/mandos/trunk

To get this branch, use:
bzr branch http://bzr.recompile.se/loggerhead/mandos/trunk

« back to all changes in this revision

Viewing changes to plugins.d/usplash.xml

  • Committer: Teddy Hogeborn
  • Date: 2008-08-31 13:55:04 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080831135504-2ka1cccglsghslxy
* plugin-runner.xml (/refentry/refentryinfo/copyright): Split
                                                        copyright
                                                        holders.
* plugins.d/password-request.xml (/refentry/refentryinfo/copyright):
                                 Split copyright holders.

Show diffs side-by-side

added added

removed removed

Lines of Context:
plugins.d/usplash.xml
1
 
<?xml version="1.0" encoding="UTF-8"?>
2
 
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3
 
        "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4
 
<!ENTITY COMMANDNAME "usplash">
5
 
<!ENTITY TIMESTAMP "2018-02-08">
6
 
<!ENTITY % common SYSTEM "../common.ent">
7
 
%common;
8
 
]>
9
 
 
10
 
<refentry xmlns:xi="http://www.w3.org/2001/XInclude">
11
 
  <refentryinfo>
12
 
    <title>Mandos Manual</title>
13
 
    <!-- NWalsh’s docbook scripts use this to generate the footer: -->
14
 
    <productname>Mandos</productname>
15
 
    <productnumber>&version;</productnumber>
16
 
    <date>&TIMESTAMP;</date>
17
 
    <authorgroup>
18
 
      <author>
19
 
        <firstname>Björn</firstname>
20
 
        <surname>Påhlsson</surname>
21
 
        <address>
22
 
          <email>belorn@recompile.se</email>
23
 
        </address>
24
 
      </author>
25
 
      <author>
26
 
        <firstname>Teddy</firstname>
27
 
        <surname>Hogeborn</surname>
28
 
        <address>
29
 
          <email>teddy@recompile.se</email>
30
 
        </address>
31
 
      </author>
32
 
    </authorgroup>
33
 
    <copyright>
34
 
      <year>2008</year>
35
 
      <year>2009</year>
36
 
      <year>2010</year>
37
 
      <year>2011</year>
38
 
      <year>2012</year>
39
 
      <year>2013</year>
40
 
      <year>2014</year>
41
 
      <year>2015</year>
42
 
      <year>2016</year>
43
 
      <year>2017</year>
44
 
      <year>2018</year>
45
 
      <holder>Teddy Hogeborn</holder>
46
 
      <holder>Björn Påhlsson</holder>
47
 
    </copyright>
48
 
    <xi:include href="../legalnotice.xml"/>
49
 
  </refentryinfo>
50
 
  
51
 
  <refmeta>
52
 
    <refentrytitle>&COMMANDNAME;</refentrytitle>
53
 
    <manvolnum>8mandos</manvolnum>
54
 
  </refmeta>
55
 
  
56
 
  <refnamediv>
57
 
    <refname><command>&COMMANDNAME;</command></refname>
58
 
    <refpurpose>Mandos plugin to use usplash to get a
59
 
    password.</refpurpose>
60
 
  </refnamediv>
61
 
  
62
 
  <refsynopsisdiv>
63
 
    <cmdsynopsis>
64
 
      <command>&COMMANDNAME;</command>
65
 
    </cmdsynopsis>
66
 
  </refsynopsisdiv>
67
 
  
68
 
  <refsect1 id="description">
69
 
    <title>DESCRIPTION</title>
70
 
    <para>
71
 
      This program prompts for a password using <citerefentry>
72
 
      <refentrytitle>usplash</refentrytitle><manvolnum>8</manvolnum>
73
 
      </citerefentry> and outputs any given password to standard
74
 
      output.  If no <citerefentry><refentrytitle
75
 
      >usplash</refentrytitle><manvolnum>8</manvolnum></citerefentry>
76
 
      process can be found, this program will immediately exit with an
77
 
      exit code indicating failure.
78
 
    </para>
79
 
    <para>
80
 
      This program is not very useful on its own.  This program is
81
 
      really meant to run as a plugin in the <application
82
 
      >Mandos</application> client-side system, where it is used as a
83
 
      fallback and alternative to retrieving passwords from a
84
 
      <application >Mandos</application> server.
85
 
    </para>
86
 
    <para>
87
 
      If this program is killed (presumably by
88
 
      <citerefentry><refentrytitle>plugin-runner</refentrytitle>
89
 
      <manvolnum>8mandos</manvolnum></citerefentry> because some other
90
 
      plugin provided the password), it cannot tell <citerefentry>
91
 
      <refentrytitle>usplash</refentrytitle><manvolnum>8</manvolnum>
92
 
      </citerefentry> to abort requesting a password, because
93
 
      <citerefentry><refentrytitle>usplash</refentrytitle>
94
 
      <manvolnum>8</manvolnum></citerefentry> does not support this.
95
 
      Therefore, this program will then <emphasis>kill</emphasis> the
96
 
      running <citerefentry><refentrytitle>usplash</refentrytitle>
97
 
      <manvolnum>8</manvolnum></citerefentry> process and start a
98
 
      <emphasis>new</emphasis> one using the same command line
99
 
      arguments as the old one was using.
100
 
    </para>
101
 
  </refsect1>
102
 
  
103
 
  <refsect1 id="options">
104
 
    <title>OPTIONS</title>
105
 
    <para>
106
 
      This program takes no options.
107
 
    </para>
108
 
  </refsect1>
109
 
  
110
 
  <refsect1 id="exit_status">
111
 
    <title>EXIT STATUS</title>
112
 
    <para>
113
 
      If exit status is 0, the output from the program is the password
114
 
      as it was read.  Otherwise, if exit status is other than 0, the
115
 
      program was interrupted or encountered an error, and any output
116
 
      so far could be corrupt and/or truncated, and should therefore
117
 
      be ignored.
118
 
    </para>
119
 
  </refsect1>
120
 
  
121
 
  <refsect1 id="environment">
122
 
    <title>ENVIRONMENT</title>
123
 
    <variablelist>
124
 
      <varlistentry>
125
 
        <term><envar>cryptsource</envar></term>
126
 
        <term><envar>crypttarget</envar></term>
127
 
        <listitem>
128
 
          <para>
129
 
            If set, these environment variables will be assumed to
130
 
            contain the source device name and the target device
131
 
            mapper name, respectively, and will be shown as part of
132
 
            the prompt.
133
 
        </para>
134
 
        <para>
135
 
          These variables will normally be inherited from
136
 
          <citerefentry><refentrytitle>plugin-runner</refentrytitle>
137
 
          <manvolnum>8mandos</manvolnum></citerefentry>, which will
138
 
          normally have inherited them from
139
 
          <filename>/scripts/local-top/cryptroot</filename> in the
140
 
          initial <acronym>RAM</acronym> disk environment, which will
141
 
          have set them from parsing kernel arguments and
142
 
          <filename>/conf/conf.d/cryptroot</filename> (also in the
143
 
          initial RAM disk environment), which in turn will have been
144
 
          created when the initial RAM disk image was created by
145
 
          <filename
146
 
          >/usr/share/initramfs-tools/hooks/cryptroot</filename>, by
147
 
          extracting the information of the root file system from
148
 
          <filename >/etc/crypttab</filename>.
149
 
        </para>
150
 
        <para>
151
 
          This behavior is meant to exactly mirror the behavior of
152
 
          <command>askpass</command>, the default password prompter.
153
 
        </para>
154
 
        </listitem>
155
 
      </varlistentry>
156
 
    </variablelist>
157
 
  </refsect1>
158
 
  
159
 
  <refsect1 id="files">
160
 
    <title>FILES</title>
161
 
    <variablelist>
162
 
      <varlistentry>
163
 
        <term><filename>/dev/.initramfs/usplash_fifo</filename></term>
164
 
        <listitem>
165
 
          <para>
166
 
            This is the <acronym>FIFO</acronym> to where this program
167
 
            will write the commands for <citerefentry><refentrytitle
168
 
            >usplash</refentrytitle><manvolnum>8</manvolnum>
169
 
            </citerefentry>.  See <citerefentry><refentrytitle
170
 
            >fifo</refentrytitle><manvolnum>7</manvolnum>
171
 
            </citerefentry>.
172
 
          </para>
173
 
        </listitem>
174
 
      </varlistentry>
175
 
      <varlistentry>
176
 
        <term><filename>/dev/.initramfs/usplash_outfifo</filename></term>
177
 
        <listitem>
178
 
          <para>
179
 
            This is the <acronym>FIFO</acronym> where this program
180
 
            will read the password from <citerefentry><refentrytitle
181
 
            >usplash</refentrytitle><manvolnum>8</manvolnum>
182
 
            </citerefentry>.  See <citerefentry><refentrytitle
183
 
            >fifo</refentrytitle><manvolnum>7</manvolnum>
184
 
            </citerefentry>.
185
 
          </para>
186
 
        </listitem>
187
 
      </varlistentry>
188
 
      <varlistentry>
189
 
        <term><filename class="directory">/proc</filename></term>
190
 
        <listitem>
191
 
          <para>
192
 
            To find the running <citerefentry><refentrytitle
193
 
            >usplash</refentrytitle><manvolnum>8</manvolnum>
194
 
            </citerefentry>, this directory will be searched for
195
 
            numeric entries which will be assumed to be directories.
196
 
            In all those directories, the <filename>exe</filename> and
197
 
            <filename>cmdline</filename> entries will be used to
198
 
            determine the name of the running binary, effective user
199
 
            and group <abbrev>ID</abbrev>, and the command line
200
 
            arguments.  See <citerefentry><refentrytitle
201
 
            >proc</refentrytitle><manvolnum>5</manvolnum>
202
 
            </citerefentry>.
203
 
          </para>
204
 
        </listitem>
205
 
      </varlistentry>
206
 
      <varlistentry>
207
 
        <term><filename>/sbin/usplash</filename></term>
208
 
        <listitem>
209
 
          <para>
210
 
            This is the name of the binary which will be searched for
211
 
            in the process list.  See <citerefentry><refentrytitle
212
 
            >usplash</refentrytitle><manvolnum>8</manvolnum>
213
 
            </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
226
 
      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">
250
 
    <title>SECURITY</title>
251
 
    <para>
252
 
      If this program is killed by a signal, it will kill the process
253
 
      <abbrev>ID</abbrev> which at the start of this program was
254
 
      determined to run <citerefentry><refentrytitle
255
 
      >usplash</refentrytitle><manvolnum>8</manvolnum></citerefentry>
256
 
      as root (see also <xref linkend="files"/>).  There is a very
257
 
      slight risk that, in the time between those events, that process
258
 
      <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>
262
 
      <manvolnum>8mandos</manvolnum></citerefentry>.  This program
263
 
      should therefore be started by a completely separate
264
 
      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
267
 
      possibly less trusted programs could be running as "nobody", and
268
 
      they would then be able to kill this program, triggering the
269
 
      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: -->
306
 
<!-- time-stamp-start: "<!ENTITY TIMESTAMP [\"']" -->
307
 
<!-- time-stamp-end: "[\"']>" -->
308
 
<!-- time-stamp-format: "%:y-%02m-%02d" -->
309
 
<!-- End: -->