Shut off SSH on a Linux server RHAS 3.0

[Jorge Cocomess]

In the past, whenever I used SSH to connect through another server, the server that I'm tryinh to connect to will ask for a password. Now, it just let me connect to another server without credential. I am very concern about the security of this server.

Therefore, I need to know how my remote login program SSH was modified and I can change so that it will ask for full credential like it used to be.

Sorry for this long text question.

Thanks,
J

[Steven E. Protter · Accepted solution]

Shalom J,

Someone, probably not you conducted a procedure to permit password free connections with ssh that involved exchanging public keys.

If you remove the file /root/.ssh/authorized_keys from the system it will stop permitting password free access.

The procedure is perfectly safe and permits people to administer multiple servers without remembering many passwords.

Prior to removing the file, I suggest you find out who did it and why. I do this to servers to permit scripts on one server to perform tasks on other servers. It permits better management and monitoring.

If you remove openssh, it will accomplish the goal of your question title but could deny you access to your server.

You may wish to read docs at http://www.openssh.org

SEP

[Ivan Ferreira]

It's very likely that public key authentication without passphrase was configured. To enable the password prompting, remove your public key or generate one new with a passphrase.

[Sung Oh]

Hello,

here is step by step procedure for how to make SSH without a password. This will explan what just happened to your system

http://www.csua.berkeley.edu/~ranga/notes/ssh_nopass.html

Regards,

Sung