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  • Committer: Teddy Hogeborn
  • Date: 2018-08-19 01:35:11 UTC
  • Revision ID: teddy@recompile.se-20180819013511-cku25q9yeub3dnr0
Adapt to changes in cryptsetup; use "cryptroot-unlock" program

* Makefile (install-client-nokey): Also install new script files
  "mandos-to-cryptroot-unlock" and "initramfs-tools-script-stop".
* debian/mandos-client.dirs: Add
  "usr/share/initramfs-tools/scripts/local-premount".
* initramfs-tools-hook: Also copy "mandos-to-cryptroot-unlock".
* initramfs-tools-script: Only modify keyscript setting in cryptroot
  file if the file exists, otherwise start
  "mandos-to-cryptroot-unlock" in background.
* initramfs-tools-script-stop: New script to make sure plugin-runner
  has stopped before continuing.
* mandos-to-cryptroot-unlock: New script to run plugin-runner and feed
  any password it gets into the "cryptroot-unlock" program.

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plugins.d/usplash.xml
 
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<?xml version="1.0" encoding="UTF-8"?>
 
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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
 
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        "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
 
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<!ENTITY COMMANDNAME "usplash">
 
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<!ENTITY TIMESTAMP "2018-02-08">
 
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<!ENTITY % common SYSTEM "../common.ent">
 
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%common;
 
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]>
 
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<refentry xmlns:xi="http://www.w3.org/2001/XInclude">
 
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  <refentryinfo>
 
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    <title>Mandos Manual</title>
 
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    <!-- NWalsh’s docbook scripts use this to generate the footer: -->
 
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    <productname>Mandos</productname>
 
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    <productnumber>&version;</productnumber>
 
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    <date>&TIMESTAMP;</date>
 
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    <authorgroup>
 
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      <author>
 
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        <firstname>Björn</firstname>
 
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        <surname>Påhlsson</surname>
 
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        <address>
 
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          <email>belorn@recompile.se</email>
 
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        </address>
 
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      </author>
 
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      <author>
 
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        <firstname>Teddy</firstname>
 
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        <surname>Hogeborn</surname>
 
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        <address>
 
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          <email>teddy@recompile.se</email>
 
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        </address>
 
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      </author>
 
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    </authorgroup>
 
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    <copyright>
 
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      <year>2008</year>
 
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      <year>2009</year>
 
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      <year>2010</year>
 
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      <year>2011</year>
 
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      <year>2012</year>
 
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      <year>2013</year>
 
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      <year>2014</year>
 
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      <year>2015</year>
 
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      <year>2016</year>
 
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      <year>2017</year>
 
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      <year>2018</year>
 
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      <holder>Teddy Hogeborn</holder>
 
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      <holder>Björn Påhlsson</holder>
 
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    </copyright>
 
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    <xi:include href="../legalnotice.xml"/>
 
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  </refentryinfo>
 
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  <refmeta>
 
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    <refentrytitle>&COMMANDNAME;</refentrytitle>
 
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    <manvolnum>8mandos</manvolnum>
 
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  </refmeta>
 
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  <refnamediv>
 
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    <refname><command>&COMMANDNAME;</command></refname>
 
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    <refpurpose>Mandos plugin to use usplash to get a
 
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    password.</refpurpose>
 
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  </refnamediv>
 
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  <refsynopsisdiv>
 
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    <cmdsynopsis>
 
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      <command>&COMMANDNAME;</command>
 
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    </cmdsynopsis>
 
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  </refsynopsisdiv>
 
67
  
 
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  <refsect1 id="description">
 
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    <title>DESCRIPTION</title>
 
70
    <para>
 
71
      This program prompts for a password using <citerefentry>
 
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      <refentrytitle>usplash</refentrytitle><manvolnum>8</manvolnum>
 
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      </citerefentry> and outputs any given password to standard
 
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      output.  If no <citerefentry><refentrytitle
 
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      >usplash</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 
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      process can be found, this program will immediately exit with an
 
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      exit code indicating failure.
 
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    </para>
 
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    <para>
 
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      This program is not very useful on its own.  This program is
 
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      really meant to run as a plugin in the <application
 
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      >Mandos</application> client-side system, where it is used as a
 
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      fallback and alternative to retrieving passwords from a
 
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      <application >Mandos</application> server.
 
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    </para>
 
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    <para>
 
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      If this program is killed (presumably by
 
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      <citerefentry><refentrytitle>plugin-runner</refentrytitle>
 
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      <manvolnum>8mandos</manvolnum></citerefentry> because some other
 
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      plugin provided the password), it cannot tell <citerefentry>
 
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      <refentrytitle>usplash</refentrytitle><manvolnum>8</manvolnum>
 
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      </citerefentry> to abort requesting a password, because
 
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      <citerefentry><refentrytitle>usplash</refentrytitle>
 
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      <manvolnum>8</manvolnum></citerefentry> does not support this.
 
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      Therefore, this program will then <emphasis>kill</emphasis> the
 
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      running <citerefentry><refentrytitle>usplash</refentrytitle>
 
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      <manvolnum>8</manvolnum></citerefentry> process and start a
 
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      <emphasis>new</emphasis> one using the same command line
 
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      arguments as the old one was using.
 
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    </para>
 
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  </refsect1>
 
102
  
 
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  <refsect1 id="options">
 
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    <title>OPTIONS</title>
 
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    <para>
 
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      This program takes no options.
 
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    </para>
 
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  </refsect1>
 
109
  
 
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  <refsect1 id="exit_status">
 
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    <title>EXIT STATUS</title>
 
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    <para>
 
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      If exit status is 0, the output from the program is the password
 
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      as it was read.  Otherwise, if exit status is other than 0, the
 
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      program was interrupted or encountered an error, and any output
 
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      so far could be corrupt and/or truncated, and should therefore
 
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      be ignored.
 
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    </para>
 
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  </refsect1>
 
120
  
 
121
  <refsect1 id="environment">
 
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    <title>ENVIRONMENT</title>
 
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    <variablelist>
 
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      <varlistentry>
 
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        <term><envar>cryptsource</envar></term>
 
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        <term><envar>crypttarget</envar></term>
 
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        <listitem>
 
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          <para>
 
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            If set, these environment variables will be assumed to
 
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            contain the source device name and the target device
 
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            mapper name, respectively, and will be shown as part of
 
132
            the prompt.
 
133
        </para>
 
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        <para>
 
135
          These variables will normally be inherited from
 
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          <citerefentry><refentrytitle>plugin-runner</refentrytitle>
 
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          <manvolnum>8mandos</manvolnum></citerefentry>, which will
 
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          normally have inherited them from
 
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          <filename>/scripts/local-top/cryptroot</filename> in the
 
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          initial <acronym>RAM</acronym> disk environment, which will
 
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          have set them from parsing kernel arguments and
 
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          <filename>/conf/conf.d/cryptroot</filename> (also in the
 
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          initial RAM disk environment), which in turn will have been
 
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          created when the initial RAM disk image was created by
 
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          <filename
 
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          >/usr/share/initramfs-tools/hooks/cryptroot</filename>, by
 
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          extracting the information of the root file system from
 
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          <filename >/etc/crypttab</filename>.
 
149
        </para>
 
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        <para>
 
151
          This behavior is meant to exactly mirror the behavior of
 
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          <command>askpass</command>, the default password prompter.
 
153
        </para>
 
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        </listitem>
 
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      </varlistentry>
 
156
    </variablelist>
 
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  </refsect1>
 
158
  
 
159
  <refsect1 id="files">
 
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    <title>FILES</title>
 
161
    <variablelist>
 
162
      <varlistentry>
 
163
        <term><filename>/dev/.initramfs/usplash_fifo</filename></term>
 
164
        <listitem>
 
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          <para>
 
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            This is the <acronym>FIFO</acronym> to where this program
 
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            will write the commands for <citerefentry><refentrytitle
 
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            >usplash</refentrytitle><manvolnum>8</manvolnum>
 
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            </citerefentry>.  See <citerefentry><refentrytitle
 
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            >fifo</refentrytitle><manvolnum>7</manvolnum>
 
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            </citerefentry>.
 
172
          </para>
 
173
        </listitem>
 
174
      </varlistentry>
 
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      <varlistentry>
 
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        <term><filename>/dev/.initramfs/usplash_outfifo</filename></term>
 
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        <listitem>
 
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          <para>
 
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            This is the <acronym>FIFO</acronym> where this program
 
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            will read the password from <citerefentry><refentrytitle
 
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            >usplash</refentrytitle><manvolnum>8</manvolnum>
 
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            </citerefentry>.  See <citerefentry><refentrytitle
 
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            >fifo</refentrytitle><manvolnum>7</manvolnum>
 
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            </citerefentry>.
 
185
          </para>
 
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        </listitem>
 
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      </varlistentry>
 
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      <varlistentry>
 
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        <term><filename class="directory">/proc</filename></term>
 
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        <listitem>
 
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          <para>
 
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            To find the running <citerefentry><refentrytitle
 
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            >usplash</refentrytitle><manvolnum>8</manvolnum>
 
194
            </citerefentry>, this directory will be searched for
 
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            numeric entries which will be assumed to be directories.
 
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            In all those directories, the <filename>exe</filename> and
 
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            <filename>cmdline</filename> entries will be used to
 
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            determine the name of the running binary, effective user
 
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            and group <abbrev>ID</abbrev>, and the command line
 
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            arguments.  See <citerefentry><refentrytitle
 
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            >proc</refentrytitle><manvolnum>5</manvolnum>
 
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            </citerefentry>.
 
203
          </para>
 
204
        </listitem>
 
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      </varlistentry>
 
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      <varlistentry>
 
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        <term><filename>/sbin/usplash</filename></term>
 
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        <listitem>
 
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          <para>
 
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            This is the name of the binary which will be searched for
 
211
            in the process list.  See <citerefentry><refentrytitle
 
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            >usplash</refentrytitle><manvolnum>8</manvolnum>
 
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            </citerefentry>.
 
214
          </para>
 
215
        </listitem>
 
216
      </varlistentry>
 
217
    </variablelist>
 
218
  </refsect1>
 
219
  
 
220
  <refsect1 id="bugs">
 
221
    <title>BUGS</title>
 
222
    <para>
 
223
      Killing <citerefentry><refentrytitle>usplash</refentrytitle>
 
224
      <manvolnum>8</manvolnum></citerefentry> and starting a new one
 
225
      is ugly, but necessary as long as it does not support aborting a
 
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      password request.
 
227
    </para>
 
228
    <xi:include href="../bugs.xml"/>
 
229
  </refsect1>
 
230
  
 
231
  <refsect1 id="example">
 
232
    <title>EXAMPLE</title>
 
233
    <para>
 
234
      Note that normally, this program will not be invoked directly,
 
235
      but instead started by the Mandos <citerefentry><refentrytitle
 
236
      >plugin-runner</refentrytitle><manvolnum>8mandos</manvolnum>
 
237
      </citerefentry>.
 
238
    </para>
 
239
    <informalexample>
 
240
      <para>
 
241
        This program takes no options.
 
242
      </para>
 
243
      <para>
 
244
        <userinput>&COMMANDNAME;</userinput>
 
245
      </para>
 
246
    </informalexample>
 
247
  </refsect1>
 
248
  
 
249
  <refsect1 id="security">
 
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    <title>SECURITY</title>
 
251
    <para>
 
252
      If this program is killed by a signal, it will kill the process
 
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      <abbrev>ID</abbrev> which at the start of this program was
 
254
      determined to run <citerefentry><refentrytitle
 
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      >usplash</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 
256
      as root (see also <xref linkend="files"/>).  There is a very
 
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      slight risk that, in the time between those events, that process
 
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      <abbrev>ID</abbrev> was freed and then taken up by another
 
259
      process; the wrong process would then be killed.  Now, this
 
260
      program can only be killed by the user who started it; see
 
261
      <citerefentry><refentrytitle>plugin-runner</refentrytitle>
 
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      <manvolnum>8mandos</manvolnum></citerefentry>.  This program
 
263
      should therefore be started by a completely separate
 
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      non-privileged user, and no other programs should be allowed to
 
265
      run as that special user.  This means that it is not recommended
 
266
      to use the user "nobody" to start this program, as other
 
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      possibly less trusted programs could be running as "nobody", and
 
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      they would then be able to kill this program, triggering the
 
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      killing of the process <abbrev>ID</abbrev> which may or may not
 
270
      be <citerefentry><refentrytitle>usplash</refentrytitle>
 
271
      <manvolnum>8</manvolnum></citerefentry>.
 
272
    </para>
 
273
    <para>
 
274
      The only other thing that could be considered worthy of note is
 
275
      this:  This program is meant to be run by <citerefentry>
 
276
      <refentrytitle>plugin-runner</refentrytitle><manvolnum
 
277
      >8mandos</manvolnum></citerefentry>, and will, when run
 
278
      standalone, outside, in a normal environment, immediately output
 
279
      on its standard output any presumably secret password it just
 
280
      received.  Therefore, when running this program standalone
 
281
      (which should never normally be done), take care not to type in
 
282
      any real secret password by force of habit, since it would then
 
283
      immediately be shown as output.
 
284
    </para>
 
285
  </refsect1>
 
286
  
 
287
  <refsect1 id="see_also">
 
288
    <title>SEE ALSO</title>
 
289
    <para>
 
290
      <citerefentry><refentrytitle>intro</refentrytitle>
 
291
      <manvolnum>8mandos</manvolnum></citerefentry>,
 
292
      <citerefentry><refentrytitle>crypttab</refentrytitle>
 
293
      <manvolnum>5</manvolnum></citerefentry>,
 
294
      <citerefentry><refentrytitle>fifo</refentrytitle>
 
295
      <manvolnum>7</manvolnum></citerefentry>,
 
296
      <citerefentry><refentrytitle>plugin-runner</refentrytitle>
 
297
      <manvolnum>8mandos</manvolnum></citerefentry>,
 
298
      <citerefentry><refentrytitle>proc</refentrytitle>
 
299
      <manvolnum>5</manvolnum></citerefentry>,
 
300
      <citerefentry><refentrytitle>usplash</refentrytitle>
 
301
      <manvolnum>8</manvolnum></citerefentry>
 
302
    </para>
 
303
  </refsect1>
 
304
</refentry>
 
305
<!-- Local Variables: -->
 
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<!-- time-stamp-end: "[\"']>" -->
 
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<!-- End: -->