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.

Solution 1

Set

ChallengeResponseAuthentication=yes 

in your sshd.conf

Solution 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.

Comments

[BennyInc]

keyboard-interactive but not password authentication? Can you rephrase that?

[barlop]

@BennyInc try looking at AuthenticationMethod in sshd_config it looks like they are distinct.