OpenSSH server: how to configure keyboard-interactive authentication

Question

How can I configure the OpenSSH server (on Ubuntu) to allow keyboard-interactive but not password authentication?

I know that public-key-authentication is the preferred one, but I want to test a user setup.

Answer 1

Set ChallengeResponseAuthentication=yes in your sshd.conf I think

Answer 2

You need to configure PAM for use with OPIE or OTPW, depending on your Ubuntu version. Once you have a one-time password system in place and properly configured via the /etc/pam.d/sshd module, then you can setup SSH to make use of it.

# /etc/ssh/sshd_config
PasswordAuthentication no
ChallengeResponseAuthentication yes

Don't forget to reload SSH after making changes to the configuration file; otherwise, your changes will not take effect.