DirectAdmin over SSH fails to log-in

[jtara]

I'm trying to set up a relatively secure site. It's a Xen-based virtual server.

I'm starting by turning off unnecessary services (for example, FTP, since I use SFTP and have no need to provide FTP service to users).

The site uses DirectAdmin. I'd like to access DirectAdmin over an SSH tunnel, and disable access to the outside world. (i.e. I will only allow a connection from 127.0.0.1). I've set port 2222 locally to forward to 2222 on the server.

I am using a popular commercial Telnet/SSH client that supports SSH tunnels.

I can get the login screen through the tunnel. When I attempt to login, though, I just get another login screen, and the follow error message in the DirectAdmin security log:

2006:02:02-07:12:12: *** 127.0.0.1 has tried to login with an invalid username: '(null)' ***

I have no problem logging in to DirectAdmin over the (currently) exposted port 2222 over the Internet.

Any idea what is wrong?

I have tested access to Apache through the tunnel, which works fine. (Though I haven't tested it with authentication.)

P.S. Here's something else strange I have noticed. Even when I log on to Directadmin successfully over the public Internet address, I still get an error message, even though I am successfully logged-on:

2006:02:02-07:34:39: *** yyy.yyy.yyy.yyy has tried to login with an invalid username: '' ***