NAME

       systemd-ask-password - Query the user for a system password

SYNOPSIS

       systemd-ask-password [OPTIONS...] [MESSAGE]

DESCRIPTION

       systemd-ask-password may be used to query a system password or passphrase from the user,
       using a question message specified on the command line. When run from a TTY it will query
       a password on the TTY and print it to standard output. When run with no TTY or with
       --no-tty it will use the system-wide query mechanism, which allows active users to respond
       via several agents, listed below.

       The purpose of this tool is to query system-wide passwords — that is passwords not
       attached to a specific user account. Examples include: unlocking encrypted hard disks when
       they are plugged in or at boot, entering an SSL certificate passphrase for web and VPN
       servers.

       Existing agents are:

       •   A boot-time password agent asking the user for passwords using plymouth(8),

       •   A boot-time password agent querying the user directly on the console — systemd-ask-
           password-console.service(8),

       •   An agent requesting password input via a wall(1) message — systemd-ask-password-
           wall.service(8),

       •   A TTY agent that is temporarily spawned during systemctl(1) invocations,

       •   A command line agent which can be started temporarily to process queued password
           requests — systemd-tty-ask-password-agent --query.

       Answering system-wide password queries is a privileged operation, hence all the agents
       listed above (except for the last one), run as privileged system services. The last one
       also needs elevated privileges, so should be run through sudo(8) or similar.

       Additional password agents may be implemented according to the systemd Password Agent
       Specification[1].

       If a password is queried on a TTY, the user may press TAB to hide the asterisks normally
       shown for each character typed. Pressing Backspace as first key achieves the same effect.

OPTIONS

       The following options are understood:

       --icon=
           Specify an icon name alongside the password query, which may be used in all agents
           supporting graphical display. The icon name should follow the XDG Icon Naming
           Specification[2].

       --id=
           Specify an identifier for this password query. This identifier is freely choosable and
           allows recognition of queries by involved agents. It should include the subsystem
           doing the query and the specific object the query is done for. Example:
           "--id=cryptsetup:/dev/sda5".

           Added in version 227.

       --keyname=
           Configure a kernel keyring key name to use as cache for the password. If set, then the
           tool will try to push any collected passwords into the kernel keyring of the root
           user, as a key of the specified name. If combined with --accept-cached, it will also
           try to retrieve such cached passwords from the key in the kernel keyring instead of
           querying the user right away. By using this option, the kernel keyring may be used as
           effective cache to avoid repeatedly asking users for passwords, if there are multiple
           objects that may be unlocked with the same password. The cached key will have a
           timeout of 2.5min set, after which it will be purged from the kernel keyring. Note
           that it is possible to cache multiple passwords under the same keyname, in which case
           they will be stored as NUL-separated list of passwords. Use keyctl(1) to access the
           cached key via the kernel keyring directly. Example: "--keyname=cryptsetup"

           Added in version 227.

       --credential=
           Configure a credential to read the password from – if it exists. This may be used in
           conjunction with the ImportCredential=, LoadCredential= and SetCredential= settings in
           unit files. See systemd.exec(5) for details. If not specified, defaults to "password".
           This option has no effect if no credentials directory is passed to the program (i.e.
           $CREDENTIALS_DIRECTORY is not set) or if the no credential of the specified name
           exists.

           Added in version 249.

       --timeout=
           Specify the query timeout in seconds. Defaults to 90s. A timeout of 0 waits
           indefinitely.

       --echo=yes|no|masked
           Controls whether to echo user input. Takes a boolean or the special string "masked",
           the default being the latter. If enabled the typed characters are echoed literally,
           which is useful for prompting for usernames and other non-protected data. If disabled
           the typed characters are not echoed in any form, the user will not get feedback on
           their input. If set to "masked", an asterisk ("*") is echoed for each character typed.
           In this mode, if the user hits the tabulator key ("↹"), echo is turned off.
           (Alternatively, if the user hits the backspace key ("⌫") while no data has been
           entered otherwise, echo is turned off, too).

           Added in version 249.

       --echo, -e
           Equivalent to --echo=yes, see above.

           Added in version 217.

       --emoji=yes|no|auto
           Controls whether or not to prefix the query with a lock and key emoji (🔐), if the TTY
           settings permit this. The default is "auto", which defaults to "yes", unless
           --echo=yes is given.

           Added in version 249.

       --no-tty
           Never ask for password on current TTY even if one is available. Always use agent
           system.

       --accept-cached
           If passed, accept cached passwords, i.e. passwords previously entered.

       --multiple
           When used in conjunction with --accept-cached accept multiple passwords. This will
           output one password per line.

       --no-output
           Do not print passwords to standard output. This is useful if you want to store a
           password in kernel keyring with --keyname= but do not want it to show up on screen or
           in logs.

           Added in version 230.

       -n
           By default, when the acquired password is written to standard output it is suffixed by
           a newline character. This may be turned off with the -n switch, similarly to the
           switch of the same name of the echo(1) command.

           Added in version 249.

       -h, --help
           Print a short help text and exit.

EXIT STATUS

       On success, 0 is returned, a non-zero failure code otherwise.

SEE ALSO

       systemd(1), systemd-ask-password-console.service(8), systemd-tty-ask-password-agent(1),
       keyctl(1), plymouth(8), wall(1)

NOTES

        1. systemd Password Agent Specification
           https://systemd.io/PASSWORD_AGENTS/

        2. XDG Icon Naming Specification
           https://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html