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<arg choice="plain"><option>--global-env=<replaceable
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>VAR</replaceable><literal>=</literal><replaceable
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>value</replaceable></option></arg>
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<arg choice="plain"><option>-G
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<arg choice="plain"><option>-e
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<replaceable>VAR</replaceable><literal>=</literal><replaceable
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>value</replaceable> </option></arg>
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>PLUGIN</replaceable><literal>:</literal><replaceable
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>ENV</replaceable><literal>=</literal><replaceable
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>value</replaceable></option></arg>
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<arg choice="plain"><option>-E<replaceable>
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<arg choice="plain"><option>-f<replaceable>
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PLUGIN</replaceable><literal>:</literal><replaceable
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>ENV</replaceable><literal>=</literal><replaceable
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>value</replaceable> </option></arg>
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<arg choice="plain"><option>--options-for=<replaceable
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>PLUGIN</replaceable><literal>:</literal><replaceable
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>OPTIONS</replaceable></option></arg>
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<arg choice="plain"><option>-o<replaceable>
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<arg choice="plain"><option>-f<replaceable>
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PLUGIN</replaceable><literal>:</literal><replaceable
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>OPTIONS</replaceable> </option></arg>
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<replaceable>PLUGIN</replaceable> </option></arg>
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<arg choice="plain"><option>--enable=<replaceable
100
>PLUGIN</replaceable></option></arg>
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<arg choice="plain"><option>-e
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<replaceable>PLUGIN</replaceable> </option></arg>
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<arg><option>--groupid=<replaceable
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99
>ID</replaceable></option></arg>
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<title>DESCRIPTION</title>
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<command>&COMMANDNAME;</command> is a program which is meant to
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be specified as a <quote>keyscript</quote> for the root disk in
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<citerefentry><refentrytitle>crypttab</refentrytitle>
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<manvolnum>5</manvolnum></citerefentry>. The aim of this
146
program is therefore to output a password, which then
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<citerefentry><refentrytitle>cryptsetup</refentrytitle>
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<manvolnum>8</manvolnum></citerefentry> will use to unlock the
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be specified as <quote>keyscript</quote> in <citerefentry>
134
<refentrytitle>crypttab</refentrytitle>
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<manvolnum>5</manvolnum></citerefentry> for the root disk. The
136
aim of this program is therefore to output a password, which
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then <citerefentry><refentrytitle>cryptsetup</refentrytitle>
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<manvolnum>8</manvolnum></citerefentry> will use to try and
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unlock the root disk.
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142
This program is not meant to be invoked directly, but can be in
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<option>--bar</option> with the option argument
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<quote>baz</quote> is either
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<userinput>--options-for=foo:--bar=baz</userinput> or
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<userinput>--options-for=foo:--bar,baz</userinput>. Using
245
<userinput>--options-for="foo:--bar baz"</userinput>. will
246
<emphasis>not</emphasis> work.
234
<userinput>--options-for=foo:--bar,baz</userinput>, but
235
<emphasis>not</emphasis>
236
<userinput>--options-for="foo:--bar baz"</userinput>.
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<term><option>--disable
242
<term><option> --disable
253
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<replaceable>PLUGIN</replaceable></option></term>
255
245
<replaceable>PLUGIN</replaceable></option></term>
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<term><option>--enable
267
<replaceable>PLUGIN</replaceable></option></term>
269
<replaceable>PLUGIN</replaceable></option></term>
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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.
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<term><option>--groupid
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257
<replaceable>ID</replaceable></option></term>
403
366
code will make this plugin-runner output the password from that
404
367
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
The plugin will run in the initial RAM disk environment, so
420
care must be taken not to depend on any files or running
421
services not available there.
424
The plugin must exit cleanly and free all allocated resources
425
upon getting the TERM signal, since this is what the plugin
426
runner uses to stop all other plugins when one plugin has
427
output a password and exited cleanly.
430
The plugin must not use resources, like for instance reading
431
from the standard input, without knowing that no other plugin
435
It is useful, but not required, for the plugin to take the
436
<option>--debug</option> option.
441
371
<refsect1 id="fallback">
489
415
of a line is ignored.
492
This program is meant to run in the initial RAM disk
493
environment, so that is where this file is assumed to
494
exist. The file does not need to exist in the normal
498
418
This file will be processed <emphasis>before</emphasis>
499
419
the normal command line options, so the latter can
500
420
override the former, if need be.
503
This file name is the default; the file to read for
504
arguments can be changed using the
505
<option>--config-file</option> option.
513
428
<refsect1 id="bugs">
514
429
<title>BUGS</title>
516
The <option>--config-file</option> option is ignored when
517
specified from within a configuration file.
431
There is no <option>--enable</option> option to enable disabled
521
436
<refsect1 id="examples">
522
437
<title>EXAMPLE</title>
525
Normal invocation needs no options:
528
<userinput>&COMMANDNAME;</userinput>
533
Run the program, but not the plugins, in debug mode:
537
<!-- do not wrap this line -->
538
<userinput>&COMMANDNAME; --debug</userinput>
544
Run all plugins, but run the <quote>foo</quote> plugin in
549
<!-- do not wrap this line -->
550
<userinput>&COMMANDNAME; --options-for=foo:--debug</userinput>
556
Run all plugins, but not the program, in debug mode:
560
<!-- do not wrap this line -->
561
<userinput>&COMMANDNAME; --global-options=--debug</userinput>
567
Run plugins from a different directory and add two
568
options to the <citerefentry><refentrytitle
569
>password-request</refentrytitle>
570
<manvolnum>8mandos</manvolnum></citerefentry> plugin:
574
<!-- do not wrap this line -->
575
<userinput>&COMMANDNAME; --plugin-dir=plugins.d --options-for=password-request:--pubkey=keydir/pubkey.txt,--seckey=keydir/seckey.txt</userinput>
580
442
<refsect1 id="security">
581
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<title>SECURITY</title>
583
This program will, when starting, try to switch to another user.
584
If it is started as root, it will succeed, and will by default
585
switch to user and group 65534, which are assumed to be
586
non-privileged. This user and group is then what all plugins
587
will be started as. Therefore, the only way to run a plugin as
588
a privileged user is to have the set-user-ID or set-group-ID bit
589
set on the plugin executable files (see <citerefentry>
590
<refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum>
594
If this program is used as a keyscript in <citerefentry
595
><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum>
596
</citerefentry>, there is a slight risk that if this program
597
fails to work, there might be no way to boot the system except
598
for booting from another media and editing the initial RAM disk
599
image to not run this program. This is, however, unlikely,
600
since the <citerefentry><refentrytitle
601
>password-prompt</refentrytitle><manvolnum>8mandos</manvolnum>
602
</citerefentry> plugin will read a password from the console in
603
case of failure of the other plugins, and this plugin runner
604
will also, in case of catastrophic failure, itself fall back to
605
asking and outputting a password on the console (see <xref
606
linkend="fallback"/>).
613
451
<citerefentry><refentrytitle>cryptsetup</refentrytitle>
614
452
<manvolnum>8</manvolnum></citerefentry>,
615
<citerefentry><refentrytitle>crypttab</refentrytitle>
616
<manvolnum>5</manvolnum></citerefentry>,
617
<citerefentry><refentrytitle>execve</refentrytitle>
618
<manvolnum>2</manvolnum></citerefentry>,
619
453
<citerefentry><refentrytitle>mandos</refentrytitle>
620
454
<manvolnum>8</manvolnum></citerefentry>,
621
455
<citerefentry><refentrytitle>password-prompt</refentrytitle>