150
127
</refsynopsisdiv>
152
129
<refsect1 id="description">
153
130
<title>DESCRIPTION</title>
155
<command>&COMMANDNAME;</command> is a program which is meant to
156
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
157
138
<citerefentry><refentrytitle>crypttab</refentrytitle>
158
<manvolnum>5</manvolnum></citerefentry>. The aim of this
159
program is therefore to output a password, which then
160
<citerefentry><refentrytitle>cryptsetup</refentrytitle>
161
<manvolnum>8</manvolnum></citerefentry> will use to unlock the
165
This program is not meant to be invoked directly, but can be in
166
order to test it. Note that any password obtained will simply
167
be output on standard output.
171
<refsect1 id="purpose">
172
<title>PURPOSE</title>
174
The purpose of this is to enable <emphasis>remote and unattended
175
rebooting</emphasis> of client host computer with an
176
<emphasis>encrypted root file system</emphasis>. See <xref
177
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.
182
149
<title>OPTIONS</title>
185
<term><option>--global-env
186
<replaceable>ENV</replaceable><literal>=</literal><replaceable
187
>value</replaceable></option></term>
189
<replaceable>ENV</replaceable><literal>=</literal><replaceable
190
>value</replaceable></option></term>
193
This option will add an environment variable setting to
194
all plugins. This will override any inherited environment
201
<term><option>--env-for
202
<replaceable>PLUGIN</replaceable><literal>:</literal
203
><replaceable>ENV</replaceable><literal>=</literal
204
><replaceable>value</replaceable></option></term>
206
<replaceable>PLUGIN</replaceable><literal>:</literal
207
><replaceable>ENV</replaceable><literal>=</literal
208
><replaceable>value</replaceable></option></term>
211
This option will add an environment variable setting to
212
the <replaceable>PLUGIN</replaceable> plugin. This will
213
override any inherited environment variables or
214
environment variables specified using
215
<option>--global-env</option>.
221
152
<term><option>--global-options
222
153
<replaceable>OPTIONS</replaceable></option></term>
224
155
<replaceable>OPTIONS</replaceable></option></term>
227
Pass some options to <emphasis>all</emphasis> plugins.
228
<replaceable>OPTIONS</replaceable> is a comma separated
229
list of options. This is not a very useful option, except
230
for specifying the <quote><option>--debug</option></quote>
231
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.
237
166
<term><option>--options-for
238
167
<replaceable>PLUGIN</replaceable><literal>:</literal
242
171
><replaceable>OPTION</replaceable></option></term>
245
Pass some options to a specific plugin. <replaceable
246
>PLUGIN</replaceable> is the name (file basename) of a
247
plugin, and <replaceable>OPTIONS</replaceable> is a comma
248
separated list of options.
251
Note that since options are not split on whitespace, the
252
way to pass, to the plugin
253
<quote><filename>foo</filename></quote>, the option
254
<option>--bar</option> with the option argument
255
<quote>baz</quote> is either
256
<userinput>--options-for=foo:--bar=baz</userinput> or
257
<userinput>--options-for=foo:--bar,baz</userinput>. Using
258
<userinput>--options-for="foo:--bar baz"</userinput>. will
259
<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.
265
<term><option>--disable
182
<term><option> --disable
266
183
<replaceable>PLUGIN</replaceable></option></term>
268
185
<replaceable>PLUGIN</replaceable></option></term>
271
Disable the plugin named
272
<replaceable>PLUGIN</replaceable>. The plugin will not be
279
<term><option>--enable
280
<replaceable>PLUGIN</replaceable></option></term>
282
<replaceable>PLUGIN</replaceable></option></term>
285
Re-enable the plugin named
286
<replaceable>PLUGIN</replaceable>. This is only useful to
287
undo a previous <option>--disable</option> option, maybe
288
from the configuration file.
188
Disable a specific plugin
294
194
<term><option>--groupid
295
195
<replaceable>ID</replaceable></option></term>
298
Change to group ID <replaceable>ID</replaceable> on
299
startup. The default is 65534. All plugins will be
300
started using this group ID. <emphasis>Note:</emphasis>
301
This must be a number, not a name.
198
Group ID the plugins will run as
307
204
<term><option>--userid
308
205
<replaceable>ID</replaceable></option></term>
311
Change to user ID <replaceable>ID</replaceable> on
312
startup. The default is 65534. All plugins will be
313
started using this user ID. <emphasis>Note:</emphasis>
314
This must be a number, not a name.
208
User ID the plugins will run as
320
214
<term><option>--plugin-dir
321
215
<replaceable>DIRECTORY</replaceable></option></term>
324
Specify a different plugin directory. The default is
325
<filename>/lib/mandos/plugins.d</filename>, which will
326
exist in the initial <acronym>RAM</acronym> disk
333
<term><option>--plugin-helper-dir
334
<replaceable>DIRECTORY</replaceable></option></term>
337
Specify a different plugin helper directory. The default
338
is <filename>/lib/mandos/plugin-helpers</filename>, which
339
will exist in the initial <acronym>RAM</acronym> disk
340
environment. (This will simply be passed to all plugins
341
via the <envar>MANDOSPLUGINHELPERDIR</envar> environment
342
variable. See <xref linkend="writing_plugins"/>)
348
<term><option>--config-file
349
<replaceable>FILE</replaceable></option></term>
352
Specify a different file to read additional options from.
353
See <xref linkend="files"/>. Other command line options
354
will override options specified in the file.
218
Specify a different plugin directory
389
243
<term><option>--usage</option></term>
392
Gives a short usage message.
246
Gives a short usage message
398
252
<term><option>--version</option></term>
399
253
<term><option>-V</option></term>
402
Prints the program version.
256
Prints the program version
409
<refsect1 id="overview">
410
<title>OVERVIEW</title>
411
<xi:include href="overview.xml"/>
413
This program will run on the client side in the initial
414
<acronym>RAM</acronym> disk environment, and is responsible for
415
getting a password. It does this by running plugins, one of
416
which will normally be the actual client program communicating
420
<refsect1 id="plugins">
421
<title>PLUGINS</title>
423
This program will get a password by running a number of
424
<firstterm>plugins</firstterm>, which are simply executable
425
programs in a directory in the initial <acronym>RAM</acronym>
426
disk environment. The default directory is
427
<filename>/lib/mandos/plugins.d</filename>, but this can be
428
changed with the <option>--plugin-dir</option> option. The
429
plugins are started in parallel, and the first plugin to output
430
a password <emphasis>and</emphasis> exit with a successful exit
431
code will make this plugin-runner output the password from that
432
plugin, stop any other plugins, and exit.
435
<refsect2 id="writing_plugins">
436
<title>WRITING PLUGINS</title>
438
A plugin is simply a program which prints a password to its
439
standard output and then exits with a successful (zero) exit
440
status. If the exit status is not zero, any output on
441
standard output will be ignored by the plugin runner. Any
442
output on its standard error channel will simply be passed to
443
the standard error of the plugin runner, usually the system
447
If the password is a single-line, manually entered passprase,
448
a final trailing newline character should
449
<emphasis>not</emphasis> be printed.
452
The plugin will run in the initial RAM disk environment, so
453
care must be taken not to depend on any files or running
454
services not available there. Any helper executables required
455
by the plugin (which are not in the <envar>PATH</envar>) can
456
be placed in the plugin helper directory, the name of which
457
will be made available to the plugin via the
458
<envar>MANDOSPLUGINHELPERDIR</envar> environment variable.
461
The plugin must exit cleanly and free all allocated resources
462
upon getting the TERM signal, since this is what the plugin
463
runner uses to stop all other plugins when one plugin has
464
output a password and exited cleanly.
467
The plugin must not use resources, like for instance reading
468
from the standard input, without knowing that no other plugin
472
It is useful, but not required, for the plugin to take the
473
<option>--debug</option> option.
478
<refsect1 id="fallback">
479
<title>FALLBACK</title>
481
If no plugins succeed, this program will, as a fallback, ask for
482
a password on the console using <citerefentry><refentrytitle
483
>getpass</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
484
and output it. This is not meant to be the normal mode of
485
operation, as there is a separate plugin for getting a password
490
263
<refsect1 id="exit_status">
491
264
<title>EXIT STATUS</title>
493
Exit status of this program is zero if no errors were
494
encountered, and otherwise not. The fallback (see <xref
495
linkend="fallback"/>) may or may not have succeeded in either
500
<refsect1 id="environment">
501
<title>ENVIRONMENT</title>
503
This program does not use any environment variables itself, it
504
only passes on its environment to all the plugins. The
505
environment passed to plugins can be modified using the
506
<option>--global-env</option> and <option>--env-for</option>
507
options. Also, the <option>--plugin-helper-dir</option> option
508
will affect the environment variable
509
<envar>MANDOSPLUGINHELPERDIR</envar> for the plugins.
513
<refsect1 id="files">
514
270
<title>FILES</title>
519
>/conf/conf.d/mandos/plugin-runner.conf</filename></term>
522
Since this program will be run as a keyscript, there is
523
little to no opportunity to pass command line arguments
524
to it. Therefore, it will <emphasis>also</emphasis>
525
read this file and use its contents as
526
whitespace-separated command line options. Also,
527
everything from a <quote>#</quote> character to the end
528
of a line is ignored.
531
This program is meant to run in the initial RAM disk
532
environment, so that is where this file is assumed to
533
exist. The file does not need to exist in the normal
537
This file will be processed <emphasis>before</emphasis>
538
the normal command line options, so the latter can
539
override the former, if need be.
542
This file name is the default; the file to read for
543
arguments can be changed using the
544
<option>--config-file</option> option.
549
<term><filename class="directory"
550
>/lib/mandos/plugins.d</filename></term>
553
The default plugin directory; can be changed by the
554
<option>--plugin-dir</option> option.
559
<term><filename class="directory"
560
>/lib/mandos/plugin-helpers</filename></term>
563
The default plugin helper directory; can be changed by
564
the <option>--plugin-helper-dir</option> option.
275
<refsect1 id="notes">
572
281
<refsect1 id="bugs">
573
282
<title>BUGS</title>
575
The <option>--config-file</option> option is ignored when
576
specified from within a configuration file.
578
<xi:include href="bugs.xml"/>
581
287
<refsect1 id="examples">
582
288
<title>EXAMPLE</title>
585
Normal invocation needs no options:
588
<userinput>&COMMANDNAME;</userinput>
593
Run the program, but not the plugins, in debug mode:
597
<!-- do not wrap this line -->
598
<userinput>&COMMANDNAME; --debug</userinput>
604
Run all plugins, but run the <quote>foo</quote> plugin in
609
<!-- do not wrap this line -->
610
<userinput>&COMMANDNAME; --options-for=foo:--debug</userinput>
616
Run all plugins, but not the program, in debug mode:
620
<!-- do not wrap this line -->
621
<userinput>&COMMANDNAME; --global-options=--debug</userinput>
627
Read a different configuration file, run plugins from a
628
different directory, specify an alternate plugin helper
629
directory and add two options to the
630
<citerefentry><refentrytitle >mandos-client</refentrytitle>
631
<manvolnum>8mandos</manvolnum></citerefentry> plugin:
635
<!-- do not wrap this line -->
636
<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</userinput>
641
293
<refsect1 id="security">
642
294
<title>SECURITY</title>
644
This program will, when starting, try to switch to another user.
645
If it is started as root, it will succeed, and will by default
646
switch to user and group 65534, which are assumed to be
647
non-privileged. This user and group is then what all plugins
648
will be started as. Therefore, the only way to run a plugin as
649
a privileged user is to have the set-user-ID or set-group-ID bit
650
set on the plugin executable file (see <citerefentry>
651
<refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum>
655
If this program is used as a keyscript in <citerefentry
656
><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum>
657
</citerefentry>, there is a slight risk that if this program
658
fails to work, there might be no way to boot the system except
659
for booting from another media and editing the initial RAM disk
660
image to not run this program. This is, however, unlikely,
661
since the <citerefentry><refentrytitle
662
>password-prompt</refentrytitle><manvolnum>8mandos</manvolnum>
663
</citerefentry> plugin will read a password from the console in
664
case of failure of the other plugins, and this plugin runner
665
will also, in case of catastrophic failure, itself fall back to
666
asking and outputting a password on the console (see <xref
667
linkend="fallback"/>).
671
299
<refsect1 id="see_also">
672
300
<title>SEE ALSO</title>
674
<citerefentry><refentrytitle>intro</refentrytitle>
675
<manvolnum>8mandos</manvolnum></citerefentry>,
676
302
<citerefentry><refentrytitle>cryptsetup</refentrytitle>
677
303
<manvolnum>8</manvolnum></citerefentry>,
678
<citerefentry><refentrytitle>crypttab</refentrytitle>
679
<manvolnum>5</manvolnum></citerefentry>,
680
<citerefentry><refentrytitle>execve</refentrytitle>
681
<manvolnum>2</manvolnum></citerefentry>,
682
304
<citerefentry><refentrytitle>mandos</refentrytitle>
683
305
<manvolnum>8</manvolnum></citerefentry>,
684
306
<citerefentry><refentrytitle>password-prompt</refentrytitle>
685
307
<manvolnum>8mandos</manvolnum></citerefentry>,
686
<citerefentry><refentrytitle>mandos-client</refentrytitle>
308
<citerefentry><refentrytitle>password-request</refentrytitle>
687
309
<manvolnum>8mandos</manvolnum></citerefentry>
692
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