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<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><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>

<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><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>