Sam Hocevar’s .plan
Posted on Mon, 23 Apr 2007 17:50:25 +0200 - Keywords: debian, devel
sshd on port 443 is common practice, because even
in a very hostile environment full of firewalls and proxies that only allow
web access, it is usually possible to use the HTTPS proxy to open a full TCP
connection to port 443. I use this a lot. The problem is that I also want to
run my SSL web server on the same IP. Here is a hack to do both.
One essential difference between the SSH and HTTP/HTTPS protocols is that upon connection the SSH server sends a banner to the client, while the HTTP and HTTPS servers wait for the client to send a request. Which means that after a reasonable amount of time, one can be fairly sure the client at the other end talks HTTP/HTTPS or SSH.
Due to recent interest in it, I’m publishing redirect.c, a small program that implements this technique. Use it at your own risk, and read about the limitations.