Summerschool Aachen 2004/Project Day I
HTTP Tunnelling
I was planning to implement in my project first a simple program and then extend it to a more "advanced" program: Assume we have a host H1 behind a firewall F who wants to communicate with a host H2 who is outside the firewall. Let us further assume that the firewall F only lets HTTP packets through, i.e. packets with destination port 80, and assume that host H1 wants to build up an SSH connection with host H2. I want first to write a (static) C program run on a host X between host H1 and H2, such that H1 can contact build up an SSH connection with X at port 80 (meaning that the traffic will be let through by F) and X forwards the traffic to H2 at port 22. F should also forward the traffic from H2 to H1. Later I want to extend this program to a more dynamic program in a way that H1 can tell X with whom he wants to build up an SSH connection and X does this. If there is still some time left (which I hope there will be :)) I would like to extend that program to a more generic program which cannot only forward SSH traffic but also SMTP and other kinds of traffic. I know that there are probably already many tunnelling programs doing such kinds of things. However, as I don't have that much experience of network programming (except a small webserver I have once set up in Java) I think that such a project will help me to improve my skills in network programming.
