fastapi/dependencies/moneropy.py

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2023-03-10 10:46:21 +00:00
# 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.
#
# Modified by emesik and rooterkyberian:
# + optimized
# + proper exceptions instead of returning errors as results
__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:
raise ValueError("Hex string has invalid length: %d" % len(hex_))
return [int(hex_[i : i + 2], 16) for i in range(0, len(hex_), 2)]
def _binToHex(bin_):
return "".join("%02x" % int(b) for b in bin_)
def _uint8be_to_64(data):
if not (1 <= len(data) <= 8):
raise ValueError("Invalid input length: %d" % len(data))
res = 0
for b in data:
res = res << 8 | b
return res
def _uint64_to_8be(num, size):
if size < 1 or size > 8:
raise ValueError("Invalid input length: %d" % size)
res = [0] * size
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:
raise ValueError("Invalid block length: %d" % 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 = bytearray([__alphabet[0]] * res_size)
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 bytes(res).decode("ascii")
def decode_block(data, buf, index):
l_data = len(data)
if l_data < 1 or l_data > __fullEncodedBlockSize:
raise ValueError("Invalid block length: %d" % l_data)
res_size = __encodedBlockSizes.index(l_data)
if res_size <= 0:
raise ValueError("Invalid block size: %d" % res_size)
res_num = 0
order = 1
for i in range(l_data - 1, -1, -1):
digit = __alphabet.index(data[i])
if digit < 0:
raise ValueError("Invalid symbol: %s" % data[i])
product = order * digit + res_num
if product > __UINT64MAX:
raise ValueError(
"Overflow: %d * %d + %d = %d" % (order, digit, res_num, product)
)
res_num = product
order = order * __b58base
if res_size < __fullBlockSize and 2 ** (8 * res_size) <= res_num:
raise ValueError("Overflow: %d doesn't fit in %d bit(s)" % (res_num, res_size))
tmp_buf = _uint64_to_8be(res_num, res_size)
buf[index : index + len(tmp_buf)] = tmp_buf
return buf
def decode(enc):
"""Decode a base58 string (ex: a Monero address) into hexidecimal form."""
enc = bytearray(enc, encoding="ascii")
l_enc = len(enc)
if l_enc == 0:
return ""
full_block_count = l_enc // __fullEncodedBlockSize
last_block_size = l_enc % __fullEncodedBlockSize
try:
last_block_decoded_size = __encodedBlockSizes.index(last_block_size)
except ValueError:
raise ValueError("Invalid encoded length: %d" % l_enc)
data_size = full_block_count * __fullBlockSize + last_block_decoded_size
data = bytearray(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)