152
127
</refsynopsisdiv>
154
129
<refsect1 id="description">
155
130
<title>DESCRIPTION</title>
157
<command>&COMMANDNAME;</command> is a program which is meant to
158
be specified as a <quote>keyscript</quote> for the root disk in
132
<command>&COMMANDNAME;</command> is a plugin runner that waits
133
for any of its plugins to return sucessfull with a password, and
134
passes it to cryptsetup as stdout message. This command is not
135
meant to be invoked directly, but is instead meant to be run by
136
cryptsetup by being specified in /etc/crypttab as a keyscript
137
and subsequlently started in the initrd environment. See
159
138
<citerefentry><refentrytitle>crypttab</refentrytitle>
160
<manvolnum>5</manvolnum></citerefentry>. The aim of this
161
program is therefore to output a password, which then
162
<citerefentry><refentrytitle>cryptsetup</refentrytitle>
163
<manvolnum>8</manvolnum></citerefentry> will use to unlock the
167
This program is not meant to be invoked directly, but can be in
168
order to test it. Note that any password obtained will simply
169
be output on standard output.
173
<refsect1 id="purpose">
174
<title>PURPOSE</title>
176
The purpose of this is to enable <emphasis>remote and unattended
177
rebooting</emphasis> of client host computer with an
178
<emphasis>encrypted root file system</emphasis>. See <xref
179
linkend="overview"/> for details.
139
<manvolnum>5</manvolnum></citerefentry> for more information on
144
plugins is looked for in the plugins directory which by default will be
145
/conf/conf.d/mandos/plugins.d if not changed by option --plugin-dir.
184
149
<title>OPTIONS</title>
187
<term><option>--global-env
188
<replaceable>ENV</replaceable><literal>=</literal><replaceable
189
>value</replaceable></option></term>
191
<replaceable>ENV</replaceable><literal>=</literal><replaceable
192
>value</replaceable></option></term>
195
This option will add an environment variable setting to
196
all plugins. This will override any inherited environment
203
<term><option>--env-for
204
<replaceable>PLUGIN</replaceable><literal>:</literal
205
><replaceable>ENV</replaceable><literal>=</literal
206
><replaceable>value</replaceable></option></term>
208
<replaceable>PLUGIN</replaceable><literal>:</literal
209
><replaceable>ENV</replaceable><literal>=</literal
210
><replaceable>value</replaceable></option></term>
213
This option will add an environment variable setting to
214
the <replaceable>PLUGIN</replaceable> plugin. This will
215
override any inherited environment variables or
216
environment variables specified using
217
<option>--global-env</option>.
223
152
<term><option>--global-options
224
153
<replaceable>OPTIONS</replaceable></option></term>
226
155
<replaceable>OPTIONS</replaceable></option></term>
229
Pass some options to <emphasis>all</emphasis> plugins.
230
<replaceable>OPTIONS</replaceable> is a comma separated
231
list of options. This is not a very useful option, except
232
for specifying the <quote><option>--debug</option></quote>
233
option to all plugins.
158
Global options given to all plugins as additional start
159
arguments. Options are specified with a -o flag followed
160
by a comma separated string of options.
239
166
<term><option>--options-for
240
167
<replaceable>PLUGIN</replaceable><literal>:</literal
244
171
><replaceable>OPTION</replaceable></option></term>
247
Pass some options to a specific plugin. <replaceable
248
>PLUGIN</replaceable> is the name (file basename) of a
249
plugin, and <replaceable>OPTIONS</replaceable> is a comma
250
separated list of options.
253
Note that since options are not split on whitespace, the
254
way to pass, to the plugin
255
<quote><filename>foo</filename></quote>, the option
256
<option>--bar</option> with the option argument
257
<quote>baz</quote> is either
258
<userinput>--options-for=foo:--bar=baz</userinput> or
259
<userinput>--options-for=foo:--bar,baz</userinput>. Using
260
<userinput>--options-for="foo:--bar baz"</userinput>. will
261
<emphasis>not</emphasis> work.
174
Plugin specific options given to the plugin as additional
175
start arguments. Options are specified with a -o flag
176
followed by a comma separated string of options.
267
<term><option>--disable
182
<term><option> --disable
268
183
<replaceable>PLUGIN</replaceable></option></term>
270
185
<replaceable>PLUGIN</replaceable></option></term>
273
Disable the plugin named
274
<replaceable>PLUGIN</replaceable>. The plugin will not be
281
<term><option>--enable
282
<replaceable>PLUGIN</replaceable></option></term>
284
<replaceable>PLUGIN</replaceable></option></term>
287
Re-enable the plugin named
288
<replaceable>PLUGIN</replaceable>. This is only useful to
289
undo a previous <option>--disable</option> option, maybe
290
from the configuration file.
188
Disable a specific plugin
296
194
<term><option>--groupid
297
195
<replaceable>ID</replaceable></option></term>
300
Change to group ID <replaceable>ID</replaceable> on
301
startup. The default is 65534. All plugins will be
302
started using this group ID. <emphasis>Note:</emphasis>
303
This must be a number, not a name.
198
Group ID the plugins will run as
309
204
<term><option>--userid
310
205
<replaceable>ID</replaceable></option></term>
313
Change to user ID <replaceable>ID</replaceable> on
314
startup. The default is 65534. All plugins will be
315
started using this user ID. <emphasis>Note:</emphasis>
316
This must be a number, not a name.
208
User ID the plugins will run as
322
214
<term><option>--plugin-dir
323
215
<replaceable>DIRECTORY</replaceable></option></term>
326
Specify a different plugin directory. The default is
327
<filename>/lib/mandos/plugins.d</filename>, which will
328
exist in the initial <acronym>RAM</acronym> disk
335
<term><option>--plugin-helper-dir
336
<replaceable>DIRECTORY</replaceable></option></term>
339
Specify a different plugin helper directory. The default
340
is <filename>/lib/mandos/plugin-helpers</filename>, which
341
will exist in the initial <acronym>RAM</acronym> disk
342
environment. (This will simply be passed to all plugins
343
via the <envar>MANDOSPLUGINHELPERDIR</envar> environment
344
variable. See <xref linkend="writing_plugins"/>)
350
<term><option>--config-file
351
<replaceable>FILE</replaceable></option></term>
354
Specify a different file to read additional options from.
355
See <xref linkend="files"/>. Other command line options
356
will override options specified in the file.
218
Specify a different plugin directory
391
243
<term><option>--usage</option></term>
394
Gives a short usage message.
246
Gives a short usage message
400
252
<term><option>--version</option></term>
401
253
<term><option>-V</option></term>
404
Prints the program version.
256
Prints the program version
411
<refsect1 id="overview">
412
<title>OVERVIEW</title>
413
<xi:include href="overview.xml"/>
415
This program will run on the client side in the initial
416
<acronym>RAM</acronym> disk environment, and is responsible for
417
getting a password. It does this by running plugins, one of
418
which will normally be the actual client program communicating
422
<refsect1 id="plugins">
423
<title>PLUGINS</title>
425
This program will get a password by running a number of
426
<firstterm>plugins</firstterm>, which are executable programs in
427
a directory in the initial <acronym>RAM</acronym> disk
428
environment. The default directory is
429
<filename>/lib/mandos/plugins.d</filename>, but this can be
430
changed with the <option>--plugin-dir</option> option. The
431
plugins are started in parallel, and the first plugin to output
432
a password <emphasis>and</emphasis> exit with a successful exit
433
code will make this plugin-runner output the password from that
434
plugin, stop any other plugins, and exit.
437
<refsect2 id="writing_plugins">
438
<title>WRITING PLUGINS</title>
440
A plugin is an executable program which prints a password to
441
its standard output and then exits with a successful (zero)
442
exit status. If the exit status is not zero, any output on
443
standard output will be ignored by the plugin runner. Any
444
output on its standard error channel will simply be passed to
445
the standard error of the plugin runner, usually the system
449
If the password is a single-line, manually entered passprase,
450
a final trailing newline character should
451
<emphasis>not</emphasis> be printed.
454
The plugin will run in the initial RAM disk environment, so
455
care must be taken not to depend on any files or running
456
services not available there. Any helper executables required
457
by the plugin (which are not in the <envar>PATH</envar>) can
458
be placed in the plugin helper directory, the name of which
459
will be made available to the plugin via the
460
<envar>MANDOSPLUGINHELPERDIR</envar> environment variable.
463
The plugin must exit cleanly and free all allocated resources
464
upon getting the TERM signal, since this is what the plugin
465
runner uses to stop all other plugins when one plugin has
466
output a password and exited cleanly.
469
The plugin must not use resources, like for instance reading
470
from the standard input, without knowing that no other plugin
474
It is useful, but not required, for the plugin to take the
475
<option>--debug</option> option.
480
<refsect1 id="fallback">
481
<title>FALLBACK</title>
483
If no plugins succeed, this program will, as a fallback, ask for
484
a password on the console using <citerefentry><refentrytitle
485
>getpass</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
486
and output it. This is not meant to be the normal mode of
487
operation, as there is a separate plugin for getting a password
492
263
<refsect1 id="exit_status">
493
264
<title>EXIT STATUS</title>
495
Exit status of this program is zero if no errors were
496
encountered, and otherwise not. The fallback (see <xref
497
linkend="fallback"/>) may or may not have succeeded in either
502
<refsect1 id="environment">
503
<title>ENVIRONMENT</title>
505
This program does not use any environment variables itself, it
506
only passes on its environment to all the plugins. The
507
environment passed to plugins can be modified using the
508
<option>--global-env</option> and <option>--env-for</option>
509
options. Also, the <option>--plugin-helper-dir</option> option
510
will affect the environment variable
511
<envar>MANDOSPLUGINHELPERDIR</envar> for the plugins.
515
<refsect1 id="files">
516
270
<title>FILES</title>
521
>/conf/conf.d/mandos/plugin-runner.conf</filename></term>
524
Since this program will be run as a keyscript, there is
525
little to no opportunity to pass command line arguments
526
to it. Therefore, it will <emphasis>also</emphasis>
527
read this file and use its contents as
528
whitespace-separated command line options. Also,
529
everything from a <quote>#</quote> character to the end
530
of a line is ignored.
533
This program is meant to run in the initial RAM disk
534
environment, so that is where this file is assumed to
535
exist. The file does not need to exist in the normal
539
This file will be processed <emphasis>before</emphasis>
540
the normal command line options, so the latter can
541
override the former, if need be.
544
This file name is the default; the file to read for
545
arguments can be changed using the
546
<option>--config-file</option> option.
551
<term><filename class="directory"
552
>/lib/mandos/plugins.d</filename></term>
555
The default plugin directory; can be changed by the
556
<option>--plugin-dir</option> option.
561
<term><filename class="directory"
562
>/lib/mandos/plugin-helpers</filename></term>
565
The default plugin helper directory; can be changed by
566
the <option>--plugin-helper-dir</option> option.
275
<refsect1 id="notes">
574
281
<refsect1 id="bugs">
575
282
<title>BUGS</title>
577
The <option>--config-file</option> option is ignored when
578
specified from within a configuration file.
580
<xi:include href="bugs.xml"/>
583
287
<refsect1 id="examples">
584
288
<title>EXAMPLE</title>
587
Normal invocation needs no options:
590
<userinput>&COMMANDNAME;</userinput>
595
Run the program, but not the plugins, in debug mode:
599
<!-- do not wrap this line -->
600
<userinput>&COMMANDNAME; --debug</userinput>
606
Run all plugins, but run the <quote>foo</quote> plugin in
611
<!-- do not wrap this line -->
612
<userinput>&COMMANDNAME; --options-for=foo:--debug</userinput>
618
Run all plugins, but not the program, in debug mode:
622
<!-- do not wrap this line -->
623
<userinput>&COMMANDNAME; --global-options=--debug</userinput>
629
Read a different configuration file, run plugins from a
630
different directory, specify an alternate plugin helper
631
directory and add four options to the
632
<citerefentry><refentrytitle >mandos-client</refentrytitle>
633
<manvolnum>8mandos</manvolnum></citerefentry> plugin:
637
<!-- do not wrap this line -->
638
<userinput>cd /etc/keys/mandos; &COMMANDNAME; --config-file=/etc/mandos/plugin-runner.conf --plugin-dir /usr/lib/x86_64-linux-gnu/mandos/plugins.d --plugin-helper-dir /usr/lib/x86_64-linux-gnu/mandos/plugin-helpers --options-for=mandos-client:--pubkey=pubkey.txt,​--seckey=seckey.txt,​--tls-pubkey=tls-pubkey.pem,​--tls-privkey=tls-privkey.pem</userinput>
643
293
<refsect1 id="security">
644
294
<title>SECURITY</title>
646
This program will, when starting, try to switch to another user.
647
If it is started as root, it will succeed, and will by default
648
switch to user and group 65534, which are assumed to be
649
non-privileged. This user and group is then what all plugins
650
will be started as. Therefore, the only way to run a plugin as
651
a privileged user is to have the set-user-ID or set-group-ID bit
652
set on the plugin executable file (see <citerefentry>
653
<refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum>
657
If this program is used as a keyscript in <citerefentry
658
><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum>
659
</citerefentry>, there is a slight risk that if this program
660
fails to work, there might be no way to boot the system except
661
for booting from another media and editing the initial RAM disk
662
image to not run this program. This is, however, unlikely,
663
since the <citerefentry><refentrytitle
664
>password-prompt</refentrytitle><manvolnum>8mandos</manvolnum>
665
</citerefentry> plugin will read a password from the console in
666
case of failure of the other plugins, and this plugin runner
667
will also, in case of catastrophic failure, itself fall back to
668
asking and outputting a password on the console (see <xref
669
linkend="fallback"/>).
673
299
<refsect1 id="see_also">
674
300
<title>SEE ALSO</title>
676
<citerefentry><refentrytitle>intro</refentrytitle>
677
<manvolnum>8mandos</manvolnum></citerefentry>,
678
302
<citerefentry><refentrytitle>cryptsetup</refentrytitle>
679
303
<manvolnum>8</manvolnum></citerefentry>,
680
<citerefentry><refentrytitle>crypttab</refentrytitle>
681
<manvolnum>5</manvolnum></citerefentry>,
682
<citerefentry><refentrytitle>execve</refentrytitle>
683
<manvolnum>2</manvolnum></citerefentry>,
684
304
<citerefentry><refentrytitle>mandos</refentrytitle>
685
305
<manvolnum>8</manvolnum></citerefentry>,
686
306
<citerefentry><refentrytitle>password-prompt</refentrytitle>
687
307
<manvolnum>8mandos</manvolnum></citerefentry>,
688
<citerefentry><refentrytitle>mandos-client</refentrytitle>
308
<citerefentry><refentrytitle>password-request</refentrytitle>
689
309
<manvolnum>8mandos</manvolnum></citerefentry>
694
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