How to create a simple and secure Socks5 proxy in python?

Question

Few days back I was wanting to build a proxy that could allow me to securely and anonymously connect to websites and servers. At first it seemed like a pretty easy idea, I would create an HTTP proxy that uses SSL between the client and the proxy, It would then create a SSL connection with what ever website/server the client requested and then forward that information to and from the client and server. I spent about a day researching and writing code that would do just that. But I then realized that someone could compromise the proxy and use the session key that the proxy had to decrypt and read the data being sent to and from the server.

After a little more research it seem that a socks proxy is what I needed. However there is not much documentation on a python version of a socks proxy(Mostly just how to connect to one). I was able to find The PySocks Module and read the Socks.py file. It looks great for creating a client but I don't see how I could use it to make a proxy.

I was wondering if anyone had a simple example of a socks5 proxy or if someone could point me to some material that could help me begin learning and building one?

Answer 1

You create a python server to listen on a port and listen on IP 127.0.0.1. When you connect to your server you send: "www.facebook.com:80". No URL path nor http scheme. If the connect fails you send a failure message which may look something like "number Unable to connect to host." where number is an specific code that signifies a failed connection attempt. Upon success of a connection you send "200 Connection established". Then data is sent and received as normal. You do not want to use an http proxy because it accepts only website traffic.

You may want to use a framework for the proxy server because it should handle multiple connections.

I've read an ebook on asyncio named O'Reilly "Using Asyncio In Python 2020" multiple times and re-read it every now and again to try to grasp multiple connections. I have also just started to search for solutions using Flask because I want my proxy server to run along side a webserver.