bech_str = bech_str.lower()
-    pos = bech_str.rfind('1')
-    if pos < 1 or pos + 7 > len(bech_str):
-        return None
-    if not all(x in BECH32_CHARSET for x in bech_str[pos+1:]):
-        return None
-    # !TODO: verify checksum
-    data = [BECH32_CHARSET.find(x) for x in bech_str[pos+1:]]
-    decoded = convertbits(data[:-6], 5, 8, False)
-    if decoded is None:
-        return None
-    return bytes(decoded)
-
 def str_to_b64str(string):
     return b64encode(string.encode('utf-8')).decode('ascii')