MTPyroger/pyrogram/crypto/aes.py

136 lines
4.5 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
log.info("Using TgCrypto")
class AES:
# TODO: Use new tgcrypto function names
@classmethod
def ige256_encrypt(cls, data: bytes, key: bytes, iv: bytes) -> bytes:
return tgcrypto.ige_encrypt(data, key, iv)
@classmethod
def ige256_decrypt(cls, data: bytes, key: bytes, iv: bytes) -> bytes:
return tgcrypto.ige_decrypt(data, key, iv)
@staticmethod
def ctr256_encrypt(data: bytes, key: bytes, iv: bytearray, state: bytearray = None) -> bytes:
return tgcrypto.ctr_encrypt(data, key, iv, state or bytearray(1))
@staticmethod
def ctr256_decrypt(data: bytes, key: bytes, iv: bytearray, state: bytearray = None) -> bytes:
return tgcrypto.ctr_decrypt(data, key, iv, state or bytearray(1))
@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",
)
except ImportError:
import pyaes
log.warning(
"TgCrypto is missing! "
"Pyrogram will work the same, but at a much slower speed. "
"More info: https://docs.pyrogram.ml/resources/TgCrypto"
)
class AES:
@classmethod
def ige256_encrypt(cls, data: bytes, key: bytes, iv: bytes) -> bytes:
return cls.ige(data, key, iv, True)
@classmethod
def ige256_decrypt(cls, data: bytes, key: bytes, iv: bytes) -> bytes:
return cls.ige(data, key, iv, False)
@classmethod
def ctr256_encrypt(cls, data: bytes, key: bytes, iv: bytearray, state: bytearray = None) -> bytes:
return cls.ctr(data, key, iv, state or bytearray(1))
@classmethod
def ctr256_decrypt(cls, data: bytes, key: bytes, iv: bytearray, state: bytearray = None) -> bytes:
return cls.ctr(data, key, iv, state or bytearray(1))
@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)
@classmethod
def ctr(cls, data: bytes, key: bytes, iv: bytearray, state: bytearray) -> bytes:
cipher = pyaes.AES(key)
out = bytearray(data)
chunk = cipher.encrypt(iv)
for i in range(0, len(data), 16):
for j in range(0, min(len(data) - i, 16)):
out[i + j] ^= chunk[state[0]]
state[0] += 1
if state[0] >= 16:
state[0] = 0
if state[0] == 0:
for k in range(15, -1, -1):
try:
iv[k] += 1
break
except ValueError:
iv[k] = 0
chunk = cipher.encrypt(iv)
return out