Ssh – Determining the Password Status of a User

debianpasswordssh

I have a debian box that I connect to via SSH. I have removed the password from the users root, and my personal account using the instructions here, and set up a public/private key pair so I can log in, but only if I have the private key.

I recently ran cat /etc/passwd in order to see what other users where on the system, and got a fair list back. So, how can I determine the password status for each user so that if I make the box public to the wider world (via ssh only), there are no other users that someone could use to authenticate with?

Best Answer

Probably you should look at sshd configuration.

There is an option to deny password authentication:

PasswordAuthentication no

and you can create a list of users that are allowed to connect via ssh:

AllowUsers cgoddard

Related Solutions

Ssh – Permit root to login via ssh only with key-based authentication

You can do this using the PermitRootLogin directive. From the sshd_config manpage:

Specifies whether root can log in using ssh(1). The argument must be “yes”, “without-password”, “forced-commands-only”, or “no”. The default is “yes”.

If this option is set to “without-password”, password authentication is disabled for root.

The following will accomplish what you want:

PasswordAuthentication yes
PermitRootLogin without-password

Ssh – “Permanently added the RSA host key” what does it mean

Keyword there is host key. The first time you connect to a host, you are presented with a fingerprint of that host's public key. The server itself has a keypair just like users do.

The idea is that you can verify the fingerprint with what you know that server's fingerprint to be, to ensure you are not being MITMed.

Once you accept the host key, it gets saved in your known_hosts file, which your client uses to verify all subsequent connections.

If the host key changes unexpectedly, your client will notice and will display a nasty error message, suggesting that something may be awry and that you should check things out.

Best Answer

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Ssh – Permit root to login via ssh only with key-based authentication

Ssh – “Permanently added the RSA host key” what does it mean

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