[CentOS] pam_tally2 after unlock time

Mon Feb 13 07:33:37 UTC 2017
Naveen Kumar <naveenmobi85 at gmail.com>

Hi All,

I prepared a Centos 6.8 Minimal server, as part of hardening i added PAM
rules under system-auth and password-auth to lock the user account for 30
minutes after 3 failed login attempts.

############system-auth###############
auth     required       pam_tally2.so deny=3 unlock_time=1800
auth        required      pam_env.so
auth        sufficient    pam_unix.so
auth        requisite     pam_succeed_if.so uid >= 500 quiet
auth        required      pam_deny.so

account     required      pam_unix.so
account     required      pam_tally2.so
account     sufficient    pam_localuser.so
account     sufficient    pam_succeed_if.so uid < 500 quiet
account     required      pam_permit.so

password    requisite     pam_cracklib.so try_first_pass retry=3 type=
password    sufficient    pam_unix.so sha512 shadow nullok use_authtok
password    required      pam_deny.so

session     optional      pam_keyinit.so revoke
session     required      pam_limits.so
session     [success=1 default=ignore] pam_succeed_if.so service in crond
quiet use_uid
session     required      pam_unix.so
###################password-auth#########
auth     required       pam_tally2.so deny=3 unlock_time=1800
auth        required      pam_env.so
auth        sufficient    pam_unix.so
auth        requisite     pam_succeed_if.so uid >= 500 quiet
auth        required      pam_deny.so

account     required      pam_unix.so
account     required      pam_tally2.so
account     sufficient    pam_localuser.so
account     sufficient    pam_succeed_if.so uid < 500 quiet
account     required      pam_permit.so

password    requisite     pam_cracklib.so try_first_pass retry=3 type=
password    sufficient    pam_unix.so sha512 shadow nullok use_authtok
password    required      pam_deny.so

session     optional      pam_keyinit.so revoke
session     required      pam_limits.so
session     [success=1 default=ignore] pam_succeed_if.so service in crond
quiet use_uid
session     required      pam_unix.so
#################################################################


Now, *after 3 failed attempts user locked successfully but after 30mins
when i tried with wrong password for first attempt it again got locked. It
should wait for 3 more attempts after unlock, but got locked after first
time,* after unlock. Anyway to correct the logic.