pam_tally(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | MODULE TYPES PROVIDED | RETURN VALUES | EXAMPLES | FILES | SEE ALSO | AUTHOR | COLOPHON

PAM_TALLY(8)                Linux-PAM Manual                PAM_TALLY(8)

NAME         top

       pam_tally - The login counter (tallying) module

SYNOPSIS         top

       pam_tally.so [file=/path/to/counter] [onerr=[fail|succeed]]
                    [magic_root] [even_deny_root_account] [deny=n]
                    [lock_time=n] [unlock_time=n] [per_user]
                    [no_lock_time] [no_reset] [audit] [silent]
                    [no_log_info]

       pam_tally [--file /path/to/counter] [--user username]
                 [--reset[=n]] [--quiet]

DESCRIPTION         top

       This module maintains a count of attempted accesses, can reset
       count on success, can deny access if too many attempts fail.

       pam_tally has several limitations, which are solved with
       pam_tally2. For this reason pam_tally is deprecated and will be
       removed in a future release.

       pam_tally comes in two parts: pam_tally.so and pam_tally. The
       former is the PAM module and the latter, a stand-alone program.
       pam_tally is an (optional) application which can be used to
       interrogate and manipulate the counter file. It can display user
       counts, set individual counts, or clear all counts. Setting
       artificially high counts may be useful for blocking users without
       changing their passwords. For example, one might find it useful
       to clear all counts every midnight from a cron job. The
       faillog(8) command can be used instead of pam_tally to to
       maintain the counter file.

       Normally, failed attempts to access root will not cause the root
       account to become blocked, to prevent denial-of-service: if your
       users aren't given shell accounts and root may only login via su
       or at the machine console (not telnet/rsh, etc), this is safe.

OPTIONS         top

       GLOBAL OPTIONS
           This can be used for auth and account module types.

           onerr=[fail|succeed]
               If something weird happens (like unable to open the
               file), return with PAM_SUCCESS if onerr=succeed is given,
               else with the corresponding PAM error code.

           file=/path/to/counter
               File where to keep counts. Default is /var/log/faillog.

           audit
               Will log the user name into the system log if the user is
               not found.

           silent
               Don't print informative messages.

           no_log_info
               Don't log informative messages via syslog(3).

       AUTH OPTIONS
           Authentication phase first checks if user should be denied
           access and if not it increments attempted login counter. Then
           on call to pam_setcred(3) it resets the attempts counter.

           deny=n
               Deny access if tally for this user exceeds n.

           lock_time=n
               Always deny for n seconds after failed attempt.

           unlock_time=n
               Allow access after n seconds after failed attempt. If
               this option is used the user will be locked out for the
               specified amount of time after he exceeded his maximum
               allowed attempts. Otherwise the account is locked until
               the lock is removed by a manual intervention of the
               system administrator.

           magic_root
               If the module is invoked by a user with uid=0 the counter
               is not incremented. The sysadmin should use this for user
               launched services, like su, otherwise this argument
               should be omitted.

           no_lock_time
               Do not use the .fail_locktime field in /var/log/faillog
               for this user.

           no_reset
               Don't reset count on successful entry, only decrement.

           even_deny_root_account
               Root account can become unavailable.

           per_user
               If /var/log/faillog contains a non-zero
               .fail_max/.fail_locktime field for this user then use it
               instead of deny=n/ lock_time=n parameter.

           no_lock_time
               Don't use .fail_locktime filed in /var/log/faillog for
               this user.

       ACCOUNT OPTIONS
           Account phase resets attempts counter if the user is not
           magic root. This phase can be used optionally for services
           which don't call pam_setcred(3) correctly or if the reset
           should be done regardless of the failure of the account phase
           of other modules.

           magic_root
               If the module is invoked by a user with uid=0 the counter
               is not incremented. The sysadmin should use this for user
               launched services, like su, otherwise this argument
               should be omitted.

           no_reset
               Don't reset count on successful entry, only decrement.

MODULE TYPES PROVIDED         top

       The auth and account module types are provided.

RETURN VALUES         top

       PAM_AUTH_ERR
           A invalid option was given, the module was not able to
           retrieve the user name, no valid counter file was found, or
           too many failed logins.

       PAM_SUCCESS
           Everything was successful.

       PAM_USER_UNKNOWN
           User not known.

EXAMPLES         top

       Add the following line to /etc/pam.d/login to lock the account
       after too many failed logins. The number of allowed fails is
       specified by /var/log/faillog and needs to be set with pam_tally
       or faillog(8) before.

           auth     required       pam_securetty.so
           auth     required       pam_tally.so per_user
           auth     required       pam_env.so
           auth     required       pam_unix.so
           auth     required       pam_nologin.so
           account  required       pam_unix.so
           password required       pam_unix.so
           session  required       pam_limits.so
           session  required       pam_unix.so
           session  required       pam_lastlog.so nowtmp
           session  optional       pam_mail.so standard

FILES         top

       /var/log/faillog
           failure logging file

SEE ALSO         top

       faillog(8), pam.conf(5), pam.d(5), pam(8)

AUTHOR         top

       pam_tally was written by Tim Baverstock and Tomas Mraz.

COLOPHON         top

       This page is part of the linux-pam (Pluggable Authentication
       Modules for Linux) project.  Information about the project can be
       found at ⟨http://www.linux-pam.org/⟩.  If you have a bug report
       for this manual page, see ⟨//www.linux-pam.org/⟩.  This page was
       obtained from the tarball Linux-PAM-1.3.0.tar.bz2 fetched from
       ⟨http://www.linux-pam.org/library/⟩ on 2020-12-18.  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

Linux-PAM Manual               04/01/2016                   PAM_TALLY(8)