Duo Authentication Interactive Keyboard

Question

I'm trying to set up two factor authentication according to: https://duo.com/docs/duounix#pam-configuration

I'm running into an issue with the interactive keyboard. On Ubuntu 16.04

debug3: authmethod_lookup keyboard-interactive
debug3: remaining preferred: password
debug3: authmethod_is_enabled keyboard-interactive
debug1: Next authentication method: keyboard-interactive
debug2: userauth_kbdint
debug3: send packet: type 50
debug2: we sent a keyboard-interactive packet, wait for reply
debug3: receive packet: type 51
debug1: Authentications that can continue: keyboard-interactive
debug3: userauth_kbdint: disable: no info_req_seen
debug2: we did not send a packet, disable method
debug1: No more authentication methods to try.
Permission denied (keyboard-interactive).

I can't figure out where the issue is and I was wondering if anyone had any ideas. Normally, the following would prompt text that requests for a push notification. Seems like this is an issue with PAM. Thoughts are appreciated.

common-auth

auth  requisite pam_unix.so nullok_secure
auth  [success=1 default=ignore] pam_duo.so
auth  requisite pam_deny.so
auth  required pam_permit.so

and I've added this to the ssh pam file

auth  [success=1 default=ignore] pam_duo.so
auth  requisite pam_deny.so
auth  required pam_permit.so
# Disallow non-root logins when /etc/nologin exists.
account    required     pam_nologin.so//
auth  [success=1 default=ignore] pam_duo.so
auth  requisite pam_deny.so
auth  required pam_permit.so
# Disallow non-root logins when /etc/nologin exists.
account required pam_nologin.so

My sshd config file has

RSAAuthentication yes
PubkeyAuthentication yes
PasswordAuthentication no
#AuthorizedKeysFile     %h/.ssh/authorized_keys
AuthenticationMethods publickey,keyboard-interactive
UsePAM yes

Answer 1

I ran into the same issue. If you take a look in /var/log/auth.log you will see pam complaining about a missing pam_duo.so

Update all references in pam config of pam_duo.so to be /lib64/security/pam_duo.so