Listing 2. Adding pam_access.so to the
account PAM checks lets you specify which users have SSH access to your
machine.

account  required    pam_unix2.so
account  required    pam_access.so

auth     required    pam_env.so
auth     required    pam_unix2.so
auth     required    pam_nologin.so

password requisite   pam_pwcheck.so nullok cracklib
password required    pam_unix2.so use_authtok nullok

session  required    pam_limits.so
session  required    pam_unix2.so
session  optional    pam_umask.so