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Committer: Teddy Hogeborn
Date: 2008-09-02 17:42:53 UTC
Revision ID: teddy@fukt.bsnet.se-20080902174253-p3wxrq7z6ccnv7fs

* plugins.d/password-request.c (main): Change default GnuTLS priority
                                       string to
                             "SECURE256":!CTYPE-X.509:+CTYPE-OPENPGP".

* plugins.d/password-request.xml (DESCRIPTION): Improve wording.
  (PURPOSE, OVERVIEW): New sections.
  (OPTIONS): Improved wording.
  (EXIT STATUS): Add text.
  (ENVIRONMENT): Commented out.

files added:
.bzrignore

COPYING

initramfs-tools-hook

initramfs-tools-hook-conf

initramfs-tools-script

legalnotice.xml

mandos-clients.conf.xml

mandos-keygen

mandos-keygen.xml

mandos-options.xml

mandos.conf

mandos.conf.xml

mandos.xml

overview.xml

plugin-runner.xml

plugins.d/password-prompt.xml

plugins.d/password-request.xml

plugins.d/usplash

files removed:
ca.pem

cert.pem

client-cert.pem

client-key.pem

crl.pem

key.pem

files renamed:
mandos-clients.conf => clients.conf

server.py => mandos

plugbasedclient.c => plugin-runner.c

plugins.d/passprompt.c => plugins.d/password-prompt.c

plugins.d/mandosclient.c => plugins.d/password-request.c

files modified:
Makefile

TODO

Show diffs side-by-side

added added

removed removed

plugin-runner.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"

"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [

<!ENTITY VERSION "1.0">

<!ENTITY COMMANDNAME "plugin-runner">

<!ENTITY TIMESTAMP "2008-09-02">

<title>Mandos Manual</title>

<productname>Mandos</productname>

<productnumber>&VERSION;</productnumber>

<date>&TIMESTAMP;</date>

<firstname>Björn</firstname>

<surname>Påhlsson</surname>

<email>belorn@fukt.bsnet.se</email>

</address>

</author>

<firstname>Teddy</firstname>

<surname>Hogeborn</surname>

<email>teddy@fukt.bsnet.se</email>

</address>

</author>

</authorgroup>

<holder>Teddy Hogeborn</holder>

<holder>Björn Påhlsson</holder>

</copyright>

<xi:include href="legalnotice.xml"/>

</refentryinfo>

<refentrytitle>&COMMANDNAME;</refentrytitle>

<manvolnum>8mandos</manvolnum>

</refmeta>

<refname><command>&COMMANDNAME;</command></refname>

Run Mandos plugins. Pass data from first succesful one.

</refpurpose>

</refnamediv>

<command>&COMMANDNAME;</command>

<arg choice="plain"><option>--global-env=<replaceable

>VAR</replaceable><literal>=</literal><replaceable

>value</replaceable></option></arg>

<arg choice="plain"><option>-G

<replaceable>VAR</replaceable><literal>=</literal><replaceable

>value</replaceable> </option></arg>

</group>

<sbr/>

<arg choice="plain"><option>--env-for=<replaceable

>PLUGIN</replaceable><literal>:</literal><replaceable

>ENV</replaceable><literal>=</literal><replaceable

>value</replaceable></option></arg>

PLUGIN</replaceable><literal>:</literal><replaceable

>ENV</replaceable><literal>=</literal><replaceable

>value</replaceable> </option></arg>

</group>

<sbr/>

<arg choice="plain"><option>--global-options=<replaceable

>OPTIONS</replaceable></option></arg>

OPTIONS</replaceable> </option></arg>

</group>

<sbr/>

<arg choice="plain"><option>--options-for=<replaceable

>PLUGIN</replaceable><literal>:</literal><replaceable

>OPTIONS</replaceable></option></arg>

PLUGIN</replaceable><literal>:</literal><replaceable

>OPTIONS</replaceable> </option></arg>

</group>

<sbr/>

<arg choice="plain"><option>--disable=<replaceable

>PLUGIN</replaceable></option></arg>

<arg choice="plain"><option>-d

<replaceable>PLUGIN</replaceable> </option></arg>

</group>

<sbr/>

<arg choice="plain"><option>--enable=<replaceable

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>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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</group>

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<sbr/>

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<arg><option>--groupid=<replaceable

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>ID</replaceable></option></arg>

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<sbr/>

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<arg><option>--userid=<replaceable

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>ID</replaceable></option></arg>

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<sbr/>

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<arg><option>--plugin-dir=<replaceable

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>DIRECTORY</replaceable></option></arg>

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<sbr/>

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<arg><option>--config-file=<replaceable

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>FILE</replaceable></option></arg>

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<sbr/>

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<arg><option>--debug</option></arg>

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</cmdsynopsis>

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<command>&COMMANDNAME;</command>

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</group>

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</cmdsynopsis>

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<command>&COMMANDNAME;</command>

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<arg choice="plain"><option>--usage</option></arg>

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</cmdsynopsis>

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<command>&COMMANDNAME;</command>

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<arg choice="plain"><option>--version</option></arg>

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</group>

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</cmdsynopsis>

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</refsynopsisdiv>

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<title>DESCRIPTION</title>

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<para>

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<command>&COMMANDNAME;</command> is a program which is meant to

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be specified as <quote>keyscript</quote> in <citerefentry>

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<refentrytitle>crypttab</refentrytitle>

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<manvolnum>5</manvolnum></citerefentry> for the root disk. The

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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 unlock the

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root disk.

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</para>

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<para>

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This program is not meant to be invoked directly, but can be in

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order to test it. Note that any password obtained will simply

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be output on standard output.

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</para>

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</refsect1>

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<title>PURPOSE</title>

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<para>

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The purpose of this is to enable <emphasis>remote and unattended

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rebooting</emphasis> of client host computer with an

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<emphasis>encrypted root file system</emphasis>. See <xref

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linkend="overview"/> for details.

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</para>

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</refsect1>

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<title>OPTIONS</title>

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<term><option>--global-env

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<replaceable>VAR</replaceable><literal>=</literal><replaceable

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>value</replaceable></option></term>

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<term><option>-G

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<replaceable>VAR</replaceable><literal>=</literal><replaceable

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>value</replaceable></option></term>

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<para>

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This option will add an environment variable setting to

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all plugins. This will override any inherited environment

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variable.

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</para>

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</listitem>

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</varlistentry>

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<term><option>--env-for

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<replaceable>PLUGIN</replaceable><literal>:</literal

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><replaceable>ENV</replaceable><literal>=</literal

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><replaceable>value</replaceable></option></term>

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<term><option>-E

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<replaceable>PLUGIN</replaceable><literal>:</literal

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><replaceable>ENV</replaceable><literal>=</literal

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><replaceable>value</replaceable></option></term>

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<para>

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This option will add an environment variable setting to

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the <replaceable>PLUGIN</replaceable> plugin. This will

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override any inherited environment variables or

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environment variables specified using

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<option>--global-env</option>.

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</para>

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</listitem>

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</varlistentry>

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<term><option>--global-options

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<replaceable>OPTIONS</replaceable></option></term>

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<term><option>-g

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<replaceable>OPTIONS</replaceable></option></term>

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<para>

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Pass some options to <emphasis>all</emphasis> plugins.

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<replaceable>OPTIONS</replaceable> is a comma separated

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list of options. This is not a very useful option, except

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for specifying the <quote><option>--debug</option></quote>

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option to all plugins.

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</para>

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</listitem>

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</varlistentry>

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<term><option>--options-for

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<replaceable>PLUGIN</replaceable><literal>:</literal

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><replaceable>OPTION</replaceable></option></term>

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<term><option>-o

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<replaceable>PLUGIN</replaceable><literal>:</literal

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><replaceable>OPTION</replaceable></option></term>

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<para>

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Pass some options to a specific plugin. <replaceable

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>PLUGIN</replaceable> is the name (file basename) of a

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plugin, and <replaceable>OPTIONS</replaceable> is a comma

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separated list of options.

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</para>

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<para>

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Note that since options are not split on whitespace, the

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way to pass, to the plugin

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<quote><filename>foo</filename></quote>, the option

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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

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<userinput>--options-for="foo:--bar baz"</userinput>. will

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<emphasis>not</emphasis> work.

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</para>

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</listitem>

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</varlistentry>

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<term><option>--disable

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<replaceable>PLUGIN</replaceable></option></term>

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<term><option>-d

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<replaceable>PLUGIN</replaceable></option></term>

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<para>

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Disable the plugin named

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<replaceable>PLUGIN</replaceable>. The plugin will not be

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started.

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</para>

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</listitem>

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</varlistentry>

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<term><option>--enable

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<replaceable>PLUGIN</replaceable></option></term>

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<term><option>-e

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<replaceable>PLUGIN</replaceable></option></term>

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<para>

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Re-enable the plugin named

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<replaceable>PLUGIN</replaceable>. This is only useful to

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undo a previous <option>--disable</option> option, maybe

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from the config file.

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</para>

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</listitem>

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</varlistentry>

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<term><option>--groupid

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<para>

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Change to group ID <replaceable>ID</replaceable> on

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startup. The default is 65534. All plugins will be

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started using this group ID. <emphasis>Note:</emphasis>

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This must be a number, not a name.

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</para>

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</listitem>

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</varlistentry>

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<term><option>--userid

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<para>

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Change to user ID <replaceable>ID</replaceable> on

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startup. The default is 65534. All plugins will be

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started using this user ID. <emphasis>Note:</emphasis>

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This must be a number, not a name.

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</para>

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</listitem>

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</varlistentry>

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<term><option>--plugin-dir

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<replaceable>DIRECTORY</replaceable></option></term>

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<para>

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Specify a different plugin directory. The default is

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<filename>/lib/mandos/plugins.d</filename>, which will

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exist in the initial <acronym>RAM</acronym> disk

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environment.

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</para>

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</listitem>

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</varlistentry>

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<term><option>--config-file

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<para>

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Specify a different file to read additional options from.

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See <xref linkend="files"/>. Other command line options

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will override options specified in the file.

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</para>

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</listitem>

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</varlistentry>

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<term><option>--debug</option></term>

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<para>

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Enable debug mode. This will enable a lot of output to

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standard error about what the program is doing. The

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program will still perform all other functions normally.

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The default is to <emphasis>not</emphasis> run in debug

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mode.

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</para>

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<para>

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The plugins will <emphasis>not</emphasis> be affected by

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this option. Use

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<userinput><option>--global-options=--debug</option></userinput>

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if complete debugging eruption is desired.

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</para>

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</listitem>

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</varlistentry>

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<para>

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Gives a help message about options and their meanings.

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</para>

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</listitem>

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</varlistentry>

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<term><option>--usage</option></term>

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<para>

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Gives a short usage message.

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</para>

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</listitem>

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</varlistentry>

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<term><option>--version</option></term>

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<para>

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Prints the program version.

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</para>

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</listitem>

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</varlistentry>

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</variablelist>

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</refsect1>

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<title>OVERVIEW</title>

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<xi:include href="overview.xml"/>

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<para>

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This program will run on the client side in the initial

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<acronym>RAM</acronym> disk environment, and is responsible for

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getting a password. It does this by running plugins, one of

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which will normally be the actual client program communicating

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with the server.

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</para>

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</refsect1>

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<title>PLUGINS</title>

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<para>

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This program will get a password by running a number of

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<firstterm>plugins</firstterm>, which are simply executable

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programs in a directory in the initial <acronym>RAM</acronym>

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disk environment. The default directory is

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<filename>/lib/mandos/plugins.d</filename>, but this can be

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changed with the <option>--plugin-dir</option> option. The

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plugins are started in parallel, and the first plugin to output

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a password <emphasis>and</emphasis> exit with a successful exit

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code will make this plugin-runner output the password from that

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plugin, stop any other plugins, and exit.

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</para>

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407

408

<title>WRITING PLUGINS</title>

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<para>

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A plugin is simply a program which prints a password to its

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standard output and then exits with a successful (zero) exit

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status. If the exit status is not zero, any output on

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standard output will be ignored by the plugin runner. Any

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output on its standard error channel will simply be passed to

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the standard error of the plugin runner, usually the system

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console.

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</para>

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<para>

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The plugin will run in the initial RAM disk environment, so

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care must be taken not to depend on any files or running

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services not available there.

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</para>

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<para>

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The plugin must exit cleanly and free all allocated resources

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upon getting the TERM signal, since this is what the plugin

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runner uses to stop all other plugins when one plugin has

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output a password and exited cleanly.

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</para>

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<para>

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The plugin must not use resources, like for instance reading

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from the standard input, without knowing that no other plugins

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are also using it.

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</para>

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<para>

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It is useful, but not required, for the plugin to take the

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<option>--debug</option> option.

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</para>

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</refsect2>

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</refsect1>

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<title>FALLBACK</title>

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<para>

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If no plugins succeed, this program will, as a fallback, ask for

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a password on the console using <citerefentry><refentrytitle

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>getpass</refentrytitle><manvolnum>3</manvolnum></citerefentry>,

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and output it. This is not meant to be the normal mode of

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operation, as there is a separate plugin for getting a password

449

from the console.

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</para>

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</refsect1>

452

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<title>EXIT STATUS</title>

455

<para>

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Exit status of this program is zero if no errors were

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encountered, and otherwise not. The fallback (see <xref

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linkend="fallback"/>) may or may not have succeeded in either

459

case.

460

</para>

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</refsect1>

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<title>ENVIRONMENT</title>

465

<para>

466

This program does not use any environment variables itself, it

467

only passes on its environment to all the plugins. The

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environment passed to plugins can be modified using the

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<option>--global-env</option> and <option>--env-for</option>

470

optins.

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</para>

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</refsect1>

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475

<title>FILES</title>

476

<para>

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<term><filename

480

>/conf/conf.d/mandos/plugin-runner.conf</filename></term>

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<para>

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Since this program will be run as a keyscript, there is

484

little to no opportunity to pass command line arguments

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to it. Therefore, it will <emphasis>also</emphasis>

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read this file and use its contents as

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whitespace-separated command line options. Also,

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everything from a <quote>#</quote> character to the end

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of a line is ignored.

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</para>

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<para>

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This program is meant to run in the initial RAM disk

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environment, so that is where this file is assumed to

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exist. The file does not need to exist in the normal

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file system.

496

</para>

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<para>

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This file will be processed <emphasis>before</emphasis>

499

the normal command line options, so the latter can

500

override the former, if need be.

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</para>

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<para>

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This file name is the default; the file to read for

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arguments can be changed using the

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<option>--config-file</option> option.

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</para>

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</listitem>

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</varlistentry>

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</variablelist>

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</para>

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</refsect1>

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<title>EXAMPLE</title>

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<para>

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Normal invocation needs no options:

524

</para>

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<para>

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<userinput>&COMMANDNAME;</userinput>

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</para>

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</informalexample>

529

530

<para>

531

Run the program, but not the plugins, in debug mode:

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</para>

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<para>

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<userinput>&COMMANDNAME; --debug</userinput>

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</para>

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</informalexample>

540

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<para>

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Run all plugins, but run the <quote>foo</quote> plugin in

543

debug mode:

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</para>

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<para>

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<userinput>&COMMANDNAME; --options-for=foo:--debug</userinput>

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</para>

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</informalexample>

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<para>

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Run all plugins, but not the program, in debug mode:

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</para>

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<para>

557

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<userinput>&COMMANDNAME; --global-options=--debug</userinput>

560

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</para>

562

</informalexample>

563

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<para>

565

Run plugins from a different directory and add a special

566

option to the <citerefentry><refentrytitle

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>password-request</refentrytitle>

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<manvolnum>8mandos</manvolnum></citerefentry> plugin:

569

</para>

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<para>

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<userinput>&COMMANDNAME; --plugin-dir=plugins.d --options-for=password-request:--keydir=keydir</userinput>

574

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</para>

576

</informalexample>

577

</refsect1>

578

579

<title>SECURITY</title>

580

<para>

581

This program will, when starting, try to switch to another user.

582

If it is started as root, it will succeed, and will by default

583

switch to user and group 65534, which are assumed to be

584

non-privileged. This user and group is then what all plugins

585

will be started as. Therefore, the only way to run a plugin as

586

a privileged user is to have the set-user-ID or set-group-ID bit

587

set on the plugin executable files (see <citerefentry>

588

<refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum>

589

</citerefentry>).

590

</para>

591

<para>

592

If this program is used as a keyscript in <citerefentry

593

><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum>

594

</citerefentry>, there is a risk that if this program fails to

595

work, there might be no way to boot the system except for

596

booting from another media and editing the initial RAM disk

597

image to not run this program. This is, however, unlikely,

598

since the <citerefentry><refentrytitle

599

>password-prompt</refentrytitle><manvolnum>8mandos</manvolnum>

600

</citerefentry> plugin will read a password from the console in

601

case of failure of the other plugins, and this plugin runner

602

will also, in case of catastrophic failure, itself fall back to

603

asking and outputting a password on the console (see <xref

604

linkend="fallback"/>).

605

</para>

606

</refsect1>

607

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<para>

611

<citerefentry><refentrytitle>cryptsetup</refentrytitle>

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<manvolnum>8</manvolnum></citerefentry>,

613

<citerefentry><refentrytitle>crypttab</refentrytitle>

614

<manvolnum>5</manvolnum></citerefentry>,

615

<citerefentry><refentrytitle>execve</refentrytitle>

616

<manvolnum>2</manvolnum></citerefentry>,

617

<citerefentry><refentrytitle>mandos</refentrytitle>

618

<manvolnum>8</manvolnum></citerefentry>,

619

<citerefentry><refentrytitle>password-prompt</refentrytitle>

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<manvolnum>8mandos</manvolnum></citerefentry>,

621

<citerefentry><refentrytitle>password-request</refentrytitle>

622

<manvolnum>8mandos</manvolnum></citerefentry>

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</para>

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</refsect1>

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</refentry>

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