pam_unix comes as one module pam_unix.so.
The following links are left for compatibility with old versions:
pam_unix_auth: authentication module providing
pam_authenticate() and pam_setcred() hooks
pam_unix_sess: session module, providing session logging
pam_unix_acct: account management, providing shadow account
managment features, password aging etc..
pam_unix_passwd: password updating facilities providing
cracklib password strength checking facilities.
The following options are recognized:
debug - log more debugging info
audit - a little more extreme than debug
use_first_pass - don't prompt the user for passwords
take them from PAM_ items instead
try_first_pass - don't prompt the user for the passwords
unless PAM_(OLD)AUTHTOK is unset
use_authtok - like try_first_pass, but * fail * if the new
PAM_AUTHTOK has not been previously set.
(intended for stacking password modules only)
not_set_pass - don't set the PAM_ items with the passwords
used by this module.
shadow - try to maintian a shadow based system.
md5 - when a user changes their password next,
encrypt it with the md5 algorithm.
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