Rename more subpackages and modules

telethon/_network/connection/tcpmtproxy.py

@@ -0,0 +1,152 @@
+import asyncio
+import hashlib
+import os
+
+from .connection import ObfuscatedConnection
+from .tcpabridged import AbridgedPacketCodec
+from .tcpintermediate import (
+    IntermediatePacketCodec,
+    RandomizedIntermediatePacketCodec
+)
+
+from ...crypto import AESModeCTR
+
+
+class MTProxyIO:
+    """
+    It's very similar to tcpobfuscated.ObfuscatedIO, but the way
+    encryption keys, protocol tag and dc_id are encoded is different.
+    """
+    header = None
+
+    def __init__(self, connection):
+        self._reader = connection._reader
+        self._writer = connection._writer
+
+        (self.header,
+         self._encrypt,
+         self._decrypt) = self.init_header(
+             connection._secret, connection._dc_id, connection.packet_codec)
+
+    @staticmethod
+    def init_header(secret, dc_id, packet_codec):
+        # Validate
+        is_dd = (len(secret) == 17) and (secret[0] == 0xDD)
+        is_rand_codec = issubclass(
+            packet_codec, RandomizedIntermediatePacketCodec)
+        if is_dd and not is_rand_codec:
+            raise ValueError(
+                "Only RandomizedIntermediate can be used with dd-secrets")
+        secret = secret[1:] if is_dd else secret
+        if len(secret) != 16:
+            raise ValueError(
+                "MTProxy secret must be a hex-string representing 16 bytes")
+
+        # 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 = hashlib.sha256(
+            bytes(random[8:40]) + secret).digest()
+        encrypt_iv = bytes(random[40:56])
+        decrypt_key = hashlib.sha256(
+            bytes(random_reversed[:32]) + secret).digest()
+        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
+
+        dc_id_bytes = dc_id.to_bytes(2, "little", signed=True)
+        random = random[:60] + dc_id_bytes + random[62:]
+        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 TcpMTProxy(ObfuscatedConnection):
+    """
+    Connector which allows user to connect to the Telegram via proxy servers
+    commonly known as MTProxy.
+    Implemented very ugly due to the leaky abstractions in Telethon networking
+    classes that should be refactored later (TODO).
+
+    .. warning::
+
+        The support for TcpMTProxy classes is **EXPERIMENTAL** and prone to
+        be changed. You shouldn't be using this class yet.
+    """
+    packet_codec = None
+    obfuscated_io = MTProxyIO
+
+    # noinspection PyUnusedLocal
+    def __init__(self, ip, port, dc_id, *, loggers, proxy=None, local_addr=None):
+        # connect to proxy's host and port instead of telegram's ones
+        proxy_host, proxy_port = self.address_info(proxy)
+        self._secret = bytes.fromhex(proxy[2])
+        super().__init__(
+            proxy_host, proxy_port, dc_id, loggers=loggers)
+
+    async def _connect(self, timeout=None, ssl=None):
+        await super()._connect(timeout=timeout, ssl=ssl)
+
+        # Wait for EOF for 2 seconds (or if _wait_for_data's definition
+        # is missing or different, just sleep for 2 seconds). This way
+        # we give the proxy a chance to close the connection if the current
+        # codec (which the proxy detects with the data we sent) cannot
+        # be used for this proxy. This is a work around for #1134.
+        # TODO Sleeping for N seconds may not be the best solution
+        # TODO This fix could be welcome for HTTP proxies as well
+        try:
+            await asyncio.wait_for(self._reader._wait_for_data('proxy'), 2)
+        except asyncio.TimeoutError:
+            pass
+        except Exception:
+            await asyncio.sleep(2)
+
+        if self._reader.at_eof():
+            await self.disconnect()
+            raise ConnectionError(
+                'Proxy closed the connection after sending initial payload')
+
+    @staticmethod
+    def address_info(proxy_info):
+        if proxy_info is None:
+            raise ValueError("No proxy info specified for MTProxy connection")
+        return proxy_info[:2]
+
+
+class ConnectionTcpMTProxyAbridged(TcpMTProxy):
+    """
+    Connect to proxy using abridged protocol
+    """
+    packet_codec = AbridgedPacketCodec
+
+
+class ConnectionTcpMTProxyIntermediate(TcpMTProxy):
+    """
+    Connect to proxy using intermediate protocol
+    """
+    packet_codec = IntermediatePacketCodec
+
+
+class ConnectionTcpMTProxyRandomizedIntermediate(TcpMTProxy):
+    """
+    Connect to proxy using randomized intermediate protocol (dd-secrets)
+    """
+    packet_codec = RandomizedIntermediatePacketCodec