1

I've followed several different guides on how to configure two factor authentication on my ssh server using the google's libpam-google-authenticator. I've been able to get it to work but when I try and log in from my desktop or any other device over the ssh I have to give it my ssh-key, user password, and then the authenticator token. But in my sshd_config file I have:

AuthenticationMethods publickey,keyboard-interactive  
ChallengeResponseAuthentication yes  
PasswordAuthentication no   
UsePAM yes

And in my /etc/pam.d/sshd I added

auth required pam_google_authenticator.so

So I think it should not ask for password as well. How can I fix it?

2
  • What is your question here?
    – cornelinux
    Oct 16, 2016 at 9:07
  • I dont want it asking for the password only my ssh key and the authentication token Oct 16, 2016 at 10:46

2 Answers 2

1

Comment out the line @include common-auth from your /etc/pam.d/sshd. It will ask only for the second factor (if configured!).

0

Basically @Jakuje is right.

The common-auth contains a line with pam_unix.so. I would create a new file /etc/pam.d/google_auth and include this in your /etc/pam.d/sshd instead of common-auth. This way you are more modular.

The google-auth would basically look like this:

# here are the per-package modules (the "Primary" block)
auth    [success=1 default=ignore]     pam_google_authenticator.so
# here's the fallback if no module succeeds
auth    requisite                       pam_deny.so
# prime the stack with a positive return value if there isn't one    
# this avoids us returning an error just because nothing sets a success code
# since the modules above will each just jump around
auth    required                        pam_permit.so
# and here are more per-package modules (the "Additional" block)
auth    optional                        pam_cap.so
# end of pam-auth-update config

This way you can include the google-authin whichever service you like to.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .