From 33a99a1a17a569493cbf009bcd5458939c153f54 Mon Sep 17 00:00:00 2001 From: josibake Date: Mon, 15 Jan 2024 12:05:08 +0100 Subject: Add reference.py with test vectors * reference.py contains the silent payment specific code * secp256k1.py for doing the EC operations * bech32m.py contains code for encoding/decoding bech32(m) addresses * bitcoin_utils.py contains some helper code, not specific to silent payments * send_and_receive_test_vectors.json contains the wallet unit test vectors Co-Authored-By: S3RK <1466284+S3RK@users.noreply.github.com> Co-Authored-By: Oghenovo Usiwoma <37949128+Eunovo@users.noreply.github.com> Co-authored-by: S.Blagogee <34041358+setavenger@users.noreply.github.com> --- bip-0352/bech32m.py | 135 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 135 insertions(+) create mode 100644 bip-0352/bech32m.py (limited to 'bip-0352/bech32m.py') diff --git a/bip-0352/bech32m.py b/bip-0352/bech32m.py new file mode 100644 index 0000000..795e153 --- /dev/null +++ b/bip-0352/bech32m.py @@ -0,0 +1,135 @@ +# Copyright (c) 2017, 2020 Pieter Wuille +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +# THE SOFTWARE. + +"""Reference implementation for Bech32/Bech32m and segwit addresses.""" + + +from enum import Enum + +class Encoding(Enum): + """Enumeration type to list the various supported encodings.""" + BECH32 = 1 + BECH32M = 2 + +CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l" +BECH32M_CONST = 0x2bc830a3 + +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.""" + const = bech32_polymod(bech32_hrp_expand(hrp) + data) + if const == 1: + return Encoding.BECH32 + if const == BECH32M_CONST: + return Encoding.BECH32M + return None + +def bech32_create_checksum(hrp, data, spec): + """Compute the checksum values given HRP and data.""" + values = bech32_hrp_expand(hrp) + data + const = BECH32M_CONST if spec == Encoding.BECH32M else 1 + 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(hrp, data, spec): + """Compute a Bech32 string given HRP and data values.""" + combined = data + bech32_create_checksum(hrp, data, spec) + 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') + + # remove the requirement that bech32m be less than 90 chars + if pos < 1 or pos + 7 > len(bech): + 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:]] + spec = bech32_verify_checksum(hrp, data) + if spec is None: + return (None, None, None) + return (hrp, data[:-6], spec) + +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, spec = bech32_decode(addr) + if hrpgot != hrp: + return (None, None) + decoded = convertbits(data[1:], 5, 8, False) + if decoded is None or len(decoded) < 2: + return (None, None) + if data[0] > 16: + return (None, None) + return (data[0], decoded) + + +def encode(hrp, witver, witprog): + """Encode a segwit address.""" + spec = Encoding.BECH32 if witver == 0 else Encoding.BECH32M + ret = bech32_encode(hrp, [witver] + convertbits(witprog, 8, 5), spec) + if decode(hrp, ret) == (None, None): + return None + return ret -- cgit v1.2.3