1
1
<?xml version="1.0" encoding="UTF-8"?>
2
2
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3
3
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4
<!ENTITY VERSION "1.0">
5
4
<!ENTITY COMMANDNAME "plugin-runner">
6
<!ENTITY TIMESTAMP "2008-09-02">
5
<!ENTITY TIMESTAMP "2008-09-30">
6
<!ENTITY % common SYSTEM "common.ent">
9
10
<refentry xmlns:xi="http://www.w3.org/2001/XInclude">
46
47
<refname><command>&COMMANDNAME;</command></refname>
48
Run Mandos plugins. Pass data from first succesful one.
49
Run Mandos plugins, pass data from first to succeed.
54
55
<command>&COMMANDNAME;</command>
55
56
<group rep="repeat">
56
57
<arg choice="plain"><option>--global-env=<replaceable
57
>VAR</replaceable><literal>=</literal><replaceable
58
>ENV</replaceable><literal>=</literal><replaceable
58
59
>value</replaceable></option></arg>
59
60
<arg choice="plain"><option>-G
60
<replaceable>VAR</replaceable><literal>=</literal><replaceable
61
<replaceable>ENV</replaceable><literal>=</literal><replaceable
61
62
>value</replaceable> </option></arg>
140
141
<title>DESCRIPTION</title>
142
143
<command>&COMMANDNAME;</command> is a program which is meant to
143
be specified as <quote>keyscript</quote> in <citerefentry>
144
<refentrytitle>crypttab</refentrytitle>
145
<manvolnum>5</manvolnum></citerefentry> for the root disk. The
146
aim of this program is therefore to output a password, which
147
then <citerefentry><refentrytitle>cryptsetup</refentrytitle>
148
<manvolnum>8</manvolnum></citerefentry> will use to try and
149
unlock the root disk.
144
be specified as a <quote>keyscript</quote> for the root disk in
145
<citerefentry><refentrytitle>crypttab</refentrytitle>
146
<manvolnum>5</manvolnum></citerefentry>. The aim of this
147
program is therefore to output a password, which then
148
<citerefentry><refentrytitle>cryptsetup</refentrytitle>
149
<manvolnum>8</manvolnum></citerefentry> will use to unlock the
152
153
This program is not meant to be invoked directly, but can be in
172
173
<term><option>--global-env
173
<replaceable>VAR</replaceable><literal>=</literal><replaceable
174
<replaceable>ENV</replaceable><literal>=</literal><replaceable
174
175
>value</replaceable></option></term>
176
<replaceable>VAR</replaceable><literal>=</literal><replaceable
177
<replaceable>ENV</replaceable><literal>=</literal><replaceable
177
178
>value</replaceable></option></term>
241
242
<option>--bar</option> with the option argument
242
243
<quote>baz</quote> is either
243
244
<userinput>--options-for=foo:--bar=baz</userinput> or
244
<userinput>--options-for=foo:--bar,baz</userinput>, but
245
<emphasis>not</emphasis>
246
<userinput>--options-for="foo:--bar baz"</userinput>.
245
<userinput>--options-for=foo:--bar,baz</userinput>. Using
246
<userinput>--options-for="foo:--bar baz"</userinput>. will
247
<emphasis>not</emphasis> work.
252
253
<term><option>--disable
253
254
<replaceable>PLUGIN</replaceable></option></term>
403
404
code will make this plugin-runner output the password from that
404
405
plugin, stop any other plugins, and exit.
408
<refsect2 id="writing_plugins">
409
<title>WRITING PLUGINS</title>
411
A plugin is simply a program which prints a password to its
412
standard output and then exits with a successful (zero) exit
413
status. If the exit status is not zero, any output on
414
standard output will be ignored by the plugin runner. Any
415
output on its standard error channel will simply be passed to
416
the standard error of the plugin runner, usually the system
420
If the password is a single-line, manually entered passprase,
421
a final trailing newline character should
422
<emphasis>not</emphasis> be printed.
425
The plugin will run in the initial RAM disk environment, so
426
care must be taken not to depend on any files or running
427
services not available there.
430
The plugin must exit cleanly and free all allocated resources
431
upon getting the TERM signal, since this is what the plugin
432
runner uses to stop all other plugins when one plugin has
433
output a password and exited cleanly.
436
The plugin must not use resources, like for instance reading
437
from the standard input, without knowing that no other plugin
441
It is useful, but not required, for the plugin to take the
442
<option>--debug</option> option.
408
447
<refsect1 id="fallback">
480
519
<refsect1 id="bugs">
481
520
<title>BUGS</title>
522
The <option>--config-file</option> option is ignored when
523
specified from within a configuration file.
486
527
<refsect1 id="examples">
487
528
<title>EXAMPLE</title>
531
Normal invocation needs no options:
534
<userinput>&COMMANDNAME;</userinput>
539
Run the program, but not the plugins, in debug mode:
543
<!-- do not wrap this line -->
544
<userinput>&COMMANDNAME; --debug</userinput>
550
Run all plugins, but run the <quote>foo</quote> plugin in
555
<!-- do not wrap this line -->
556
<userinput>&COMMANDNAME; --options-for=foo:--debug</userinput>
562
Run all plugins, but not the program, in debug mode:
566
<!-- do not wrap this line -->
567
<userinput>&COMMANDNAME; --global-options=--debug</userinput>
573
Run plugins from a different directory, read a different
574
configuration file, and add two options to the
575
<citerefentry><refentrytitle >mandos-client</refentrytitle>
576
<manvolnum>8mandos</manvolnum></citerefentry> plugin:
580
<!-- do not wrap this line -->
581
<userinput>&COMMANDNAME; --config-file=/etc/mandos/plugin-runner.conf --plugin-dir /usr/lib/mandos/plugins.d --options-for=mandos-client:--pubkey=/etc/keys/mandos/pubkey.txt,--seckey=/etc/keys/mandos/seckey.txt</userinput>
492
586
<refsect1 id="security">
493
587
<title>SECURITY</title>
589
This program will, when starting, try to switch to another user.
590
If it is started as root, it will succeed, and will by default
591
switch to user and group 65534, which are assumed to be
592
non-privileged. This user and group is then what all plugins
593
will be started as. Therefore, the only way to run a plugin as
594
a privileged user is to have the set-user-ID or set-group-ID bit
595
set on the plugin executable file (see <citerefentry>
596
<refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum>
600
If this program is used as a keyscript in <citerefentry
601
><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum>
602
</citerefentry>, there is a slight risk that if this program
603
fails to work, there might be no way to boot the system except
604
for booting from another media and editing the initial RAM disk
605
image to not run this program. This is, however, unlikely,
606
since the <citerefentry><refentrytitle
607
>password-prompt</refentrytitle><manvolnum>8mandos</manvolnum>
608
</citerefentry> plugin will read a password from the console in
609
case of failure of the other plugins, and this plugin runner
610
will also, in case of catastrophic failure, itself fall back to
611
asking and outputting a password on the console (see <xref
612
linkend="fallback"/>).
501
619
<citerefentry><refentrytitle>cryptsetup</refentrytitle>
502
620
<manvolnum>8</manvolnum></citerefentry>,
621
<citerefentry><refentrytitle>crypttab</refentrytitle>
622
<manvolnum>5</manvolnum></citerefentry>,
623
<citerefentry><refentrytitle>execve</refentrytitle>
624
<manvolnum>2</manvolnum></citerefentry>,
503
625
<citerefentry><refentrytitle>mandos</refentrytitle>
504
626
<manvolnum>8</manvolnum></citerefentry>,
505
627
<citerefentry><refentrytitle>password-prompt</refentrytitle>
506
628
<manvolnum>8mandos</manvolnum></citerefentry>,
507
<citerefentry><refentrytitle>password-request</refentrytitle>
629
<citerefentry><refentrytitle>mandos-client</refentrytitle>
508
630
<manvolnum>8mandos</manvolnum></citerefentry>