Sample pam.d system-auth

gistfile1.txt

auth            required        pam_env.so
auth            required        pam_unix.so try_first_pass likeauth nullok
auth            optional        pam_permit.so

account         required        pam_unix.so
account         optional        pam_permit.so

password        required        pam_cracklib.so difok=2 minlen=8 dcredit=2 ocredit=2 retry=3
password        required        pam_unix.so try_first_pass use_authtok nullok sha512 shadow
password        optional        pam_permit.so

session         required        pam_limits.so
session         required        pam_env.so
session         required        pam_unix.so
session         optional        pam_permit.so