Port forwarding using subdomain

Senth · 11-27-2006, 11:27 AM

I got a "simple" problem, to help you understand it I'll first draw the problem.

School (only allowing port 80 out)
->
Router (Forwarding port 80 to server)
->
Server (Displays my home page (Apache) and has a ssh server)

Since I wan't to get access to my server while I'm at the school I need to ssh it. But that won't work since they blocked all the ports except port 80. I can't use ssh at port 80 (at least not at the server since I got a homepage).

Example:
Connecting to my ssh server from school using port 80 via sshDOTmy-domainDOTorg
Then my server checks which subdomain is used and if it's ssh it'll forward it to port 22

Is this possible?

I'm quite new to Linux, in other words a newbie.

Thanks for the help

jschiwal · 11-27-2006, 12:39 PM

Would a web based ssh proxy be useful?
http://sourceforge.net/projects/sshwebproxy

chort · 11-27-2006, 01:02 PM

It's not possible to forward services based on what name the client used to access it, since the packets arrive addressed by IP, not by hostname (hostnames are client-side conventions, mostly). What you need is either a second IP address, or to be able to use other port numbers. I'm betting port 443 might be available. As long as you're not trying to host any SSL-enabled sites in Apache, you could simply add another port to SSH in /etc/ssh/sshd_config. Here's a snippet:

Code:

old:
#Port 22
#Protocol 2,1
#ListenAddress 0.0.0.0
#ListenAddress ::
...

new:
Port 22
Port 443
Protocol 2
#ListenAddress 0.0.0.0
#ListenAddress ::
...

The only other option would be a TCP proxy running from Apache on a hidden page of your website. You sure wouldn't want a link to such a thing or it will be abused.