NAME

       pam_tally2 - The login counter (tallying) module

SYNOPSIS

       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]

       pam_tally2 [--file /path/to/counter] [--user username] [--reset[=n]] [--quiet]

DESCRIPTION

       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 users' 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

       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).

       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

       The auth and account module types are provided.

RETURN VALUES

       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

       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

       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

       /var/log/tallylog
           failure count logging file

SEE ALSO

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

AUTHOR

       pam_tally2 was written by Tim Baverstock and Tomas Mraz.