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e287086b | 1 | <?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> |
f3bc7fdc | 2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" |
12b42c76 | 3 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
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4 | |
5 | <!-- | |
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6 | SPDX-License-Identifier: LGPL-2.1+ |
7 | ||
f3bc7fdc | 8 | Copyright 2011 Lennart Poettering |
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9 | --> |
10 | ||
dfdebb1b | 11 | <refentry id="systemd-ask-password" |
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12 | xmlns:xi="http://www.w3.org/2001/XInclude"> |
13 | ||
14 | <refentryinfo> | |
15 | <title>systemd-ask-password</title> | |
16 | <productname>systemd</productname> | |
17 | ||
18 | <authorgroup> | |
19 | <author> | |
20 | <contrib>Developer</contrib> | |
21 | <firstname>Lennart</firstname> | |
22 | <surname>Poettering</surname> | |
23 | <email>lennart@poettering.net</email> | |
24 | </author> | |
25 | </authorgroup> | |
26 | </refentryinfo> | |
27 | ||
28 | <refmeta> | |
29 | <refentrytitle>systemd-ask-password</refentrytitle> | |
30 | <manvolnum>1</manvolnum> | |
31 | </refmeta> | |
32 | ||
33 | <refnamediv> | |
34 | <refname>systemd-ask-password</refname> | |
35 | <refpurpose>Query the user for a system password</refpurpose> | |
36 | </refnamediv> | |
37 | ||
38 | <refsynopsisdiv> | |
39 | <cmdsynopsis> | |
40 | <command>systemd-ask-password <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="opt">MESSAGE</arg></command> | |
41 | </cmdsynopsis> | |
42 | </refsynopsisdiv> | |
43 | ||
44 | <refsect1> | |
45 | <title>Description</title> | |
46 | ||
47 | <para><command>systemd-ask-password</command> may be used to query | |
48 | a system password or passphrase from the user, using a question | |
49 | message specified on the command line. When run from a TTY it will | |
50 | query a password on the TTY and print it to standard output. When | |
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51 | run with no TTY or with <option>--no-tty</option> it will use the |
52 | system-wide query mechanism, which allows active users to respond via | |
53 | several agents, listed below.</para> | |
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54 | |
55 | <para>The purpose of this tool is to query system-wide passwords | |
ccddd104 | 56 | — that is passwords not attached to a specific user account. |
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57 | Examples include: unlocking encrypted hard disks when they are |
58 | plugged in or at boot, entering an SSL certificate passphrase for | |
59 | web and VPN servers.</para> | |
60 | ||
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61 | <para>Existing agents are: |
62 | <itemizedlist> | |
63 | ||
64 | <listitem><para>A boot-time password agent asking the user for | |
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65 | passwords using |
66 | <citerefentry project='die-net'><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
67 | </para></listitem> | |
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68 | |
69 | <listitem><para>A boot-time password agent querying the user | |
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70 | directly on the console — |
71 | <citerefentry><refentrytitle>systemd-ask-password-console.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
72 | </para></listitem> | |
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73 | |
74 | <listitem><para>An agent requesting password input via a | |
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75 | <citerefentry project='man-pages'><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry> |
76 | message — | |
77 | <citerefentry><refentrytitle>systemd-ask-password-wall.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, | |
78 | </para></listitem> | |
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79 | |
80 | <listitem><para>A TTY agent that is temporarily spawned during | |
81 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
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82 | invocations,</para></listitem> |
83 | ||
84 | <listitem><para>A command line agent which can be started | |
85 | temporarily to process queued password | |
86 | requests — <command>systemd-tty-ask-password-agent --query</command>. | |
87 | </para></listitem> | |
e287086b | 88 | </itemizedlist></para> |
798d3a52 | 89 | |
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90 | <para>Answering system-wide password queries is a privileged operation, hence |
91 | all the agents listed above (except for the last one), run as privileged | |
92 | system services. The last one also needs elevated privileges, so | |
93 | should be run through | |
94 | <citerefentry project='die-net'><refentrytitle>sudo</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
95 | or similar.</para> | |
96 | ||
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97 | <para>Additional password agents may be implemented according to |
98 | the <ulink | |
28a0ad81 | 99 | url="https://www.freedesktop.org/wiki/Software/systemd/PasswordAgents">systemd |
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100 | Password Agent Specification</ulink>.</para> |
101 | ||
102 | <para>If a password is queried on a TTY, the user may press TAB to | |
103 | hide the asterisks normally shown for each character typed. | |
104 | Pressing Backspace as first key achieves the same effect.</para> | |
105 | ||
106 | </refsect1> | |
107 | ||
108 | <refsect1> | |
109 | <title>Options</title> | |
110 | ||
111 | <para>The following options are understood:</para> | |
112 | ||
113 | <variablelist> | |
114 | <varlistentry> | |
115 | <term><option>--icon=</option></term> | |
116 | ||
117 | <listitem><para>Specify an icon name alongside the password | |
118 | query, which may be used in all agents supporting graphical | |
119 | display. The icon name should follow the <ulink | |
120 | url="http://standards.freedesktop.org/icon-naming-spec/icon-naming-spec-latest.html">XDG | |
121 | Icon Naming Specification</ulink>.</para></listitem> | |
122 | </varlistentry> | |
123 | ||
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124 | <varlistentry> |
125 | <term><option>--id=</option></term> | |
126 | <listitem><para>Specify an identifier for this password | |
127 | query. This identifier is freely choosable and allows | |
128 | recognition of queries by involved agents. It should include | |
129 | the subsystem doing the query and the specific object the | |
130 | query is done for. Example: | |
131 | <literal>--id=cryptsetup:/dev/sda5</literal>.</para></listitem> | |
132 | </varlistentry> | |
133 | ||
134 | <varlistentry> | |
135 | <term><option>--keyname=</option></term> | |
136 | <listitem><para>Configure a kernel keyring key name to use as | |
137 | cache for the password. If set, then the tool will try to push | |
138 | any collected passwords into the kernel keyring of the root | |
139 | user, as a key of the specified name. If combined with | |
b938cb90 | 140 | <option>--accept-cached</option>, it will also try to retrieve |
a8eaaee7 | 141 | such cached passwords from the key in the kernel keyring |
b938cb90 | 142 | instead of querying the user right away. By using this option, |
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143 | the kernel keyring may be used as effective cache to avoid |
144 | repeatedly asking users for passwords, if there are multiple | |
145 | objects that may be unlocked with the same password. The | |
146 | cached key will have a timeout of 2.5min set, after which it | |
147 | will be purged from the kernel keyring. Note that it is | |
148 | possible to cache multiple passwords under the same keyname, | |
149 | in which case they will be stored as NUL-separated list of | |
150 | passwords. Use | |
524f3e5c | 151 | <citerefentry project='die-net'><refentrytitle>keyctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> |
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152 | to access the cached key via the kernel keyring |
153 | directly. Example: <literal>--keyname=cryptsetup</literal></para></listitem> | |
154 | </varlistentry> | |
155 | ||
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156 | <varlistentry> |
157 | <term><option>--timeout=</option></term> | |
158 | ||
159 | <listitem><para>Specify the query timeout in seconds. Defaults | |
160 | to 90s. A timeout of 0 waits indefinitely. </para></listitem> | |
161 | </varlistentry> | |
162 | ||
163 | <varlistentry> | |
164 | <term><option>--echo</option></term> | |
165 | ||
166 | <listitem><para>Echo the user input instead of masking it. | |
167 | This is useful when using | |
168 | <filename>systemd-ask-password</filename> to query for | |
169 | usernames. </para></listitem> | |
170 | </varlistentry> | |
171 | ||
172 | <varlistentry> | |
173 | <term><option>--no-tty</option></term> | |
174 | ||
175 | <listitem><para>Never ask for password on current TTY even if | |
176 | one is available. Always use agent system.</para></listitem> | |
177 | </varlistentry> | |
178 | ||
179 | <varlistentry> | |
180 | <term><option>--accept-cached</option></term> | |
181 | ||
182 | <listitem><para>If passed, accept cached passwords, i.e. | |
a8eaaee7 | 183 | passwords previously entered.</para></listitem> |
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184 | </varlistentry> |
185 | ||
186 | <varlistentry> | |
187 | <term><option>--multiple</option></term> | |
188 | ||
189 | <listitem><para>When used in conjunction with | |
190 | <option>--accept-cached</option> accept multiple passwords. | |
191 | This will output one password per line.</para></listitem> | |
192 | </varlistentry> | |
193 | ||
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194 | <varlistentry> |
195 | <term><option>--no-output</option></term> | |
196 | ||
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197 | <listitem><para>Do not print passwords to standard output. |
198 | This is useful if you want to store a password in kernel | |
199 | keyring with <option>--keyname</option> but do not want it | |
200 | to show up on screen or in logs.</para></listitem> | |
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201 | </varlistentry> |
202 | ||
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203 | <xi:include href="standard-options.xml" xpointer="help" /> |
204 | </variablelist> | |
205 | ||
206 | </refsect1> | |
207 | ||
208 | <refsect1> | |
209 | <title>Exit status</title> | |
210 | ||
211 | <para>On success, 0 is returned, a non-zero failure code | |
212 | otherwise.</para> | |
213 | </refsect1> | |
214 | ||
215 | <refsect1> | |
216 | <title>See Also</title> | |
217 | <para> | |
218 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
c65aafbb | 219 | <citerefentry><refentrytitle>systemd-ask-password-console.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
3f1dc090 | 220 | <citerefentry><refentrytitle>systemd-tty-ask-password-agent</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
524f3e5c | 221 | <citerefentry project='die-net'><refentrytitle>keyctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
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222 | <citerefentry project='die-net'><refentrytitle>plymouth</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
223 | <citerefentry project='man-pages'><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
224 | </para> | |
225 | </refsect1> | |
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226 | |
227 | </refentry> |