It is interesting to note in Firefox, that any service that terminates immediately after connecting (i.e. postgresql and sshd) can be used in port scanning. JSWebPing can be used to test this. Obviously sshd had to be setup on another port for this test.

It is definately an interesting area.

Thanks pdp, your bi-directional project is rather interesting… I must have a chat to you about it, I have a few thoughts in that area.

Real world testing to see if browser will connect to port 22 on localhost:

IE 7.0.5450.4 (win2k3) refuses to connect
FF 1.5.0.6 refuses saying its restricted
Camino 1.0.3 refuses (built on FF framework, so expected same results as FF)
Safari 2.0.4 happily does a GET / HTTP/1.1 to the port

Interesting, so Safari here isn’t following protocol and playing nicely.

What happens when i try a non-standard port, hmmm 666 sounds good:

IE 7.0.5450.4 (win2k3) Tries to connect, but returns an error
FF 1.5.0.6 does a GET, but returns an error
Camino 1.0.3 happily does a GET / HTTP/1.1 to the port
Safari 2.0.4 happily does a GET / HTTP/1.1 to the port