127
143
</refsynopsisdiv>
129
145
<refsect1 id="description">
130
146
<title>DESCRIPTION</title>
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
148
<command>&COMMANDNAME;</command> is a program which is meant to
149
be specified as a <quote>keyscript</quote> for the root disk in
138
150
<citerefentry><refentrytitle>crypttab</refentrytitle>
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.
151
<manvolnum>5</manvolnum></citerefentry>. The aim of this
152
program is therefore to output a password, which then
153
<citerefentry><refentrytitle>cryptsetup</refentrytitle>
154
<manvolnum>8</manvolnum></citerefentry> will use to unlock the
158
This program is not meant to be invoked directly, but can be in
159
order to test it. Note that any password obtained will simply
160
be output on standard output.
164
<refsect1 id="purpose">
165
<title>PURPOSE</title>
167
The purpose of this is to enable <emphasis>remote and unattended
168
rebooting</emphasis> of client host computer with an
169
<emphasis>encrypted root file system</emphasis>. See <xref
170
linkend="overview"/> for details.
149
175
<title>OPTIONS</title>
178
<term><option>--global-env
179
<replaceable>ENV</replaceable><literal>=</literal><replaceable
180
>value</replaceable></option></term>
182
<replaceable>ENV</replaceable><literal>=</literal><replaceable
183
>value</replaceable></option></term>
186
This option will add an environment variable setting to
187
all plugins. This will override any inherited environment
194
<term><option>--env-for
195
<replaceable>PLUGIN</replaceable><literal>:</literal
196
><replaceable>ENV</replaceable><literal>=</literal
197
><replaceable>value</replaceable></option></term>
199
<replaceable>PLUGIN</replaceable><literal>:</literal
200
><replaceable>ENV</replaceable><literal>=</literal
201
><replaceable>value</replaceable></option></term>
204
This option will add an environment variable setting to
205
the <replaceable>PLUGIN</replaceable> plugin. This will
206
override any inherited environment variables or
207
environment variables specified using
208
<option>--global-env</option>.
152
214
<term><option>--global-options
153
215
<replaceable>OPTIONS</replaceable></option></term>
155
217
<replaceable>OPTIONS</replaceable></option></term>
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.
220
Pass some options to <emphasis>all</emphasis> plugins.
221
<replaceable>OPTIONS</replaceable> is a comma separated
222
list of options. This is not a very useful option, except
223
for specifying the <quote><option>--debug</option></quote>
224
option to all plugins.
166
230
<term><option>--options-for
167
231
<replaceable>PLUGIN</replaceable><literal>:</literal
171
235
><replaceable>OPTION</replaceable></option></term>
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.
238
Pass some options to a specific plugin. <replaceable
239
>PLUGIN</replaceable> is the name (file basename) of a
240
plugin, and <replaceable>OPTIONS</replaceable> is a comma
241
separated list of options.
244
Note that since options are not split on whitespace, the
245
way to pass, to the plugin
246
<quote><filename>foo</filename></quote>, the option
247
<option>--bar</option> with the option argument
248
<quote>baz</quote> is either
249
<userinput>--options-for=foo:--bar=baz</userinput> or
250
<userinput>--options-for=foo:--bar,baz</userinput>. Using
251
<userinput>--options-for="foo:--bar baz"</userinput>. will
252
<emphasis>not</emphasis> work.
182
<term><option> --disable
258
<term><option>--disable
183
259
<replaceable>PLUGIN</replaceable></option></term>
185
261
<replaceable>PLUGIN</replaceable></option></term>
188
Disable a specific plugin
264
Disable the plugin named
265
<replaceable>PLUGIN</replaceable>. The plugin will not be
272
<term><option>--enable
273
<replaceable>PLUGIN</replaceable></option></term>
275
<replaceable>PLUGIN</replaceable></option></term>
278
Re-enable the plugin named
279
<replaceable>PLUGIN</replaceable>. This is only useful to
280
undo a previous <option>--disable</option> option, maybe
281
from the configuration file.
194
287
<term><option>--groupid
195
288
<replaceable>ID</replaceable></option></term>
198
Group ID the plugins will run as
291
Change to group ID <replaceable>ID</replaceable> on
292
startup. The default is 65534. All plugins will be
293
started using this group ID. <emphasis>Note:</emphasis>
294
This must be a number, not a name.
204
300
<term><option>--userid
205
301
<replaceable>ID</replaceable></option></term>
208
User ID the plugins will run as
304
Change to user ID <replaceable>ID</replaceable> on
305
startup. The default is 65534. All plugins will be
306
started using this user ID. <emphasis>Note:</emphasis>
307
This must be a number, not a name.
214
313
<term><option>--plugin-dir
215
314
<replaceable>DIRECTORY</replaceable></option></term>
218
Specify a different plugin directory
317
Specify a different plugin directory. The default is
318
<filename>/lib/mandos/plugins.d</filename>, which will
319
exist in the initial <acronym>RAM</acronym> disk
326
<term><option>--plugin-helper-dir
327
<replaceable>DIRECTORY</replaceable></option></term>
330
Specify a different plugin helper directory. The default
331
is <filename>/lib/mandos/plugin-helpers</filename>, which
332
will exist in the initial <acronym>RAM</acronym> disk
333
environment. (This will simply be passed to all plugins
334
via the <envar>MANDOSPLUGINHELPERDIR</envar> environment
335
variable. See <xref linkend="writing_plugins"/>)
341
<term><option>--config-file
342
<replaceable>FILE</replaceable></option></term>
345
Specify a different file to read additional options from.
346
See <xref linkend="files"/>. Other command line options
347
will override options specified in the file.
243
382
<term><option>--usage</option></term>
246
Gives a short usage message
385
Gives a short usage message.
252
391
<term><option>--version</option></term>
253
392
<term><option>-V</option></term>
256
Prints the program version
395
Prints the program version.
402
<refsect1 id="overview">
403
<title>OVERVIEW</title>
404
<xi:include href="overview.xml"/>
406
This program will run on the client side in the initial
407
<acronym>RAM</acronym> disk environment, and is responsible for
408
getting a password. It does this by running plugins, one of
409
which will normally be the actual client program communicating
413
<refsect1 id="plugins">
414
<title>PLUGINS</title>
416
This program will get a password by running a number of
417
<firstterm>plugins</firstterm>, which are simply executable
418
programs in a directory in the initial <acronym>RAM</acronym>
419
disk environment. The default directory is
420
<filename>/lib/mandos/plugins.d</filename>, but this can be
421
changed with the <option>--plugin-dir</option> option. The
422
plugins are started in parallel, and the first plugin to output
423
a password <emphasis>and</emphasis> exit with a successful exit
424
code will make this plugin-runner output the password from that
425
plugin, stop any other plugins, and exit.
428
<refsect2 id="writing_plugins">
429
<title>WRITING PLUGINS</title>
431
A plugin is simply a program which prints a password to its
432
standard output and then exits with a successful (zero) exit
433
status. If the exit status is not zero, any output on
434
standard output will be ignored by the plugin runner. Any
435
output on its standard error channel will simply be passed to
436
the standard error of the plugin runner, usually the system
440
If the password is a single-line, manually entered passprase,
441
a final trailing newline character should
442
<emphasis>not</emphasis> be printed.
445
The plugin will run in the initial RAM disk environment, so
446
care must be taken not to depend on any files or running
447
services not available there. Any helper executables required
448
by the plugin (which are not in the <envar>PATH</envar>) can
449
be placed in the plugin helper directory, the name of which
450
will be made available to the plugin via the
451
<envar>MANDOSPLUGINHELPERDIR</envar> environment variable.
454
The plugin must exit cleanly and free all allocated resources
455
upon getting the TERM signal, since this is what the plugin
456
runner uses to stop all other plugins when one plugin has
457
output a password and exited cleanly.
460
The plugin must not use resources, like for instance reading
461
from the standard input, without knowing that no other plugin
465
It is useful, but not required, for the plugin to take the
466
<option>--debug</option> option.
471
<refsect1 id="fallback">
472
<title>FALLBACK</title>
474
If no plugins succeed, this program will, as a fallback, ask for
475
a password on the console using <citerefentry><refentrytitle
476
>getpass</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
477
and output it. This is not meant to be the normal mode of
478
operation, as there is a separate plugin for getting a password
263
483
<refsect1 id="exit_status">
264
484
<title>EXIT STATUS</title>
486
Exit status of this program is zero if no errors were
487
encountered, and otherwise not. The fallback (see <xref
488
linkend="fallback"/>) may or may not have succeeded in either
493
<refsect1 id="environment">
494
<title>ENVIRONMENT</title>
496
This program does not use any environment variables itself, it
497
only passes on its environment to all the plugins. The
498
environment passed to plugins can be modified using the
499
<option>--global-env</option> and <option>--env-for</option>
500
options. Also, the <option>--plugin-helper-dir</option> option
501
will affect the environment variable
502
<envar>MANDOSPLUGINHELPERDIR</envar> for the plugins.
506
<refsect1 id="files">
270
507
<title>FILES</title>
275
<refsect1 id="notes">
512
>/conf/conf.d/mandos/plugin-runner.conf</filename></term>
515
Since this program will be run as a keyscript, there is
516
little to no opportunity to pass command line arguments
517
to it. Therefore, it will <emphasis>also</emphasis>
518
read this file and use its contents as
519
whitespace-separated command line options. Also,
520
everything from a <quote>#</quote> character to the end
521
of a line is ignored.
524
This program is meant to run in the initial RAM disk
525
environment, so that is where this file is assumed to
526
exist. The file does not need to exist in the normal
530
This file will be processed <emphasis>before</emphasis>
531
the normal command line options, so the latter can
532
override the former, if need be.
535
This file name is the default; the file to read for
536
arguments can be changed using the
537
<option>--config-file</option> option.
281
545
<refsect1 id="bugs">
282
546
<title>BUGS</title>
548
The <option>--config-file</option> option is ignored when
549
specified from within a configuration file.
287
553
<refsect1 id="examples">
288
554
<title>EXAMPLE</title>
557
Normal invocation needs no options:
560
<userinput>&COMMANDNAME;</userinput>
565
Run the program, but not the plugins, in debug mode:
569
<!-- do not wrap this line -->
570
<userinput>&COMMANDNAME; --debug</userinput>
576
Run all plugins, but run the <quote>foo</quote> plugin in
581
<!-- do not wrap this line -->
582
<userinput>&COMMANDNAME; --options-for=foo:--debug</userinput>
588
Run all plugins, but not the program, in debug mode:
592
<!-- do not wrap this line -->
593
<userinput>&COMMANDNAME; --global-options=--debug</userinput>
599
Read a different configuration file, run plugins from a
600
different directory, specify an alternate plugin helper
601
directory and add two options to the
602
<citerefentry><refentrytitle >mandos-client</refentrytitle>
603
<manvolnum>8mandos</manvolnum></citerefentry> plugin:
607
<!-- do not wrap this line -->
608
<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>
293
613
<refsect1 id="security">
294
614
<title>SECURITY</title>
616
This program will, when starting, try to switch to another user.
617
If it is started as root, it will succeed, and will by default
618
switch to user and group 65534, which are assumed to be
619
non-privileged. This user and group is then what all plugins
620
will be started as. Therefore, the only way to run a plugin as
621
a privileged user is to have the set-user-ID or set-group-ID bit
622
set on the plugin executable file (see <citerefentry>
623
<refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum>
627
If this program is used as a keyscript in <citerefentry
628
><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum>
629
</citerefentry>, there is a slight risk that if this program
630
fails to work, there might be no way to boot the system except
631
for booting from another media and editing the initial RAM disk
632
image to not run this program. This is, however, unlikely,
633
since the <citerefentry><refentrytitle
634
>password-prompt</refentrytitle><manvolnum>8mandos</manvolnum>
635
</citerefentry> plugin will read a password from the console in
636
case of failure of the other plugins, and this plugin runner
637
will also, in case of catastrophic failure, itself fall back to
638
asking and outputting a password on the console (see <xref
639
linkend="fallback"/>).
299
643
<refsect1 id="see_also">
300
644
<title>SEE ALSO</title>
646
<citerefentry><refentrytitle>intro</refentrytitle>
647
<manvolnum>8mandos</manvolnum></citerefentry>,
302
648
<citerefentry><refentrytitle>cryptsetup</refentrytitle>
303
649
<manvolnum>8</manvolnum></citerefentry>,
650
<citerefentry><refentrytitle>crypttab</refentrytitle>
651
<manvolnum>5</manvolnum></citerefentry>,
652
<citerefentry><refentrytitle>execve</refentrytitle>
653
<manvolnum>2</manvolnum></citerefentry>,
304
654
<citerefentry><refentrytitle>mandos</refentrytitle>
305
655
<manvolnum>8</manvolnum></citerefentry>,
306
656
<citerefentry><refentrytitle>password-prompt</refentrytitle>
307
657
<manvolnum>8mandos</manvolnum></citerefentry>,
308
<citerefentry><refentrytitle>password-request</refentrytitle>
658
<citerefentry><refentrytitle>mandos-client</refentrytitle>
309
659
<manvolnum>8mandos</manvolnum></citerefentry>
314
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