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

PAM_TALLY2(8)                 Linux-PAM Manual                 PAM_TALLY2(8)

NAME         top

       pam_tally2 - The login counter (tallying) module

SYNOPSIS         top

       pam_tally2.so [file=/path/to/counter] [onerr=[fail|succeed]]
                     [magic_root] [even_deny_root] [deny=n] [lock_time=n]
                     [unlock_time=n] [root_unlock_time=n] [serialize]
                     [audit] [silent] [no_log_info] [debug]

       pam_tally2 [--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_tally2 comes in two parts: pam_tally2.so and pam_tally2. The
       former is the PAM module and the latter, a stand-alone program.
       pam_tally2 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.

       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/tallylog.

           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).

           debug
               Always log tally count when it is incremented as a debug
               level message to the system log.

       AUTH OPTIONS
           Authentication phase first increments attempted login counter and
           checks if user should be denied access. If the user is
           authenticated and the login process continues 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.

           even_deny_root
               Root account can become unavailable.

           root_unlock_time=n
               This option implies even_deny_root option. Allow access after
               n seconds to root account after failed attempt. If this
               option is used the root user will be locked out for the
               specified amount of time after he exceeded his maximum
               allowed attempts.

           serialize
               Serialize access to the tally file using locks. This option
               might be used only for non-multithreaded services because it
               depends on the fcntl locking of the tally file. Also it is a
               good idea to use this option only in such configurations
               where the time between auth phase and account or setcred
               phase is not dependent on the authenticating client.
               Otherwise the authenticating client will be able to prevent
               simultaneous authentications by the same user by simply
               artificially prolonging the time the file record lock is
               held.

       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 changed. The sysadmin should use this for user launched
               services, like su, otherwise this argument should be omitted.

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.

NOTES         top

       pam_tally2 is not compatible with the old pam_tally faillog file
       format. This is caused by requirement of compatibility of the
       tallylog file format between 32bit and 64bit architectures on
       multiarch systems.

       There is no setuid wrapper for access to the data file such as when
       the pam_tally2.so module is called from xscreensaver. As this would
       make it impossible to share PAM configuration with such services the
       following workaround is used: If the data file cannot be opened
       because of insufficient permissions (EACCES) the module returns
       PAM_IGNORE.

EXAMPLES         top

       Add the following line to /etc/pam.d/login to lock the account after
       4 failed logins. Root account will be locked as well. The accounts
       will be automatically unlocked after 20 minutes. The module does not
       have to be called in the account phase because the login calls
       pam_setcred(3) correctly.

           auth     required       pam_securetty.so
           auth     required       pam_tally2.so deny=4 even_deny_root unlock_time=1200
           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/tallylog
           failure count logging file

SEE ALSO         top

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

AUTHOR         top

       pam_tally2 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.gz fetched from 
       ⟨http://www.linux-pam.org/library/⟩ on 2017-07-05.  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_TALLY2(8)