text: import os
  
  from .connection import Connection
  from .tcpabridged import ConnectionTcpAbridged
  from ...crypto import AESModeCTR
  
  
  class ConnectionTcpObfuscated(ConnectionTcpAbridged):
      """
      Mode that Telegram defines as "obfuscated2". Encodes the packet
      just like `ConnectionTcpAbridged`, but encrypts every message with
      a randomly generated key using the AES-CTR mode so the packets are
      harder to discern.
      """
      def __init__(self, ip, port, dc_id, *, loop, loggers, proxy=None):
          super().__init__(
              ip, port, dc_id, loop=loop, loggers=loggers, proxy=proxy)
          self._aes_encrypt = None
          self._aes_decrypt = None
  
      def _write(self, data):
          self._writer.write(self._aes_encrypt.encrypt(data))
  
      async def _read(self, n):
          return self._aes_decrypt.encrypt(await self._reader.readexactly(n))
  
      async def connect(self, timeout=None, ssl=None):
          # FIXME: that's an abstraction leak
          await Connection.connect(self, timeout=timeout, ssl=ssl)
  
          # Obfuscated messages secrets cannot start with any of these
          keywords = (b'PVrG', b'GET ', b'POST', b'\xee\xee\xee\xee')
          while True:
              random = os.urandom(64)
              if (random[0] != 0xef and
                      random[:4] not in keywords and
                      random[4:4] != b'\0\0\0\0'):
                  break
  
          random = bytearray(random)
          random_reversed = random[55:7:-1]  # Reversed (8, len=48)
  
          # Encryption has "continuous buffer" enabled
          encrypt_key = self._compose_key(bytes(random[8:40]))
          encrypt_iv = bytes(random[40:56])
          decrypt_key = self._compose_key(bytes(random_reversed[:32]))
          decrypt_iv = bytes(random_reversed[32:48])
  
          self._aes_encrypt = AESModeCTR(encrypt_key, encrypt_iv)
          self._aes_decrypt = AESModeCTR(decrypt_key, decrypt_iv)
  
          random[56:60] = b'\xef\xef\xef\xef'
          random[56:64] = self._compose_tail(bytes(random))
  
          self._writer.write(random)
          await self._writer.drain()
  
      # Next functions provide the variable parts of the connection handshake.
      # This is necessary to modify obfuscated2 the way that MTProxy requires.
      def _compose_key(self, data):
          return data
  
      def _compose_tail(self, data):
          return self._aes_encrypt.encrypt(data)[56:64]
  