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# MoneroPy - A python toolbox for Monero
# Copyright (C) 2016 The MoneroPy Developers.
#
# MoneroPy is released under the BSD 3-Clause license. Use and redistribution of
# this software is subject to the license terms in the LICENSE file found in the
# top-level directory of this distribution.
__alphabet = [ord(s) for s in '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz']
__b58base = 58
__UINT64MAX = 2**64
__encodedBlockSizes = [0, 2, 3, 5, 6, 7, 9, 10, 11]
__fullBlockSize = 8
__fullEncodedBlockSize = 11
def _hexToBin(hex):
if len(hex) % 2 != 0:
return "Hex string has invalid length!"
return [int(hex[i*2:i*2+2], 16) for i in range(len(hex)//2)]
def _binToHex(bin):
return "".join([("0" + hex(int(bin[i])).split('x')[1])[-2:] for i in range(len(bin))])
def _strToBin(a):
return [ord(s) for s in a]
def _binToStr(bin):
return ''.join([chr(bin[i]) for i in range(len(bin))])
def _uint8be_to_64(data):
l_data = len(data)
if l_data < 1 or l_data > 8:
return "Invalid input length"
res = 0
switch = 9 - l_data
for i in range(l_data):
if switch == 1:
res = res << 8 | data[i]
elif switch == 2:
res = res << 8 | data[i]
elif switch == 3:
res = res << 8 | data[i]
elif switch == 4:
res = res << 8 | data[i]
elif switch == 5:
res = res << 8 | data[i]
elif switch == 6:
res = res << 8 | data[i]
elif switch == 7:
res = res << 8 | data[i]
elif switch == 8:
res = res << 8 | data[i]
else:
return "Impossible condition"
return res
def _uint64_to_8be(num, size):
res = [0] * size;
if size < 1 or size > 8:
return "Invalid input length"
twopow8 = 2**8
for i in range(size-1,-1,-1):
res[i] = num % twopow8
num = num // twopow8
return res
def encode_block(data, buf, index):
l_data = len(data)
if l_data < 1 or l_data > __fullEncodedBlockSize:
return "Invalid block length: " + str(l_data)
num = _uint8be_to_64(data)
i = __encodedBlockSizes[l_data] - 1
while num > 0:
remainder = num % __b58base
num = num // __b58base
buf[index+i] = __alphabet[remainder];
i -= 1
return buf
def encode(hex):
'''Encode hexadecimal string as base58 (ex: encoding a Monero address).'''
data = _hexToBin(hex)
l_data = len(data)
if l_data == 0:
return ""
full_block_count = l_data // __fullBlockSize
last_block_size = l_data % __fullBlockSize
res_size = full_block_count * __fullEncodedBlockSize + __encodedBlockSizes[last_block_size]
res = [0] * res_size
for i in range(res_size):
res[i] = __alphabet[0]
for i in range(full_block_count):
res = encode_block(data[(i*__fullBlockSize):(i*__fullBlockSize+__fullBlockSize)], res, i * __fullEncodedBlockSize)
if last_block_size > 0:
res = encode_block(data[(full_block_count*__fullBlockSize):(full_block_count*__fullBlockSize+last_block_size)], res, full_block_count * __fullEncodedBlockSize)
return _binToStr(res)
def decode_block(data, buf, index):
l_data = len(data)
if l_data < 1 or l_data > __fullEncodedBlockSize:
return "Invalid block length: " + l_data
res_size = __encodedBlockSizes.index(l_data)
if res_size <= 0:
return "Invalid block size"
res_num = 0
order = 1
for i in range(l_data-1, -1, -1):
digit = __alphabet.index(data[i])
if digit < 0:
return "Invalid symbol"
product = order * digit + res_num
if product > __UINT64MAX:
return "Overflow"
res_num = product
order = order * __b58base
if res_size < __fullBlockSize and 2**(8 * res_size) <= res_num:
return "Overflow 2"
tmp_buf = _uint64_to_8be(res_num, res_size)
for i in range(len(tmp_buf)):
buf[i+index] = tmp_buf[i]
return buf
def decode(enc):
'''Decode a base58 string (ex: a Monero address) into hexidecimal form.'''
enc = _strToBin(enc)
l_enc = len(enc)
if l_enc == 0:
return ""
full_block_count = l_enc // __fullEncodedBlockSize
last_block_size = l_enc % __fullEncodedBlockSize
last_block_decoded_size = __encodedBlockSizes.index(last_block_size)
if last_block_decoded_size < 0:
return "Invalid encoded length"
data_size = full_block_count * __fullBlockSize + last_block_decoded_size
data = [0] * data_size
for i in range(full_block_count):
data = decode_block(enc[(i*__fullEncodedBlockSize):(i*__fullEncodedBlockSize+__fullEncodedBlockSize)], data, i * __fullBlockSize)
if last_block_size > 0:
data = decode_block(enc[(full_block_count*__fullEncodedBlockSize):(full_block_count*__fullEncodedBlockSize+last_block_size)], data, full_block_count * __fullBlockSize)
return _binToHex(data)