Rename more subpackages and modules

telethon/_network/connection/tcpobfuscated.py

@@ -0,0 +1,62 @@
+import os
+
+from .tcpabridged import AbridgedPacketCodec
+from .connection import ObfuscatedConnection
+
+from ...crypto import AESModeCTR
+
+
+class ObfuscatedIO:
+    header = None
+
+    def __init__(self, connection):
+        self._reader = connection._reader
+        self._writer = connection._writer
+
+        (self.header,
+         self._encrypt,
+         self._decrypt) = self.init_header(connection.packet_codec)
+
+    @staticmethod
+    def init_header(packet_codec):
+        # 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[4:8] != 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 = bytes(random[8:40])
+        encrypt_iv = bytes(random[40:56])
+        decrypt_key = bytes(random_reversed[:32])
+        decrypt_iv = bytes(random_reversed[32:48])
+
+        encryptor = AESModeCTR(encrypt_key, encrypt_iv)
+        decryptor = AESModeCTR(decrypt_key, decrypt_iv)
+
+        random[56:60] = packet_codec.obfuscate_tag
+        random[56:64] = encryptor.encrypt(bytes(random))[56:64]
+        return (random, encryptor, decryptor)
+
+    async def readexactly(self, n):
+        return self._decrypt.encrypt(await self._reader.readexactly(n))
+
+    def write(self, data):
+        self._writer.write(self._encrypt.encrypt(data))
+
+
+class ConnectionTcpObfuscated(ObfuscatedConnection):
+    """
+    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.
+    """
+    obfuscated_io = ObfuscatedIO
+    packet_codec = AbridgedPacketCodec