128
111
<arg><option>--plugin-dir=<replaceable
129
112
>DIRECTORY</replaceable></option></arg>
114
<arg><option>--config-file=<replaceable
115
>FILE</replaceable></option></arg>
131
117
<arg><option>--debug</option></arg>
134
120
<command>&COMMANDNAME;</command>
135
121
<group choice="req">
136
<arg choice='plain'><option>--help</option></arg>
137
<arg choice='plain'><option>-?</option></arg>
122
<arg choice="plain"><option>--help</option></arg>
123
<arg choice="plain"><option>-?</option></arg>
141
127
<command>&COMMANDNAME;</command>
142
<arg choice='plain'><option>--usage</option></arg>
128
<arg choice="plain"><option>--usage</option></arg>
145
131
<command>&COMMANDNAME;</command>
146
132
<group choice="req">
147
<arg choice='plain'><option>--version</option></arg>
148
<arg choice='plain'><option>-V</option></arg>
133
<arg choice="plain"><option>--version</option></arg>
134
<arg choice="plain"><option>-V</option></arg>
151
137
</refsynopsisdiv>
153
139
<refsect1 id="description">
154
140
<title>DESCRIPTION</title>
156
<command>&COMMANDNAME;</command> is a plugin runner that waits
157
for any of its plugins to return sucessfull with a password, and
158
passes it to cryptsetup as stdout message. This command is not
159
meant to be invoked directly, but is instead meant to be run by
160
cryptsetup by being specified in /etc/crypttab as a keyscript
161
and subsequlently started in the initrd environment. See
142
<command>&COMMANDNAME;</command> is a program which is meant to
143
be specified as a <quote>keyscript</quote> for the root disk in
162
144
<citerefentry><refentrytitle>crypttab</refentrytitle>
163
<manvolnum>5</manvolnum></citerefentry> for more information on
168
plugins is looked for in the plugins directory which by default will be
169
/conf/conf.d/mandos/plugins.d if not changed by option --plugin-dir.
145
<manvolnum>5</manvolnum></citerefentry>. The aim of this
146
program is therefore to output a password, which then
147
<citerefentry><refentrytitle>cryptsetup</refentrytitle>
148
<manvolnum>8</manvolnum></citerefentry> will use to unlock the
152
This program is not meant to be invoked directly, but can be in
153
order to test it. Note that any password obtained will simply
154
be output on standard output.
158
<refsect1 id="purpose">
159
<title>PURPOSE</title>
161
The purpose of this is to enable <emphasis>remote and unattended
162
rebooting</emphasis> of client host computer with an
163
<emphasis>encrypted root file system</emphasis>. See <xref
164
linkend="overview"/> for details.
173
169
<title>OPTIONS</title>
172
<term><option>--global-env
173
<replaceable>VAR</replaceable><literal>=</literal><replaceable
174
>value</replaceable></option></term>
176
<replaceable>VAR</replaceable><literal>=</literal><replaceable
177
>value</replaceable></option></term>
180
This option will add an environment variable setting to
181
all plugins. This will override any inherited environment
188
<term><option>--env-for
189
<replaceable>PLUGIN</replaceable><literal>:</literal
190
><replaceable>ENV</replaceable><literal>=</literal
191
><replaceable>value</replaceable></option></term>
193
<replaceable>PLUGIN</replaceable><literal>:</literal
194
><replaceable>ENV</replaceable><literal>=</literal
195
><replaceable>value</replaceable></option></term>
198
This option will add an environment variable setting to
199
the <replaceable>PLUGIN</replaceable> plugin. This will
200
override any inherited environment variables or
201
environment variables specified using
202
<option>--global-env</option>.
176
208
<term><option>--global-options
177
209
<replaceable>OPTIONS</replaceable></option></term>
179
211
<replaceable>OPTIONS</replaceable></option></term>
182
Global options given to all plugins as additional start
183
arguments. Options are specified with a -o flag followed
184
by a comma separated string of options.
214
Pass some options to <emphasis>all</emphasis> plugins.
215
<replaceable>OPTIONS</replaceable> is a comma separated
216
list of options. This is not a very useful option, except
217
for specifying the <quote><option>--debug</option></quote>
218
option to all plugins.
190
224
<term><option>--options-for
191
225
<replaceable>PLUGIN</replaceable><literal>:</literal
195
229
><replaceable>OPTION</replaceable></option></term>
198
Plugin specific options given to the plugin as additional
199
start arguments. Options are specified with a -o flag
200
followed by a comma separated string of options.
232
Pass some options to a specific plugin. <replaceable
233
>PLUGIN</replaceable> is the name (file basename) of a
234
plugin, and <replaceable>OPTIONS</replaceable> is a comma
235
separated list of options.
238
Note that since options are not split on whitespace, the
239
way to pass, to the plugin
240
<quote><filename>foo</filename></quote>, the option
241
<option>--bar</option> with the option argument
242
<quote>baz</quote> is either
243
<userinput>--options-for=foo:--bar=baz</userinput> or
244
<userinput>--options-for=foo:--bar,baz</userinput>. Using
245
<userinput>--options-for="foo:--bar baz"</userinput>. will
246
<emphasis>not</emphasis> work.
206
<term><option> --disable
252
<term><option>--disable
207
253
<replaceable>PLUGIN</replaceable></option></term>
209
255
<replaceable>PLUGIN</replaceable></option></term>
212
Disable a specific plugin
258
Disable the plugin named
259
<replaceable>PLUGIN</replaceable>. The plugin will not be
266
<term><option>--enable
267
<replaceable>PLUGIN</replaceable></option></term>
269
<replaceable>PLUGIN</replaceable></option></term>
272
Re-enable the plugin named
273
<replaceable>PLUGIN</replaceable>. This is only useful to
274
undo a previous <option>--disable</option> option, maybe
275
from the configuration file.
218
281
<term><option>--groupid
219
282
<replaceable>ID</replaceable></option></term>
222
Group ID the plugins will run as
285
Change to group ID <replaceable>ID</replaceable> on
286
startup. The default is 65534. All plugins will be
287
started using this group ID. <emphasis>Note:</emphasis>
288
This must be a number, not a name.
277
371
<term><option>-V</option></term>
280
Prints the program version
374
Prints the program version.
381
<refsect1 id="overview">
382
<title>OVERVIEW</title>
383
<xi:include href="overview.xml"/>
385
This program will run on the client side in the initial
386
<acronym>RAM</acronym> disk environment, and is responsible for
387
getting a password. It does this by running plugins, one of
388
which will normally be the actual client program communicating
392
<refsect1 id="plugins">
393
<title>PLUGINS</title>
395
This program will get a password by running a number of
396
<firstterm>plugins</firstterm>, which are simply executable
397
programs in a directory in the initial <acronym>RAM</acronym>
398
disk environment. The default directory is
399
<filename>/lib/mandos/plugins.d</filename>, but this can be
400
changed with the <option>--plugin-dir</option> option. The
401
plugins are started in parallel, and the first plugin to output
402
a password <emphasis>and</emphasis> exit with a successful exit
403
code will make this plugin-runner output the password from that
404
plugin, stop any other plugins, and exit.
407
<refsect2 id="writing_plugins">
408
<title>WRITING PLUGINS</title>
410
A plugin is simply a program which prints a password to its
411
standard output and then exits with a successful (zero) exit
412
status. If the exit status is not zero, any output on
413
standard output will be ignored by the plugin runner. Any
414
output on its standard error channel will simply be passed to
415
the standard error of the plugin runner, usually the system
419
If the password is a single-line, manually entered passprase,
420
a final trailing newline character should
421
<emphasis>not</emphasis> be printed.
424
The plugin will run in the initial RAM disk environment, so
425
care must be taken not to depend on any files or running
426
services not available there.
429
The plugin must exit cleanly and free all allocated resources
430
upon getting the TERM signal, since this is what the plugin
431
runner uses to stop all other plugins when one plugin has
432
output a password and exited cleanly.
435
The plugin must not use resources, like for instance reading
436
from the standard input, without knowing that no other plugin
440
It is useful, but not required, for the plugin to take the
441
<option>--debug</option> option.
446
<refsect1 id="fallback">
447
<title>FALLBACK</title>
449
If no plugins succeed, this program will, as a fallback, ask for
450
a password on the console using <citerefentry><refentrytitle
451
>getpass</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
452
and output it. This is not meant to be the normal mode of
453
operation, as there is a separate plugin for getting a password
287
458
<refsect1 id="exit_status">
288
459
<title>EXIT STATUS</title>
461
Exit status of this program is zero if no errors were
462
encountered, and otherwise not. The fallback (see <xref
463
linkend="fallback"/>) may or may not have succeeded in either
468
<refsect1 id="environment">
469
<title>ENVIRONMENT</title>
471
This program does not use any environment variables itself, it
472
only passes on its environment to all the plugins. The
473
environment passed to plugins can be modified using the
474
<option>--global-env</option> and <option>--env-for</option>
479
<refsect1 id="files">
294
480
<title>FILES</title>
299
<refsect1 id="notes">
485
>/conf/conf.d/mandos/plugin-runner.conf</filename></term>
488
Since this program will be run as a keyscript, there is
489
little to no opportunity to pass command line arguments
490
to it. Therefore, it will <emphasis>also</emphasis>
491
read this file and use its contents as
492
whitespace-separated command line options. Also,
493
everything from a <quote>#</quote> character to the end
494
of a line is ignored.
497
This program is meant to run in the initial RAM disk
498
environment, so that is where this file is assumed to
499
exist. The file does not need to exist in the normal
503
This file will be processed <emphasis>before</emphasis>
504
the normal command line options, so the latter can
505
override the former, if need be.
508
This file name is the default; the file to read for
509
arguments can be changed using the
510
<option>--config-file</option> option.
305
518
<refsect1 id="bugs">
306
519
<title>BUGS</title>
521
The <option>--config-file</option> option is ignored when
522
specified from within a configuration file.
311
526
<refsect1 id="examples">
312
527
<title>EXAMPLE</title>
530
Normal invocation needs no options:
533
<userinput>&COMMANDNAME;</userinput>
538
Run the program, but not the plugins, in debug mode:
542
<!-- do not wrap this line -->
543
<userinput>&COMMANDNAME; --debug</userinput>
549
Run all plugins, but run the <quote>foo</quote> plugin in
554
<!-- do not wrap this line -->
555
<userinput>&COMMANDNAME; --options-for=foo:--debug</userinput>
561
Run all plugins, but not the program, in debug mode:
565
<!-- do not wrap this line -->
566
<userinput>&COMMANDNAME; --global-options=--debug</userinput>
572
Run plugins from a different directory, read a different
573
configuration file, and add two options to the
574
<citerefentry><refentrytitle >password-request</refentrytitle>
575
<manvolnum>8mandos</manvolnum></citerefentry> plugin:
579
<!-- do not wrap this line -->
580
<userinput>&COMMANDNAME; --config-file=/etc/mandos/plugin-runner.conf --plugin-dir /usr/lib/mandos/plugins.d --options-for=password-request:--pubkey=/etc/keys/mandos/pubkey.txt,--seckey=/etc/keys/mandos/seckey.txt</userinput>
317
585
<refsect1 id="security">
318
586
<title>SECURITY</title>
588
This program will, when starting, try to switch to another user.
589
If it is started as root, it will succeed, and will by default
590
switch to user and group 65534, which are assumed to be
591
non-privileged. This user and group is then what all plugins
592
will be started as. Therefore, the only way to run a plugin as
593
a privileged user is to have the set-user-ID or set-group-ID bit
594
set on the plugin executable file (see <citerefentry>
595
<refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum>
599
If this program is used as a keyscript in <citerefentry
600
><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum>
601
</citerefentry>, there is a slight risk that if this program
602
fails to work, there might be no way to boot the system except
603
for booting from another media and editing the initial RAM disk
604
image to not run this program. This is, however, unlikely,
605
since the <citerefentry><refentrytitle
606
>password-prompt</refentrytitle><manvolnum>8mandos</manvolnum>
607
</citerefentry> plugin will read a password from the console in
608
case of failure of the other plugins, and this plugin runner
609
will also, in case of catastrophic failure, itself fall back to
610
asking and outputting a password on the console (see <xref
611
linkend="fallback"/>).
323
615
<refsect1 id="see_also">
324
616
<title>SEE ALSO</title>
326
618
<citerefentry><refentrytitle>cryptsetup</refentrytitle>
327
619
<manvolnum>8</manvolnum></citerefentry>,
620
<citerefentry><refentrytitle>crypttab</refentrytitle>
621
<manvolnum>5</manvolnum></citerefentry>,
622
<citerefentry><refentrytitle>execve</refentrytitle>
623
<manvolnum>2</manvolnum></citerefentry>,
328
624
<citerefentry><refentrytitle>mandos</refentrytitle>
329
625
<manvolnum>8</manvolnum></citerefentry>,
330
626
<citerefentry><refentrytitle>password-prompt</refentrytitle>