You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
106 lines
2.9 KiB
106 lines
2.9 KiB
# Copyright (c) 2012-2016 The Bitcoin Core developers |
|
# Distributed under the MIT software license, see the accompanying |
|
# file COPYING or http://www.opensource.org/licenses/mit-license.php. |
|
''' |
|
Bitcoin base58 encoding and decoding. |
|
|
|
Based on https://bitcointalk.org/index.php?topic=1026.0 (public domain) |
|
''' |
|
import hashlib |
|
|
|
# for compatibility with following code... |
|
class SHA256: |
|
new = hashlib.sha256 |
|
|
|
if str != bytes: |
|
# Python 3.x |
|
def ord(c): |
|
return c |
|
def chr(n): |
|
return bytes( (n,) ) |
|
|
|
__b58chars = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz' |
|
__b58base = len(__b58chars) |
|
b58chars = __b58chars |
|
|
|
def b58encode(v): |
|
""" encode v, which is a string of bytes, to base58. |
|
""" |
|
long_value = 0 |
|
for (i, c) in enumerate(v[::-1]): |
|
long_value += (256**i) * ord(c) |
|
|
|
result = '' |
|
while long_value >= __b58base: |
|
div, mod = divmod(long_value, __b58base) |
|
result = __b58chars[mod] + result |
|
long_value = div |
|
result = __b58chars[long_value] + result |
|
|
|
# Bitcoin does a little leading-zero-compression: |
|
# leading 0-bytes in the input become leading-1s |
|
nPad = 0 |
|
for c in v: |
|
if c == '\0': nPad += 1 |
|
else: break |
|
|
|
return (__b58chars[0]*nPad) + result |
|
|
|
def b58decode(v, length = None): |
|
""" decode v into a string of len bytes |
|
""" |
|
long_value = 0 |
|
for (i, c) in enumerate(v[::-1]): |
|
long_value += __b58chars.find(c) * (__b58base**i) |
|
|
|
result = bytes() |
|
while long_value >= 256: |
|
div, mod = divmod(long_value, 256) |
|
result = chr(mod) + result |
|
long_value = div |
|
result = chr(long_value) + result |
|
|
|
nPad = 0 |
|
for c in v: |
|
if c == __b58chars[0]: nPad += 1 |
|
else: break |
|
|
|
result = chr(0)*nPad + result |
|
if length is not None and len(result) != length: |
|
return None |
|
|
|
return result |
|
|
|
def checksum(v): |
|
"""Return 32-bit checksum based on SHA256""" |
|
return SHA256.new(SHA256.new(v).digest()).digest()[0:4] |
|
|
|
def b58encode_chk(v): |
|
"""b58encode a string, with 32-bit checksum""" |
|
return b58encode(v + checksum(v)) |
|
|
|
def b58decode_chk(v): |
|
"""decode a base58 string, check and remove checksum""" |
|
result = b58decode(v) |
|
if result is None: |
|
return None |
|
if result[-4:] == checksum(result[:-4]): |
|
return result[:-4] |
|
else: |
|
return None |
|
|
|
def get_bcaddress_version(strAddress): |
|
""" Returns None if strAddress is invalid. Otherwise returns integer version of address. """ |
|
addr = b58decode_chk(strAddress) |
|
if addr is None or len(addr)!=21: return None |
|
version = addr[0] |
|
return ord(version) |
|
|
|
if __name__ == '__main__': |
|
# Test case (from http://gitorious.org/bitcoin/python-base58.git) |
|
assert get_bcaddress_version('15VjRaDX9zpbA8LVnbrCAFzrVzN7ixHNsC') is 0 |
|
_ohai = 'o hai'.encode('ascii') |
|
_tmp = b58encode(_ohai) |
|
assert _tmp == 'DYB3oMS' |
|
assert b58decode(_tmp, 5) == _ohai |
|
print("Tests passed")
|
|
|