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SSH Connections Thru The Firewall?
iamsure asks: "At my workplace, we have stringent rules on our firewall that filter out particular protocols (telnet/ssh being the one that is difficult for me). I actually work on the Security team, and as such, support such rules, as it helps reduce the number of incidents. However, I would very much like to access my machines from the outside via ssh, without making exceptions on the firewalls. After having tried http-tunnel (whose dual websites have gone offline, same for their server), and after having tried redirection of ports (the firewalls block the protocol, NOT the port), I am rather stumped. How does the rest of the slashdot reading public get through their firewalls?
There does seem to be a decent project underway at SocksViaHTTP , however, I was wondering if there are any other projects?"
Funny, I've just been talking to a few people about how silly fascist net admins prohibitting anything but http just causes everything to speak http...) to do just that. The one catch is that most web proxies will only let you connect via https to port 443 on the remote machine, so you need to be able to run sshd on that port.
Web proxies, due to mutual authentication concerns, generally give you a *straight* TCP connection when you go to connect via https. Therefore all you have to do is get ssh to walk the proxy. As it turns out, this is pretty easy and I've written a tool (http://www.snurgle.org/~griffon/ssh-https-tunnel
The tool is written in perl. It probably wouldn't be a horrible idea to rewrite it in C, but this one works pretty well, is easy to tweak, and seems fast enough.