pam_exec(8) — Linux manual page

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

PAM_EXEC(8)                 Linux-PAM Manual                 PAM_EXEC(8)

NAME         top

       pam_exec - PAM module which calls an external command

SYNOPSIS         top


       pam_exec.so [debug] [expose_authtok] [seteuid] [quiet]
                   [quiet_log] [stdout] [log=file] [type=type] command
                   [...]

DESCRIPTION         top

       pam_exec is a PAM module that can be used to run an external
       command.

       The child's environment is set to the current PAM environment
       list, as returned by pam_getenvlist(3) In addition, the following
       PAM items are exported as environment variables: PAM_RHOST,
       PAM_RUSER, PAM_SERVICE, PAM_TTY, PAM_USER and PAM_TYPE, which
       contains one of the module types: account, auth, password,
       open_session and close_session.

       Commands called by pam_exec need to be aware of that the user can
       have control over the environment.

OPTIONS         top

       debug
           Print debug information.

       expose_authtok
           During authentication the calling command can read the
           password from stdin(3). Only first PAM_MAX_RESP_SIZE bytes of
           a password are provided to the command.

       log=file
           The output of the command is appended to file

       type=type
           Only run the command if the module type matches the given
           type.

       stdout
           Per default the output of the executed command is written to
           /dev/null. With this option, the stdout output of the
           executed command is redirected to the calling application.
           It's in the responsibility of this application what happens
           with the output. The log option is ignored.

       quiet
           Per default pam_exec.so will echo the exit status of the
           external command if it fails. Specifying this option will
           suppress the message.

       quiet_log
           Per default pam_exec.so will log the exit status of the
           external command if it fails. Specifying this option will
           suppress the log message.

       seteuid
           Per default pam_exec.so will execute the external command
           with the real user ID of the calling process. Specifying this
           option means the command is run with the effective user ID.

MODULE TYPES PROVIDED         top

       All module types (auth, account, password and session) are
       provided.

RETURN VALUES         top

       PAM_SUCCESS
           The external command was run successfully.

       PAM_BUF_ERR
           Memory buffer error.

       PAM_CONV_ERR
           The conversation method supplied by the application failed to
           obtain the username.

       PAM_INCOMPLETE
           The conversation method supplied by the application returned
           PAM_CONV_AGAIN.

       PAM_SERVICE_ERR
           No argument or a wrong number of arguments were given.

       PAM_SYSTEM_ERR
           A system error occurred or the command to execute failed.

       PAM_IGNORE
           pam_setcred was called, which does not execute the command.
           Or, the value given for the type= parameter did not match the
           module type.

EXAMPLES         top

       Add the following line to /etc/pam.d/passwd to rebuild the NIS
       database after each local password change:

                   password optional pam_exec.so seteuid /usr/bin/make -C /var/yp

       This will execute the command

           make -C /var/yp

       with effective user ID.

SEE ALSO         top

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

AUTHOR         top

       pam_exec was written by Thorsten Kukuk <[email protected]> and
       Josh Triplett <[email protected]>.

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 project's upstream Git repository
       ⟨https://github.com/linux-pam/linux-pam.git⟩ on 2023-12-22.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2023-12-18.)  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
       [email protected]

Linux-PAM Manual               12/22/2023                    PAM_EXEC(8)