Add support for proxy again

telethon/network/connection/connection.py

@@ -1,7 +1,8 @@
 import abc
 import asyncio
 import logging
-
+import socket
+import ssl as ssl_mod
 
 __log__ = logging.getLogger(__name__)
 
@@ -16,11 +17,11 @@ class Connection(abc.ABC):
     under any conditions for as long as the user doesn't disconnect or
     the input parameters to auto-reconnect dictate otherwise.
     """
-    # TODO Support proxy
-    def __init__(self, ip, port, *, loop):
+    def __init__(self, ip, port, *, loop, proxy=None):
         self._ip = ip
         self._port = port
         self._loop = loop
+        self._proxy = proxy
         self._reader = None
         self._writer = None
         self._disconnected = asyncio.Event(loop=loop)
@@ -31,14 +32,48 @@ class Connection(abc.ABC):
         self._send_queue = asyncio.Queue(1)
         self._recv_queue = asyncio.Queue(1)
 
-    async def connect(self, timeout=None):
+    async def connect(self, timeout=None, ssl=None):
         """
         Establishes a connection with the server.
         """
-        self._reader, self._writer = await asyncio.wait_for(
-            asyncio.open_connection(self._ip, self._port, loop=self._loop),
-            loop=self._loop, timeout=timeout
-        )
+        if not self._proxy:
+            self._reader, self._writer = await asyncio.wait_for(
+                asyncio.open_connection(
+                    self._ip, self._port, loop=self._loop, ssl=ssl),
+                loop=self._loop, timeout=timeout
+            )
+        else:
+            import socks
+            if ':' in self._ip:
+                mode, address = socket.AF_INET6, (self._ip, self._port, 0, 0)
+            else:
+                mode, address = socket.AF_INET, (self._ip, self._port)
+
+            s = socks.socksocket(mode, socket.SOCK_STREAM)
+            if isinstance(self._proxy, dict):
+                s.set_proxy(**self._proxy)
+            else:
+                s.set_proxy(*self._proxy)
+
+            s.setblocking(False)
+            await asyncio.wait_for(
+                self._loop.sock_connect(s, address),
+                timeout=timeout,
+                loop=self._loop
+            )
+            if ssl:
+                self._socket.settimeout(timeout)
+                self._socket = ssl_mod.wrap_socket(
+                    s,
+                    do_handshake_on_connect=True,
+                    ssl_version=ssl_mod.PROTOCOL_SSLv23,
+                    ciphers='ADH-AES256-SHA'
+                )
+                self._socket.setblocking(False)
+
+            self._reader, self._writer = await asyncio.open_connection(
+                self._ip, self._port, loop=self._loop, sock=s
+            )
 
         self._disconnected.clear()
         self._disconnected_future = None