− Query the user for a system 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 query the
password system−wide and allow active users to respond
via several agents. The latter is only available to
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.
boot−time password agent asking the user for passwords
boot−time password agent querying the user directly on
• An agent
requesting password input via a wall(1) message
command line agent which can be started temporarily to
process queued password requests
• A TTY
agent that is temporarily spawned during systemctl(1)
password agents may be implemented according to the
systemd Password Agent
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
following options are understood:
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
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.
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.
the query timeout in seconds. Defaults to 90s. A timeout of
0 waits indefinitely.
user input instead of masking it. This is useful when using
systemd−ask−password to query for
for password on current TTY even if one is available. Always
use agent system.
passed, accept cached passwords, i.e. passwords previously
in conjunction with −−accept−cached
accept multiple passwords. This will output one password per
short help text and exit.
success, 0 is returned, a non−zero failure code
systemctl(1), keyctl(1), plymouth(8),
Password Agent Specification