One user is having repeated failures when trying to log onto a server protected by Duo. The failures are limited to the one user. No one else seems to be having any problems.
I tried in no particular order:
- restarting sshd
- disabling selinux.
- Resetting user password
- Setting user password to empty string
- Search Engines…
None of it worked. The one user still cannot log in.
There is nothing unsusual I can see in the account and the user only uses the target as a jump host.
Typical entries from sshd.log:
Sep 16 06:24:34 scajump01 sshd[1321830]: pam_duo(sshd:auth): conversation failed
Sep 16 06:24:34 scajump01 sshd[1321830]: Aborted Duo login for 'kbowser' from 10.222.79.74: Error gathering user response
Sep 16 06:24:34 scajump01 sshd[1321830]: Failed password for kbowser from 10.222.79.74 port 52388 ssh2
Sep 16 06:24:38 scajump01 sshd[1321830]: Connection closed by authenticating user kbowser 10.222.79.74 port 52388 [preauth]
ChallengeResponseAuthentication in sshd_config is set to yes.
/etc/pam.d/sshd
#%PAM-1.0
auth required pam_sepermit.so
# auth substack password-auth
auth required pam_env.so
auth sufficient pam_duo.so
auth required pam_deny.so
auth include postlogin
account required pam_sepermit.so
account required pam_nologin.so
account include password-auth
password include password-auth
# pam_selinux.so close should be the[duo]
first session rule
session required pam_selinux.so close
session required pam_loginuid.so
# pam_selinux.so open should only be followed by sessions to be executed in the user context
session required pam_selinux.so open env_params
session required pam_namespace.so
session optional pam_keyinit.so force revoke
session optional pam_motd.so
session include password-auth
session include postlogin
/etc/duo/pam_duo.conf (ikey, skey, and host values are bogus)
; Duo integration key
ikey = ENCRPLKHZIOHWBTVJTUZ
; Duo secret key
■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■■
; Duo API host
host = ■■■■■■■■■■■■■■■■■■■■■■■■■■■■
failmode = safe
; Send command for Duo Push authentication
pushinfo = yes
