pam_systemd_home(8) — Linux manual page


PAM_SYSTEMD_HOME(8)           pam_systemd_home           PAM_SYSTEMD_HOME(8)

NAME         top

       pam_systemd_home - Automatically mount home directories managed by
       systemd-homed.service on login, and unmount them on logout

SYNOPSIS         top

DESCRIPTION         top

       pam_systemd_home ensures that home directories managed by
       systemd-homed.service(8) are automatically activated (mounted) on
       user login, and are deactivated (unmounted) when the last session of
       the user ends.

OPTIONS         top

       The following options are understood:

           Takes a boolean argument. If true, the home directory of the user
           will be suspended automatically during system suspend; if false
           it will remain active. Automatic suspending of the home directory
           improves security substantially as secret key material is
           automatically removed from memory before the system is put to
           sleep and must be re-acquired (through user re-authentication)
           when coming back from suspend. It is recommended to set this
           parameter for all PAM applications that have support for
           automatically re-authenticating via PAM on system resume. If
           multiple sessions of the same user are open in parallel the
           user's home directory will be left unsuspended on system suspend
           as long as at least one of the sessions does not set this
           parameter to on. Defaults to off.

           Note that TTY logins generally do not support re-authentication
           on system resume. Re-authentication on system resume is primarily
           a concept implementable in graphical environments, in the form of
           lock screens brought up automatically when the system goes to
           sleep. This means that if a user concurrently uses graphical
           login sessions that implement the required re-authentication
           mechanism and console logins that do not, the home directory is
           not locked during suspend, due to the logic explained above. That
           said, it is possible to set this field for TTY logins too,
           ignoring the fact that TTY logins actually don't support the
           re-authentication mechanism. In that case the TTY sessions will
           appear hung until the user logs in on another virtual terminal
           (regardless if via another TTY session or graphically) which will
           resume the home directory and unblock the original TTY session.
           (Do note that lack of screen locking on TTY sessions means even
           though the TTY session appears hung, keypresses can still be
           queued into it, and the existing screen contents be read without
           re-authentication; this limitation is unrelated to the home
           directory management pam_systemd_home and systemd-homed.service

           Turning this option on by default is highly recommended for all
           sessions, but only if the service managing these sessions
           correctly implements the aforementioned re-authentication. Note
           that the re-authentication must take place from a component
           running outside of the user's context, so that it does not
           require access to the user's home directory for operation.
           Traditionally, most desktop environments do not implement screen
           locking this way, and need to be updated accordingly.

           This setting may also be controlled via the $SYSTEMD_HOME_SUSPEND
           environment variable (see below), which pam_systemd_home reads
           during initialization and sets for sessions. If both the
           environment variable is set and the module parameter specified
           the latter takes precedence.

           Takes an optional boolean argument. If yes or without the
           argument, the module will log debugging information as it


       The module provides all four management operations: auth, account,
       session, password.

ENVIRONMENT         top

       The following environment variables are initialized by the module and
       available to the processes of the user's session:

           Indicates that the user's home directory is managed by

           Indicates whether the session has been registered with the
           suspend mechanism enabled or disabled (see above). The variable's
           value is either "0" or "1". Note that the module both reads the
           variable when initializing, and sets it for sessions.

EXAMPLE         top

       Here's an example PAM configuration fragment that permits users
       managed by systemd-homed.service to log in:

           auth      sufficient
           -auth     sufficient
           auth      required

           account   required
           -account  sufficient
           account   sufficient
           account   required

           -password sufficient
           password  sufficient sha512 shadow try_first_pass try_authtok
           password  required

           -session  optional revoke
           -session  optional
           -session  optional
           -session  optional
           session   required

SEE ALSO         top

       systemd(1), systemd-homed.service(8), homed.conf(5), homectl(1),
       pam_systemd(8), pam.conf(5), pam.d(5), pam(8)

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug
       report for this manual page, see
       ⟨⟩.  This
       page was obtained from the project's upstream Git repository
       ⟨⟩ on 2020-09-18.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-09-18.)  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
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       of the original manual page), send a mail to

systemd 246                                              PAM_SYSTEMD_HOME(8)

Pages that refer to this page: 30-systemd-environment-d-generator(7)systemd.directives(7)systemd.index(7)pam_systemd(8)systemd-homed(8)systemd-homed.service(8)