mirror of
https://github.com/LonamiWebs/Telethon.git
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63 lines
2.0 KiB
Python
63 lines
2.0 KiB
Python
import os
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from .tcpabridged import AbridgedPacketCodec
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from .connection import ObfuscatedConnection
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from ...crypto import AESModeCTR
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class ObfuscatedIO:
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header = None
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def __init__(self, connection):
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self._reader = connection._reader
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self._writer = connection._writer
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(self.header,
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self._encrypt,
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self._decrypt) = self.init_header(connection.packet_codec)
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@staticmethod
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def init_header(packet_codec):
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# Obfuscated messages secrets cannot start with any of these
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keywords = (b'PVrG', b'GET ', b'POST', b'\xee\xee\xee\xee')
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while True:
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random = os.urandom(64)
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if (random[0] != 0xef and
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random[:4] not in keywords and
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random[4:4] != b'\0\0\0\0'):
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break
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random = bytearray(random)
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random_reversed = random[55:7:-1] # Reversed (8, len=48)
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# Encryption has "continuous buffer" enabled
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encrypt_key = bytes(random[8:40])
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encrypt_iv = bytes(random[40:56])
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decrypt_key = bytes(random_reversed[:32])
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decrypt_iv = bytes(random_reversed[32:48])
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encryptor = AESModeCTR(encrypt_key, encrypt_iv)
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decryptor = AESModeCTR(decrypt_key, decrypt_iv)
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random[56:60] = packet_codec.obfuscate_tag
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random[56:64] = encryptor.encrypt(bytes(random))[56:64]
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return (random, encryptor, decryptor)
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async def readexactly(self, n):
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return self._decrypt.encrypt(await self._reader.readexactly(n))
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def write(self, data):
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self._writer.write(self._encrypt.encrypt(data))
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class ConnectionTcpObfuscated(ObfuscatedConnection):
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"""
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Mode that Telegram defines as "obfuscated2". Encodes the packet
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just like `ConnectionTcpAbridged`, but encrypts every message with
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a randomly generated key using the AES-CTR mode so the packets are
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harder to discern.
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"""
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obfuscated_io = ObfuscatedIO
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packet_codec = AbridgedPacketCodec
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