diff options
| author | Determinant <[email protected]> | 2021-01-11 14:20:43 -0500 |
|---|---|---|
| committer | Determinant <[email protected]> | 2021-01-11 14:20:43 -0500 |
| commit | e5b01bb04331676cbc5e202993e4bf883cb97633 (patch) | |
| tree | 2882b010ca13746aa58e23265d15f0c4e1ddc5a2 /frozen_deps/base58/__init__.py | |
| parent | aa9206a264b43f5d538fc39c2c1532d279e6f775 (diff) | |
upgrade to Python 3.9
Diffstat (limited to 'frozen_deps/base58/__init__.py')
| -rw-r--r-- | frozen_deps/base58/__init__.py | 65 |
1 files changed, 47 insertions, 18 deletions
diff --git a/frozen_deps/base58/__init__.py b/frozen_deps/base58/__init__.py index ff2fa18..a86ceb7 100644 --- a/frozen_deps/base58/__init__.py +++ b/frozen_deps/base58/__init__.py @@ -9,15 +9,17 @@ with the bitcoin network. # forum post by Gavin Andresen, so direct your praise to him. # This module adds shiny packaging and support for python3. +from functools import lru_cache from hashlib import sha256 -from typing import Union +from typing import Mapping, Union -__version__ = '2.0.1' +__version__ = '2.1.0' # 58 character alphabet used BITCOIN_ALPHABET = \ b'123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz' RIPPLE_ALPHABET = b'rpshnaf39wBUDNEGHJKLM4PQRST7VWXYZ2bcdeCg65jkm8oFqi1tuvAxyz' +XRP_ALPHABET = RIPPLE_ALPHABET # Retro compatibility alphabet = BITCOIN_ALPHABET @@ -39,8 +41,9 @@ def b58encode_int( if not i and default_one: return alphabet[0:1] string = b"" + base = len(alphabet) while i: - i, idx = divmod(i, 58) + i, idx = divmod(i, base) string = alphabet[idx:idx+1] + string return string @@ -53,35 +56,60 @@ def b58encode( """ v = scrub_input(v) - nPad = len(v) + origlen = len(v) v = v.lstrip(b'\0') - nPad -= len(v) + newlen = len(v) + + acc = int.from_bytes(v, byteorder='big') # first byte is most significant - p, acc = 1, 0 - for c in reversed(v): - acc += p * c - p = p << 8 result = b58encode_int(acc, default_one=False, alphabet=alphabet) - return alphabet[0:1] * nPad + result + return alphabet[0:1] * (origlen - newlen) + result + + +@lru_cache() +def _get_base58_decode_map(alphabet: bytes, + autofix: bool) -> Mapping[int, int]: + invmap = {char: index for index, char in enumerate(alphabet)} + + if autofix: + groups = [b'0Oo', b'Il1'] + for group in groups: + pivots = [c for c in group if c in invmap] + if len(pivots) == 1: + for alternative in group: + invmap[alternative] = invmap[pivots[0]] + + return invmap def b58decode_int( - v: Union[str, bytes], alphabet: bytes = BITCOIN_ALPHABET + v: Union[str, bytes], alphabet: bytes = BITCOIN_ALPHABET, *, + autofix: bool = False ) -> int: """ Decode a Base58 encoded string as an integer """ - v = v.rstrip() + if b' ' not in alphabet: + v = v.rstrip() v = scrub_input(v) + map = _get_base58_decode_map(alphabet, autofix=autofix) + decimal = 0 - for char in v: - decimal = decimal * 58 + alphabet.index(char) + base = len(alphabet) + try: + for char in v: + decimal = decimal * base + map[char] + except KeyError as e: + raise ValueError( + "Invalid character <{char}>".format(char=chr(e.args[0])) + ) from None return decimal def b58decode( - v: Union[str, bytes], alphabet: bytes = BITCOIN_ALPHABET + v: Union[str, bytes], alphabet: bytes = BITCOIN_ALPHABET, *, + autofix: bool = False ) -> bytes: """ Decode a Base58 encoded string @@ -93,7 +121,7 @@ def b58decode( v = v.lstrip(alphabet[0:1]) newlen = len(v) - acc = b58decode_int(v, alphabet=alphabet) + acc = b58decode_int(v, alphabet=alphabet, autofix=autofix) result = [] while acc > 0: @@ -116,11 +144,12 @@ def b58encode_check( def b58decode_check( - v: Union[str, bytes], alphabet: bytes = BITCOIN_ALPHABET + v: Union[str, bytes], alphabet: bytes = BITCOIN_ALPHABET, *, + autofix: bool = False ) -> bytes: '''Decode and verify the checksum of a Base58 encoded string''' - result = b58decode(v, alphabet=alphabet) + result = b58decode(v, alphabet=alphabet, autofix=autofix) result, check = result[:-4], result[-4:] digest = sha256(sha256(result).digest()).digest() |