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Viewing changes to dracut-module/password-agent.xml

  • Committer: Teddy Hogeborn
  • Date: 2016-03-17 20:40:55 UTC
  • Revision ID: teddy@recompile.se-20160317204055-bhsh5xsidq7w5cxu
Client: Fix plymouth agent; broken since 1.7.2.

Fix an very old memory bug in the plymouth agent (which has been
present since its apperance in version 1.2), but which was only
recently detected at run time due to the new -fsanitize=address
compile- time flag, which has been used since version 1.7.2.  This
detection of a memory access violation causes the program to abort,
making the Plymouth graphical boot system unable to accept interactive
input of passwords when using the Mandos client.

* plugins.d/plymouth.c (exec_and_wait): Fix memory allocation bug when
  allocating new_argv.  Also tolerate a zero-length argv.

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dracut-module/password-agent.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"
3
 
        "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4
 
<!ENTITY COMMANDNAME "password-agent">
5
 
<!ENTITY TIMESTAMP "2019-07-24">
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>2019</year>
35
 
      <holder>Teddy Hogeborn</holder>
36
 
      <holder>Björn Påhlsson</holder>
37
 
    </copyright>
38
 
    <xi:include href="../legalnotice.xml"/>
39
 
  </refentryinfo>
40
 
 
41
 
  <refmeta>
42
 
    <refentrytitle>&COMMANDNAME;</refentrytitle>
43
 
    <manvolnum>8mandos</manvolnum>
44
 
  </refmeta>
45
 
 
46
 
  <refnamediv>
47
 
    <refname><command>&COMMANDNAME;</command></refname>
48
 
    <refpurpose>
49
 
      Run Mandos client as a systemd password agent.
50
 
    </refpurpose>
51
 
  </refnamediv>
52
 
 
53
 
  <refsynopsisdiv>
54
 
    <cmdsynopsis>
55
 
      <command>&COMMANDNAME;</command>
56
 
      <arg><option>--agent-directory=<replaceable
57
 
      >DIRECTORY</replaceable></option></arg>
58
 
      <sbr/>
59
 
      <arg><option>--helper-directory=<replaceable
60
 
      >DIRECTORY</replaceable></option></arg>
61
 
      <sbr/>
62
 
      <!-- <arg><option>-\-plugin-helper-dir=<replaceable -->
63
 
      <!-- >DIRECTORY</replaceable></option></arg> -->
64
 
      <!-- <sbr/> -->
65
 
      <arg><option>--user=<replaceable
66
 
      >USERID</replaceable></option></arg>
67
 
      <sbr/>
68
 
      <!-- <arg><option>-\-userid=<replaceable -->
69
 
      <!-- >ID</replaceable></option></arg> -->
70
 
      <!-- <sbr/> -->
71
 
      <arg><option>--group=<replaceable
72
 
      >GROUPID</replaceable></option></arg>
73
 
      <sbr/>
74
 
      <!-- <arg><option>-\-groupid=<replaceable -->
75
 
      <!-- >ID</replaceable></option></arg> -->
76
 
      <!-- <sbr/> -->
77
 
      <arg>--</arg>
78
 
      <arg>
79
 
        <replaceable>MANDOS_CLIENT</replaceable>
80
 
        <group rep="repeat">
81
 
          <arg choice="plain"><replaceable>OPTIONS</replaceable></arg>
82
 
        </group>
83
 
      </arg>
84
 
    </cmdsynopsis>
85
 
    <cmdsynopsis>
86
 
      <command>&COMMANDNAME;</command>
87
 
      <arg choice="plain"><option>--test</option></arg>
88
 
    </cmdsynopsis>
89
 
    <cmdsynopsis>
90
 
      <command>&COMMANDNAME;</command>
91
 
      <group choice="req">
92
 
        <arg choice="plain"><option>--help</option></arg>
93
 
        <arg choice="plain"><option>-?</option></arg>
94
 
      </group>
95
 
    </cmdsynopsis>
96
 
    <cmdsynopsis>
97
 
      <command>&COMMANDNAME;</command>
98
 
      <arg choice="plain"><option>--usage</option></arg>
99
 
    </cmdsynopsis>
100
 
    <cmdsynopsis>
101
 
      <command>&COMMANDNAME;</command>
102
 
      <group choice="req">
103
 
        <arg choice="plain"><option>--version</option></arg>
104
 
        <arg choice="plain"><option>-V</option></arg>
105
 
      </group>
106
 
    </cmdsynopsis>
107
 
  </refsynopsisdiv>
108
 
 
109
 
  <refsect1 id="description">
110
 
    <title>DESCRIPTION</title>
111
 
    <para>
112
 
      <command>&COMMANDNAME;</command> is a program which is meant to
113
 
      be a <citerefentry><refentrytitle>systemd</refentrytitle>
114
 
      <manvolnum>1</manvolnum></citerefentry> <quote>Password
115
 
      Agent</quote> (See <ulink
116
 
      url="https://www.freedesktop.org/wiki/Software/systemd/PasswordAgents/"
117
 
      >Password Agents</ulink>).  The aim of this program is therefore
118
 
      to acquire and then send a password to some other program which
119
 
      will use the password to unlock the encrypted root disk.
120
 
    </para>
121
 
    <para>
122
 
      This program is not meant to be invoked directly, but can be in
123
 
      order to test it.
124
 
    </para>
125
 
  </refsect1>
126
 
 
127
 
  <refsect1 id="purpose">
128
 
    <title>PURPOSE</title>
129
 
    <para>
130
 
      The purpose of this is to enable <emphasis>remote and unattended
131
 
      rebooting</emphasis> of client host computer with an
132
 
      <emphasis>encrypted root file system</emphasis>.  See <xref
133
 
      linkend="overview"/> for details.
134
 
    </para>
135
 
  </refsect1>
136
 
 
137
 
  <refsect1>
138
 
    <title>OPTIONS</title>
139
 
    <variablelist>
140
 
 
141
 
      <varlistentry>
142
 
        <term><option>--agent-directory
143
 
        <replaceable>DIRECTORY</replaceable></option></term>
144
 
        <listitem>
145
 
          <para>
146
 
            Specify a different agent directory.  The default is
147
 
            <quote><filename class="directory"
148
 
            >/run/systemd/ask-password</filename ></quote> as per the
149
 
            <ulink
150
 
            url="https://www.freedesktop.org/wiki/Software/systemd/PasswordAgents/"
151
 
            >Password Agents</ulink> specification.
152
 
          </para>
153
 
        </listitem>
154
 
      </varlistentry>
155
 
 
156
 
      <varlistentry>
157
 
        <term><option>--helper-directory
158
 
        <replaceable>DIRECTORY</replaceable></option></term>
159
 
        <listitem>
160
 
          <para>
161
 
            Specify a different helper directory.  The default is
162
 
            <quote><filename class="directory"
163
 
                             >/lib/mandos/plugin-helpers</filename
164
 
                             ></quote>, which
165
 
            will exist in the initial <acronym>RAM</acronym> disk
166
 
            environment.  (This will simply be passed to the
167
 
            <replaceable>MANDOS_CLIENT</replaceable> program via the
168
 
            <envar>MANDOSPLUGINHELPERDIR</envar> environment variable.
169
 
            See
170
 
            <citerefentry><refentrytitle>mandos-client</refentrytitle
171
 
            ><manvolnum>8mandos</manvolnum></citerefentry>.)
172
 
          </para>
173
 
        </listitem>
174
 
      </varlistentry>
175
 
 
176
 
      <varlistentry>
177
 
        <term><option>--user
178
 
        <replaceable>USERID</replaceable></option></term>
179
 
        <listitem>
180
 
          <para>
181
 
            Change real user ID to <replaceable>USERID</replaceable>
182
 
            when running <replaceable>MANDOS_CLIENT</replaceable>.
183
 
            The default is 65534.  <emphasis>Note:</emphasis> This
184
 
            must be a number, not a name.
185
 
          </para>
186
 
        </listitem>
187
 
      </varlistentry>
188
 
 
189
 
      <varlistentry>
190
 
        <term><option>--group
191
 
        <replaceable>GROUPID</replaceable></option></term>
192
 
        <listitem>
193
 
          <para>
194
 
            Change real group ID to <replaceable>GROUPID</replaceable>
195
 
            when running <replaceable>MANDOS_CLIENT</replaceable>.
196
 
            The default is 65534.  <emphasis>Note:</emphasis> This
197
 
            must be a number, not a name.
198
 
          </para>
199
 
        </listitem>
200
 
      </varlistentry>
201
 
 
202
 
      <varlistentry>
203
 
        <term><replaceable>MANDOS_CLIENT</replaceable></term>
204
 
        <listitem>
205
 
          <para>
206
 
            This specifies the file name for
207
 
            <citerefentry><refentrytitle>mandos-client</refentrytitle
208
 
            ><manvolnum>8mandos</manvolnum></citerefentry>.  If the
209
 
            <quote><option>--</option></quote> option is given, any
210
 
            following options are passed to the <replaceable
211
 
            >MANDOS_CLIENT</replaceable> program.  The default is
212
 
            <quote><filename
213
 
            >/lib/mandos/plugins.d/mandos-client</filename ></quote>
214
 
            (which is the correct location for the initial
215
 
            <acronym>RAM</acronym> disk environment) without any
216
 
            options.
217
 
          </para>
218
 
        </listitem>
219
 
      </varlistentry>
220
 
 
221
 
      <varlistentry>
222
 
        <term><option>--help</option></term>
223
 
        <term><option>-?</option></term>
224
 
        <listitem>
225
 
          <para>
226
 
            Gives a help message about options and their meanings.
227
 
          </para>
228
 
        </listitem>
229
 
      </varlistentry>
230
 
 
231
 
      <varlistentry>
232
 
        <term><option>--test</option></term>
233
 
        <listitem>
234
 
          <para>
235
 
            Ignore normal operation; instead only run self-tests.
236
 
            Adding the <option>--help</option> option may show more
237
 
            options possible in combination with
238
 
            <option>--test</option>.
239
 
          </para>
240
 
        </listitem>
241
 
      </varlistentry>
242
 
 
243
 
      <varlistentry>
244
 
        <term><option>--usage</option></term>
245
 
        <listitem>
246
 
          <para>
247
 
            Gives a short usage message.
248
 
          </para>
249
 
        </listitem>
250
 
      </varlistentry>
251
 
 
252
 
      <varlistentry>
253
 
        <term><option>--version</option></term>
254
 
        <term><option>-V</option></term>
255
 
        <listitem>
256
 
          <para>
257
 
            Prints the program version.
258
 
          </para>
259
 
        </listitem>
260
 
      </varlistentry>
261
 
    </variablelist>
262
 
  </refsect1>
263
 
 
264
 
  <refsect1 id="overview">
265
 
    <title>OVERVIEW</title>
266
 
    <xi:include href="../overview.xml"/>
267
 
    <para>
268
 
      This program, &COMMANDNAME;, will run on the client side in the
269
 
      initial <acronym>RAM</acronym> disk environment, and is
270
 
      responsible for getting a password from the Mandos client
271
 
      program itself, and to send that password to whatever is
272
 
      currently asking for a password using the systemd <ulink
273
 
      url="https://www.freedesktop.org/wiki/Software/systemd/PasswordAgents/"
274
 
      >Password Agents</ulink> mechanism.
275
 
    </para>
276
 
    <para>To accomplish this, &COMMANDNAME; runs the
277
 
    <command>mandos-client</command> program (which is the actual
278
 
    client program communicating with the Mandos server) or,
279
 
    alternatively, any executable file specified as
280
 
    <replaceable>MANDOS_CLIENT</replaceable>, and, as soon as a
281
 
    password is acquired from the
282
 
    <replaceable>MANDOS_CLIENT</replaceable> program, sends that
283
 
    password (as per the <ulink
284
 
    url="https://www.freedesktop.org/wiki/Software/systemd/PasswordAgents/"
285
 
    >Password Agents</ulink> specification) to all currently
286
 
    unanswered password questions.
287
 
    </para>
288
 
    <para>
289
 
      This program should be started (normally as a systemd service,
290
 
      which in turn is normally started by a <citerefentry
291
 
      ><refentrytitle>systemd.path</refentrytitle>
292
 
      <manvolnum>5</manvolnum></citerefentry> file) as a reaction to
293
 
      files named <quote><filename>ask.<replaceable>xxxx</replaceable
294
 
      ></filename></quote> appearing in the agent directory
295
 
      <quote><filename
296
 
      class="directory">/run/systemd/ask-password</filename></quote>
297
 
      (or the directory specified by
298
 
      <option>--agent-directory</option>).
299
 
    </para>
300
 
  </refsect1>
301
 
 
302
 
  <refsect1 id="exit_status">
303
 
    <title>EXIT STATUS</title>
304
 
    <para>
305
 
      Exit status of this program is zero if no errors were
306
 
      encountered, and otherwise not.
307
 
    </para>
308
 
  </refsect1>
309
 
 
310
 
  <refsect1 id="environment">
311
 
    <title>ENVIRONMENT</title>
312
 
    <para>
313
 
      This program does not use any environment variables itself, it
314
 
      only passes on its environment to
315
 
      <replaceable>MANDOS_CLIENT</replaceable>.  Also, the
316
 
      <option>--helper-directory</option> option will affect the
317
 
      environment variable <envar>MANDOSPLUGINHELPERDIR</envar> for
318
 
      <replaceable>MANDOS_CLIENT</replaceable>.
319
 
    </para>
320
 
  </refsect1>
321
 
 
322
 
  <refsect1 id="files">
323
 
    <title>FILES</title>
324
 
    <para>
325
 
      <variablelist>
326
 
        <varlistentry>
327
 
          <term><filename class="directory"
328
 
                          >/run/systemd/ask-password</filename></term>
329
 
          <listitem>
330
 
            <para>
331
 
              The default directory to watch for password questions as
332
 
              per the <ulink
333
 
              url="https://www.freedesktop.org/wiki/Software/systemd/PasswordAgents/"
334
 
              >Password Agents</ulink> specification; can be changed
335
 
              by the <option>--agent-directory</option> option.
336
 
            </para>
337
 
          </listitem>
338
 
        </varlistentry>
339
 
        <varlistentry>
340
 
          <term><filename class="directory"
341
 
                          >/lib/mandos/plugin-helpers</filename
342
 
                          ></term>
343
 
          <listitem>
344
 
            <para>
345
 
              The helper directory as supplied to
346
 
              <replaceable>MANDOS_CLIENT</replaceable> via the
347
 
              <envar>MANDOSPLUGINHELPERDIR</envar> environment
348
 
              variable; can be changed by the
349
 
              <option>--helper-directory</option> option.
350
 
            </para>
351
 
          </listitem>
352
 
        </varlistentry>
353
 
      </variablelist>
354
 
    </para>
355
 
  </refsect1>
356
 
 
357
 
  <refsect1 id="bugs">
358
 
    <title>BUGS</title>
359
 
    <xi:include href="../bugs.xml"/>
360
 
  </refsect1>
361
 
 
362
 
  <refsect1 id="examples">
363
 
    <title>EXAMPLE</title>
364
 
    <informalexample>
365
 
      <para>
366
 
        Normal invocation needs no options:
367
 
      </para>
368
 
      <para>
369
 
        <userinput>&COMMANDNAME;</userinput>
370
 
      </para>
371
 
    </informalexample>
372
 
    <informalexample>
373
 
      <para>
374
 
        Run an alternative <replaceable>MANDOS_CLIENT</replaceable>
375
 
        program::
376
 
      </para>
377
 
      <para>
378
 
        <userinput>&COMMANDNAME; /usr/local/sbin/alternate</userinput>
379
 
      </para>
380
 
    </informalexample>
381
 
    <informalexample>
382
 
      <para>
383
 
        Use alternative locations for the helper directory and the
384
 
        Mandos client, and add extra options suitable for running in
385
 
        the normal file system:
386
 
      </para>
387
 
      <para>
388
 
        
389
 
        <!-- do not wrap this line -->
390
 
        <userinput>&COMMANDNAME; --helper-directory=/usr/lib/x86_64-linux-gnu/mandos/plugin-helpers -- /usr/lib/x86_64-linux-gnu/mandos/plugins.d/mandos-client --pubkey=/etc/keys/mandos/pubkey.txt --seckey=/etc/keys/mandos/seckey.txt --tls-pubkey=/etc/keys/mandos/tls-pubkey.pem --tls-privkey=/etc/keys/mandos/tls-privkey.pem</userinput>
391
 
        
392
 
      </para>
393
 
    </informalexample>
394
 
    <informalexample>
395
 
      <para>
396
 
        Use the default location for
397
 
        <citerefentry><refentrytitle>mandos-client</refentrytitle>
398
 
        <manvolnum>8mandos</manvolnum></citerefentry>, but add many
399
 
        options to it:
400
 
      </para>
401
 
      <para>
402
 
 
403
 
<!-- do not wrap this line -->
404
 
<userinput>&COMMANDNAME; -- /lib/mandos/mandos-client --pubkey=/etc/mandos/keys/pubkey.txt --seckey=/etc/mandos/keys/seckey.txt --tls-pubkey=/etc/mandos/keys/tls-pubkey.pem --tls-privkey=/etc/mandos/keys/tls-privkey.pem</userinput>
405
 
 
406
 
      </para>
407
 
    </informalexample>
408
 
    <informalexample>
409
 
      <para>
410
 
        Only run the self-tests:
411
 
      </para>
412
 
      <para>
413
 
        <userinput>&COMMANDNAME; --test</userinput>
414
 
      </para>
415
 
    </informalexample>
416
 
  </refsect1>
417
 
  <refsect1 id="security">
418
 
    <title>SECURITY</title>
419
 
    <para>
420
 
      This program will need to run as the root user in order to read
421
 
      the agent directory and the <quote><filename
422
 
      >ask.<replaceable>xxxx</replaceable></filename></quote> files
423
 
      there, and will, when starting the Mandos client program,
424
 
      require the ability to set the <quote>real</quote> user and
425
 
      group ids to another user, by default user and group 65534,
426
 
      which are assumed to be non-privileged.  This is done in order
427
 
      to match the expectations of <citerefentry><refentrytitle
428
 
      >mandos-client</refentrytitle><manvolnum>8mandos</manvolnum
429
 
      ></citerefentry>, which assumes that its executable file is
430
 
      owned by the root user and also has the set-user-ID bit set (see
431
 
      <citerefentry><refentrytitle>execve</refentrytitle><manvolnum
432
 
      >2</manvolnum></citerefentry>).
433
 
    </para>
434
 
  </refsect1>
435
 
 
436
 
  <refsect1 id="see_also">
437
 
    <title>SEE ALSO</title>
438
 
    <para>
439
 
      <citerefentry><refentrytitle>intro</refentrytitle>
440
 
      <manvolnum>8mandos</manvolnum></citerefentry>,
441
 
      <citerefentry><refentrytitle>mandos-client</refentrytitle>
442
 
      <manvolnum>8mandos</manvolnum></citerefentry>,
443
 
      <citerefentry><refentrytitle>systemd</refentrytitle>
444
 
      <manvolnum>1</manvolnum></citerefentry>,
445
 
    </para>
446
 
    <variablelist>
447
 
      <varlistentry>
448
 
        <term>
449
 
          <ulink
450
 
              url="https://www.freedesktop.org/wiki/Software/systemd/PasswordAgents/"
451
 
              >Password Agents</ulink>
452
 
        </term>
453
 
        <listitem>
454
 
          <para>
455
 
            The specification for systemd <quote>Password
456
 
            Agent</quote> programs, which
457
 
            <command>&COMMANDNAME;</command> follows.
458
 
          </para>
459
 
        </listitem>
460
 
      </varlistentry>
461
 
    </variablelist>
462
 
  </refsect1>
463
 
 
464
 
</refentry>
465
 
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