git / moonbite-core / test/functional/test_framework/segwit_addr.py · raw

#!/usr/bin/env python3# Copyright (c) 2017 Pieter Wuille# Distributed under the MIT software license, see the accompanying# file COPYING or http://www.opensource.org/licenses/mit-license.php."""Reference implementation for Bech32/Bech32m and segwit addresses."""import unittestfrom enum import EnumCHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"BECH32_CONST = 1BECH32M_CONST = 0x2bc830a3class Encoding(Enum):    """Enumeration type to list the various supported encodings."""    BECH32 = 1    BECH32M = 2def 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 chkdef 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."""    check = bech32_polymod(bech32_hrp_expand(hrp) + data)    if check == BECH32_CONST:        return Encoding.BECH32    elif check == BECH32M_CONST:        return Encoding.BECH32M    else:        return Nonedef bech32_create_checksum(encoding, hrp, data):    """Compute the checksum values given HRP and data."""    values = bech32_hrp_expand(hrp) + data    const = BECH32M_CONST if encoding == Encoding.BECH32M else BECH32_CONST    polymod = bech32_polymod(values + [0, 0, 0, 0, 0, 0]) ^ const    return [(polymod >> 5 * (5 - i)) & 31 for i in range(6)]def bech32_encode(encoding, hrp, data):    """Compute a Bech32 or Bech32m string given HRP and data values."""    combined = data + bech32_create_checksum(encoding, hrp, data)    return hrp + '1' + ''.join([CHARSET[d] for d in combined])def bech32_decode(bech):    """Validate a Bech32/Bech32m 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, None)    bech = bech.lower()    pos = bech.rfind('1')    if pos < 1 or pos + 7 > len(bech) or len(bech) > 90:        return (None, None, None)    if not all(x in CHARSET for x in bech[pos+1:]):        return (None, None, None)    hrp = bech[:pos]    data = [CHARSET.find(x) for x in bech[pos+1:]]    encoding = bech32_verify_checksum(hrp, data)    if encoding is None:        return (None, None, None)    return (encoding, 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 retdef decode_segwit_address(hrp, addr):    """Decode a segwit address."""    encoding, hrpgot, data = bech32_decode(addr)    if hrpgot != hrp:        return (None, None)    decoded = convertbits(data[1:], 5, 8, False)    if decoded is None or len(decoded) < 2 or len(decoded) > 40:        return (None, None)    if data[0] > 16:        return (None, None)    if data[0] == 0 and len(decoded) != 20 and len(decoded) != 32:        return (None, None)    if (data[0] == 0 and encoding != Encoding.BECH32) or (data[0] != 0 and encoding != Encoding.BECH32M):        return (None, None)    return (data[0], decoded)def encode_segwit_address(hrp, witver, witprog):    """Encode a segwit address."""    encoding = Encoding.BECH32 if witver == 0 else Encoding.BECH32M    ret = bech32_encode(encoding, hrp, [witver] + convertbits(witprog, 8, 5))    if decode_segwit_address(hrp, ret) == (None, None):        return None    return retclass TestFrameworkScript(unittest.TestCase):    def test_segwit_encode_decode(self):        def test_python_bech32(addr):            hrp = addr[:4]            self.assertEqual(hrp, "bcrt")            (witver, witprog) = decode_segwit_address(hrp, addr)            self.assertEqual(encode_segwit_address(hrp, witver, witprog), addr)        # P2WPKH        test_python_bech32('bcrt1qthmht0k2qnh3wy7336z05lu2km7emzfpm3wg46')        # P2WSH        test_python_bech32('bcrt1qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq3xueyj')        test_python_bech32('bcrt1qft5p2uhsdcdc3l2ua4ap5qqfg4pjaqlp250x7us7a8qqhrxrxfsqseac85')        # P2TR        test_python_bech32('bcrt1p0xlxvlhemja6c4dqv22uapctqupfhlxm9h8z3k2e72q4k9hcz7vqc8gma6')