<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> <!-- This file is part of systemd. Copyright 2011 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. --> <refentry id="systemd-ask-password" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>systemd-ask-password</title> <productname>systemd</productname> <authorgroup> <author> <contrib>Developer</contrib> <firstname>Lennart</firstname> <surname>Poettering</surname> <email>lennart@poettering.net</email> </author> </authorgroup> </refentryinfo> <refmeta> <refentrytitle>systemd-ask-password</refentrytitle> <manvolnum>1</manvolnum> </refmeta> <refnamediv> <refname>systemd-ask-password</refname> <refpurpose>Query the user for a system password</refpurpose> </refnamediv> <refsynopsisdiv> <cmdsynopsis> <command>systemd-ask-password <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="opt">MESSAGE</arg></command> </cmdsynopsis> </refsynopsisdiv> <refsect1> <title>Description</title> <para><command>systemd-ask-password</command> 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 <option>--no-tty</option> it will query the password system-wide and allow active users to respond via several agents. The latter is only available to privileged processes.</para> <para>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.</para> <para>Existing agents are: <itemizedlist> <listitem><para>A boot-time password agent asking the user for passwords using Plymouth</para></listitem> <listitem><para>A boot-time password agent querying the user directly on the console</para></listitem> <listitem><para>An agent requesting password input via a <citerefentry project='man-pages'><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry> message</para></listitem> <listitem><para>A command line agent which can be started temporarily to process queued password requests</para></listitem> <listitem><para>A TTY agent that is temporarily spawned during <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> invocations</para></listitem> </itemizedlist></para> <para>Additional password agents may be implemented according to the <ulink url="http://www.freedesktop.org/wiki/Software/systemd/PasswordAgents">systemd Password Agent Specification</ulink>.</para> <para>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.</para> </refsect1> <refsect1> <title>Options</title> <para>The following options are understood:</para> <variablelist> <varlistentry> <term><option>--icon=</option></term> <listitem><para>Specify an icon name alongside the password query, which may be used in all agents supporting graphical display. The icon name should follow the <ulink url="http://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html">XDG Icon Naming Specification</ulink>.</para></listitem> </varlistentry> <varlistentry> <term><option>--id=</option></term> <listitem><para>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: <literal>--id=cryptsetup:/dev/sda5</literal>.</para></listitem> </varlistentry> <varlistentry> <term><option>--keyname=</option></term> <listitem><para>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 <option>--accept-cached</option>, 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 <citerefentry project='die-net'><refentrytitle>keyctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> to access the cached key via the kernel keyring directly. Example: <literal>--keyname=cryptsetup</literal></para></listitem> </varlistentry> <varlistentry> <term><option>--timeout=</option></term> <listitem><para>Specify the query timeout in seconds. Defaults to 90s. A timeout of 0 waits indefinitely. </para></listitem> </varlistentry> <varlistentry> <term><option>--echo</option></term> <listitem><para>Echo the user input instead of masking it. This is useful when using <filename>systemd-ask-password</filename> to query for usernames. </para></listitem> </varlistentry> <varlistentry> <term><option>--no-tty</option></term> <listitem><para>Never ask for password on current TTY even if one is available. Always use agent system.</para></listitem> </varlistentry> <varlistentry> <term><option>--accept-cached</option></term> <listitem><para>If passed, accept cached passwords, i.e. passwords previously entered.</para></listitem> </varlistentry> <varlistentry> <term><option>--multiple</option></term> <listitem><para>When used in conjunction with <option>--accept-cached</option> accept multiple passwords. This will output one password per line.</para></listitem> </varlistentry> <varlistentry> <term><option>--no-output</option></term> <listitem><para>Do not print passwords to standard output. This is useful if you want to store a password in kernel keyring with <option>--keyname</option> but do not want it to show up on screen or in logs.</para></listitem> </varlistentry> <xi:include href="standard-options.xml" xpointer="help" /> </variablelist> </refsect1> <refsect1> <title>Exit status</title> <para>On success, 0 is returned, a non-zero failure code otherwise.</para> </refsect1> <refsect1> <title>See Also</title> <para> <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry project='die-net'><refentrytitle>keyctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry project='die-net'><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>, <citerefentry project='man-pages'><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry> </para> </refsect1> </refentry>