89 lines
2.7 KiB
Python
89 lines
2.7 KiB
Python
# Pyrogram - Telegram MTProto API Client Library for Python
|
|
# Copyright (C) 2017-2018 Dan Tès <https://github.com/delivrance>
|
|
#
|
|
# This file is part of Pyrogram.
|
|
#
|
|
# Pyrogram is free software: you can redistribute it and/or modify
|
|
# it under the terms of the GNU Lesser General Public License as published
|
|
# by the Free Software Foundation, either version 3 of the License, or
|
|
# (at your option) any later version.
|
|
#
|
|
# Pyrogram is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU Lesser General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU Lesser General Public License
|
|
# along with Pyrogram. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
import logging
|
|
|
|
log = logging.getLogger(__name__)
|
|
|
|
try:
|
|
import tgcrypto
|
|
except ImportError:
|
|
logging.warning("Warning: TgCrypto is missing")
|
|
is_fast = False
|
|
import pyaes
|
|
else:
|
|
log.info("Using TgCrypto")
|
|
is_fast = True
|
|
|
|
|
|
# TODO: Ugly IFs
|
|
class AES:
|
|
@classmethod
|
|
def ige_encrypt(cls, data: bytes, key: bytes, iv: bytes) -> bytes:
|
|
if is_fast:
|
|
return tgcrypto.ige_encrypt(data, key, iv)
|
|
else:
|
|
return cls.ige(data, key, iv, True)
|
|
|
|
@classmethod
|
|
def ige_decrypt(cls, data: bytes, key: bytes, iv: bytes) -> bytes:
|
|
if is_fast:
|
|
return tgcrypto.ige_decrypt(data, key, iv)
|
|
else:
|
|
return cls.ige(data, key, iv, False)
|
|
|
|
@staticmethod
|
|
def ctr_decrypt(data: bytes, key: bytes, iv: bytes, offset: int) -> bytes:
|
|
replace = int.to_bytes(offset // 16, byteorder="big", length=4)
|
|
iv = iv[:-4] + replace
|
|
|
|
if is_fast:
|
|
return tgcrypto.ctr_decrypt(data, key, iv)
|
|
else:
|
|
ctr = pyaes.AESModeOfOperationCTR(key)
|
|
ctr._counter._counter = list(iv)
|
|
return ctr.decrypt(data)
|
|
|
|
@staticmethod
|
|
def xor(a: bytes, b: bytes) -> bytes:
|
|
return int.to_bytes(
|
|
int.from_bytes(a, "big") ^ int.from_bytes(b, "big"),
|
|
len(a),
|
|
"big",
|
|
)
|
|
|
|
@classmethod
|
|
def ige(cls, data: bytes, key: bytes, iv: bytes, encrypt: bool) -> bytes:
|
|
cipher = pyaes.AES(key)
|
|
|
|
iv_1 = iv[:16]
|
|
iv_2 = iv[16:]
|
|
|
|
data = [data[i: i + 16] for i in range(0, len(data), 16)]
|
|
|
|
if encrypt:
|
|
for i, chunk in enumerate(data):
|
|
iv_1 = data[i] = cls.xor(cipher.encrypt(cls.xor(chunk, iv_1)), iv_2)
|
|
iv_2 = chunk
|
|
else:
|
|
for i, chunk in enumerate(data):
|
|
iv_2 = data[i] = cls.xor(cipher.decrypt(cls.xor(chunk, iv_2)), iv_1)
|
|
iv_1 = chunk
|
|
|
|
return b"".join(data)
|