diff --git a/test/functional/test_framework/liquid_addr.py b/test/functional/test_framework/liquid_addr.py new file mode 100644 index 0000000000..c8ae77275b --- /dev/null +++ b/test/functional/test_framework/liquid_addr.py @@ -0,0 +1,106 @@ +#!/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 Blech32 and segwit addresses.""" + + +CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l" + +def blech32_polymod(values): + """Internal function that computes the blech32 checksum.""" + generator = [0x7d52fba40bd886, 0x5e8dbf1a03950c, 0x1c3a3c74072a18, 0x385d72fa0e5139, 0x7093e5a608865b] # new generators, 7 bytes + chk = 1 + for value in values: + top = chk >> 55 # 25->55 + chk = ((chk & 0x7fffffffffffff) << 5) ^^ value # 0x1ffffff->0x7fffffffffffff + for i in range(5): + chk ^= generator[i] if ((top >> i) & 1) else 0 + return chk + + +def blech32_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 blech32_verify_checksum(hrp, data): + """Verify a checksum given HRP and converted data characters.""" + return blech32_polymod(blech32_hrp_expand(hrp) + data) == 1 + + +def blech32_create_checksum(hrp, data): + """Compute the checksum values given HRP and data.""" + values = blech32_hrp_expand(hrp) + data + polymod = blech32_polymod(values + [0]*12) ^^ 1 # 6->12 + return [(polymod >> 5 * (11 - i)) & 31 for i in range(12)] +# ^ 5 ^ 6 + +def blech32_encode(hrp, data): + """Compute a blech32 string given HRP and data values.""" + combined = data + blech32_create_checksum(hrp, data) + return hrp + '1' + ''.join([CHARSET[d] for d in combined]) + + +def blech32_decode(bech): + """Validate a blech32 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 + 13 > len(bech) or len(bech) > 1000: # 7->13 90->1000 + 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 blech32_verify_checksum(hrp, data): + return (None, None) + return (hrp, data[:-12]) # 6->12 + + +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 decode(hrp, addr): + """Decode a segwit address.""" + hrpgot, data = blech32_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) + return (data[0], decoded) + + +def encode(hrp, witver, witprog): + """Encode a segwit address.""" + ret = blech32_encode(hrp, [witver] + convertbits(witprog, 8, 5)) + if decode(hrp, ret) == (None, None): + return None + return ret