source: BOOK/final-system/common/shadow.xml @ 3c5b24c

clfs-1.2clfs-2.1clfs-3.0.0-systemdclfs-3.0.0-sysvinitsystemdsysvinit
Last change on this file since 3c5b24c was 3c5b24c, checked in by Joe Ciccone <jciccone@…>, 16 years ago

Remove the reference to libshadow from the shadow page.
  • Property mode set to 100644
File size: 18.4 KB
Line 
1<?xml version="1.0" encoding="ISO-8859-1"?>
2<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4  <!ENTITY % general-entities SYSTEM "../../general.ent">
5  %general-entities;
6]>
7
8<sect1 id="ch-system-shadow" role="wrap">
9  <?dbhtml filename="shadow.html"?>
10
11  <title>Shadow-&shadow-version;</title>
12
13  <indexterm zone="ch-system-shadow">
14    <primary sortas="a-Shadow">Shadow</primary>
15  </indexterm>
16
17  <sect2 role="package">
18    <title/>
19
20    <para>The Shadow package contains programs for handling passwords in a
21    secure way.</para>
22
23  </sect2>
24
25  <sect2 role="installation">
26    <title>Installation of Shadow</title>
27
28    <note os="a">
29      <para>If you would like to enforce the use of strong passwords,
30      refer to <ulink url="&cblfs-root;index.php/Cracklib"/>
31      for installing Cracklib prior to building Shadow. Then add
32      <parameter>--with-libcrack</parameter> to the <command>configure</command>
33      command below.</para>
34    </note>
35
36    <para os="b">Prepare Shadow for compilation:</para>
37
38<screen os="c"><userinput>./configure --libdir=/lib --sysconfdir=/etc --enable-shared \
39    --without-libpam --without-audit --without-selinux</userinput></screen>
40
41<para os="d">The meaning of the configure options:</para>
42
43  <variablelist os="e">
44    <varlistentry>
45      <term><parameter>--sysconfdir=/etc</parameter></term>
46      <listitem><para>Tells Shadow to install its configuration files into
47      /etc, rather than /usr/etc.</para></listitem>
48    </varlistentry>
49    <varlistentry>
50      <term><parameter>--without-libpam</parameter></term>
51      <listitem><para>Support for Linux-PAM is enabled by default in Shadow,
52      however PAM is not installed on a base CLFS system, so this switch
53      disables PAM support in Shadow. For instructions to install PAM and
54      link Shadow to it, you can look at
55      <ulink url="&cblfs-root;index.php/Linux-PAM"/>.</para></listitem>
56    </varlistentry>
57    <varlistentry>
58      <term><parameter>--without-audit</parameter></term>
59      <listitem><para>Support for auditing is enabled by default, but a
60      library that it needs is not installed in a base CLFS system. This
61      switch disables auditing support.</para></listitem>
62    </varlistentry>
63    <varlistentry>
64      <term><parameter>--without-selinux</parameter></term>
65      <listitem><para>Support for selinux is enabled by default, but selinux
66      is not built in a base CLFS system and configure will fail without this
67      switch.</para></listitem>
68    </varlistentry>
69  </variablelist>
70
71    <para os="f">Disable the installation of the <command>groups</command>
72    program and its man pages, as Coreutils provides a better version:</para>
73
74<screen os="g"><userinput>sed -i 's/groups$(EXEEXT) //' src/Makefile
75find man -name Makefile -exec sed -i '/groups.1.xml/d' '{}' \;
76find man -name Makefile -exec sed -i 's/groups.1 //' '{}' \;</userinput></screen>
77
78    <para os="h">Compile the package:</para>
79
80<screen os="i"><userinput>make</userinput></screen>
81
82    <para os="j">This package does not come with a test suite.</para>
83
84    <para os="k">Install the package:</para>
85
86<screen os="l"><userinput>make install</userinput></screen>
87
88    <para os="m" id="shadow-login_defs">Instead of using the default
89    <emphasis>crypt</emphasis> method, use the more secure
90    <emphasis>MD5</emphasis> method of password encryption, which also allows
91    passwords longer than 8 characters. It is also necessary to change the
92    obsolete <filename class="directory">/var/spool/mail</filename> location
93    for user mailboxes that Shadow uses by default to the <filename
94    class="directory">/var/mail</filename> location used currently. Use the
95    following sed command to make these changes to the appropriate
96    configuration file:</para>
97
98    <indexterm os="n" zone="shadow-login_defs">
99      <primary sortas="e-/etc/login.defs">/etc/login.defs</primary>
100    </indexterm>
101
102<screen os="s"><userinput>sed -i /etc/login.defs \
103    -e 's@#MD5_CRYPT_ENAB.no@MD5_CRYPT_ENAB yes@' \
104    -e 's@/var/spool/mail@/var/mail@'</userinput></screen>
105
106    <note os="t">
107      <para>If you built Shadow with Cracklib support, execute
108      this <command>sed</command> to correct the path to the Cracklib
109      dictionary:</para>
110
111<screen role="nodump"><userinput>sed -i 's@DICTPATH.*@DICTPATH\t/lib/cracklib/pw_dict@' /etc/login.defs</userinput></screen>
112    </note>
113
114    <para os="u">Move a misplaced program to its proper location:</para>
115
116<screen os="v"><userinput>mv -v /usr/bin/passwd /bin</userinput></screen>
117
118  </sect2>
119
120  <sect2 id="conf-shadow" role="configuration">
121    <title>Configuring Shadow</title>
122
123    <indexterm zone="conf-shadow">
124      <primary sortas="a-Shadow">Shadow</primary>
125      <secondary>configuring</secondary>
126    </indexterm>
127
128    <para>This package contains utilities to add, modify, and delete users and
129    groups; set and change their passwords; and perform other administrative
130    tasks. For a full explanation of what <emphasis>password shadowing</emphasis>
131    means, see the <filename>doc/HOWTO</filename> file within the unpacked source
132    tree. If using Shadow support, keep in mind that programs which need to
133    verify passwords (display managers, FTP programs, pop3 daemons, etc.) must
134    be Shadow-compliant. That is, they need to be able to work with shadowed
135    passwords.</para>
136
137    <para>To enable shadowed passwords, run the following command:</para>
138
139<screen><userinput>pwconv</userinput></screen>
140
141    <para>To enable shadowed group passwords, run:</para>
142
143<screen role="nodump"><userinput>grpconv</userinput></screen>
144
145    <para>To view or change the default settings for new user accounts that
146    you create, you can edit <filename>/etc/default/useradd</filename>. See
147    <command>man useradd</command> or
148    <ulink url="&cblfs-root;index.php/Configuring_for_Adding_Users"/> for more
149    information.</para>
150
151  </sect2>
152
153  <sect2 id="root-password" role="configuration">
154    <title>Setting the root password</title>
155
156    <para>Choose a password for user <systemitem
157    class="username">root</systemitem> and set it by running:</para>
158
159<screen role="nodump"><userinput>passwd root</userinput></screen>
160
161  </sect2>
162
163  <sect2 id="contents-shadow" role="content">
164    <title>Contents of Shadow</title>
165
166    <segmentedlist>
167      <segtitle>Installed programs</segtitle>
168      <segtitle>Installed libraries</segtitle>
169
170      <seglistitem>
171        <seg>chage, chfn, chpasswd, chgpasswd, chsh, expiry, faillog, gpasswd,
172        groupadd, groupdel, groupmod, grpck, grpconv, grpunconv, lastlog,
173        login, logoutd, newgrp, newusers, nologin, passwd, pwck, pwconv,
174        pwunconv, sg (link to newgrp), useradd, userdel, usermod,
175        vigr (link to vipw), and vipw</seg>
176        <seg>libshadow.[a,so]</seg>
177      </seglistitem>
178    </segmentedlist>
179
180    <variablelist>
181      <bridgehead renderas="sect3">Short Descriptions</bridgehead>
182      <?dbfo list-presentation="list"?>
183      <?dbhtml list-presentation="table"?>
184
185      <varlistentry id="chage">
186        <term><command>chage</command></term>
187        <listitem>
188          <para>Used to change the maximum number of days between obligatory
189          password changes</para>
190          <indexterm zone="ch-system-shadow chage">
191            <primary sortas="b-chage">chage</primary>
192          </indexterm>
193        </listitem>
194      </varlistentry>
195
196      <varlistentry id="chfn">
197        <term><command>chfn</command></term>
198        <listitem>
199          <para>Used to change a user's full name and other information</para>
200          <indexterm zone="ch-system-shadow chfn">
201            <primary sortas="b-chfn">chfn</primary>
202          </indexterm>
203        </listitem>
204      </varlistentry>
205
206      <varlistentry id="chgpasswd">
207        <term><command>chgpasswd</command></term>
208        <listitem>
209          <para>Used to update group passwords in batch mode</para>
210          <indexterm zone="ch-system-shadow chgpasswd">
211            <primary sortas="b-chgpasswd">chgpasswd</primary>
212          </indexterm>
213        </listitem>
214      </varlistentry>
215
216      <varlistentry id="chpasswd">
217        <term><command>chpasswd</command></term>
218        <listitem>
219          <para>Used to update the passwords of an entire series of user
220          accounts</para>
221          <indexterm zone="ch-system-shadow chpasswd">
222            <primary sortas="b-chpasswd">chpasswd</primary>
223          </indexterm>
224        </listitem>
225      </varlistentry>
226
227      <varlistentry id="chsh">
228        <term><command>chsh</command></term>
229        <listitem>
230          <para>Used to change a user's default login shell</para>
231          <indexterm zone="ch-system-shadow chsh">
232            <primary sortas="b-chsh">chsh</primary>
233          </indexterm>
234        </listitem>
235      </varlistentry>
236
237      <varlistentry id="expiry">
238        <term><command>expiry</command></term>
239        <listitem>
240          <para>Checks and enforces the current password expiration policy</para>
241          <indexterm zone="ch-system-shadow expiry">
242            <primary sortas="b-expiry">expiry</primary>
243          </indexterm>
244        </listitem>
245      </varlistentry>
246
247      <varlistentry id="faillog">
248        <term><command>faillog</command></term>
249        <listitem>
250          <para>Is used to examine the log of login failures, to set a maximum
251          number of failures before an account is blocked, or to reset the
252          failure count</para>
253          <indexterm zone="ch-system-shadow faillog">
254            <primary sortas="b-faillog">faillog</primary>
255          </indexterm>
256        </listitem>
257      </varlistentry>
258
259      <varlistentry id="gpasswd">
260        <term><command>gpasswd</command></term>
261        <listitem>
262          <para>Is used to add and delete members and administrators to
263          groups</para>
264          <indexterm zone="ch-system-shadow gpasswd">
265            <primary sortas="b-gpasswd">gpasswd</primary>
266          </indexterm>
267        </listitem>
268      </varlistentry>
269
270      <varlistentry id="groupadd">
271        <term><command>groupadd</command></term>
272        <listitem>
273          <para>Creates a group with the given name</para>
274          <indexterm zone="ch-system-shadow groupadd">
275            <primary sortas="b-groupadd">groupadd</primary>
276          </indexterm>
277        </listitem>
278      </varlistentry>
279
280      <varlistentry id="groupdel">
281        <term><command>groupdel</command></term>
282        <listitem>
283          <para>Deletes the group with the given name</para>
284          <indexterm zone="ch-system-shadow groupdel">
285            <primary sortas="b-groupdel">groupdel</primary>
286          </indexterm>
287        </listitem>
288      </varlistentry>
289
290      <varlistentry id="groupmod">
291        <term><command>groupmod</command></term>
292        <listitem>
293          <para>Is used to modify the given group's name or GID</para>
294          <indexterm zone="ch-system-shadow groupmod">
295            <primary sortas="b-groupmod">groupmod</primary>
296          </indexterm>
297        </listitem>
298      </varlistentry>
299
300      <varlistentry id="grpck">
301        <term><command>grpck</command></term>
302        <listitem>
303          <para>Verifies the integrity of the group files
304          <filename>/etc/group</filename> and
305          <filename>/etc/gshadow</filename></para>
306          <indexterm zone="ch-system-shadow grpck">
307            <primary sortas="b-grpck">grpck</primary>
308          </indexterm>
309        </listitem>
310      </varlistentry>
311
312      <varlistentry id="grpconv">
313        <term><command>grpconv</command></term>
314        <listitem>
315          <para>Creates or updates the shadow group file from the normal
316          group file</para>
317          <indexterm zone="ch-system-shadow grpconv">
318            <primary sortas="b-grpconv">grpconv</primary>
319          </indexterm>
320        </listitem>
321      </varlistentry>
322
323      <varlistentry id="grpunconv">
324        <term><command>grpunconv</command></term>
325        <listitem>
326          <para>Updates <filename>/etc/group</filename> from
327          <filename>/etc/gshadow</filename> and then deletes the latter</para>
328          <indexterm zone="ch-system-shadow grpunconv">
329            <primary sortas="b-grpunconv">grpunconv</primary>
330          </indexterm>
331        </listitem>
332      </varlistentry>
333
334      <varlistentry id="lastlog">
335        <term><command>lastlog</command></term>
336        <listitem>
337          <para>Reports the most recent login of all users or of a
338          given user</para>
339          <indexterm zone="ch-system-shadow lastlog">
340            <primary sortas="b-lastlog">lastlog</primary>
341          </indexterm>
342        </listitem>
343      </varlistentry>
344
345      <varlistentry id="login">
346        <term><command>login</command></term>
347        <listitem>
348          <para>Is used by the system to let users sign on</para>
349          <indexterm zone="ch-system-shadow login">
350            <primary sortas="b-login">login</primary>
351          </indexterm>
352        </listitem>
353      </varlistentry>
354
355      <varlistentry id="logoutd">
356        <term><command>logoutd</command></term>
357        <listitem>
358          <para>Is a daemon used to enforce restrictions on log-on time
359          and ports</para>
360          <indexterm zone="ch-system-shadow logoutd">
361            <primary sortas="b-logoutd">logoutd</primary>
362          </indexterm>
363        </listitem>
364      </varlistentry>
365
366      <varlistentry id="newgrp">
367        <term><command>newgrp</command></term>
368        <listitem>
369          <para>Is used to change the current GID during a login session</para>
370          <indexterm zone="ch-system-shadow newgrp">
371            <primary sortas="b-newgrp">newgrp</primary>
372          </indexterm>
373        </listitem>
374      </varlistentry>
375
376      <varlistentry id="newusers">
377        <term><command>newusers</command></term>
378        <listitem>
379          <para>Is used to create or update an entire series of user
380          accounts</para>
381          <indexterm zone="ch-system-shadow newusers">
382            <primary sortas="b-newusers">newusers</primary>
383          </indexterm>
384        </listitem>
385      </varlistentry>
386
387      <varlistentry id="nologin">
388        <term><command>nologin</command></term>
389        <listitem>
390          <para>Displays a message that an account is not available. Designed
391          to be used as the default shell for accounts that have been
392          disabled</para>
393          <indexterm zone="ch-system-shadow nologin">
394            <primary sortas="b-nologin">nologin</primary>
395          </indexterm>
396        </listitem>
397      </varlistentry>
398
399      <varlistentry id="passwd">
400        <term><command>passwd</command></term>
401        <listitem>
402          <para>Is used to change the password for a user or group account</para>
403          <indexterm zone="ch-system-shadow passwd">
404            <primary sortas="b-passwd">passwd</primary>
405          </indexterm>
406        </listitem>
407      </varlistentry>
408
409      <varlistentry id="pwck">
410        <term><command>pwck</command></term>
411        <listitem>
412          <para>Verifies the integrity of the password files
413          <filename>/etc/passwd</filename> and
414          <filename>/etc/shadow</filename></para>
415          <indexterm zone="ch-system-shadow pwck">
416            <primary sortas="b-pwck">pwck</primary>
417          </indexterm>
418        </listitem>
419      </varlistentry>
420
421      <varlistentry id="pwconv">
422        <term><command>pwconv</command></term>
423        <listitem>
424          <para>Creates or updates the shadow password file from the normal
425          password file</para>
426          <indexterm zone="ch-system-shadow pwconv">
427            <primary sortas="b-pwconv">pwconv</primary>
428          </indexterm>
429        </listitem>
430      </varlistentry>
431
432      <varlistentry id="pwunconv">
433        <term><command>pwunconv</command></term>
434        <listitem>
435          <para>Updates <filename>/etc/passwd</filename> from
436          <filename>/etc/shadow</filename> and then deletes the latter</para>
437          <indexterm zone="ch-system-shadow pwunconv">
438            <primary sortas="b-pwunconv">pwunconv</primary>
439          </indexterm>
440        </listitem>
441      </varlistentry>
442
443      <varlistentry id="sg">
444        <term><command>sg</command></term>
445        <listitem>
446          <para>Executes a given command while the user's GID
447          is set to that of the given group</para>
448          <indexterm zone="ch-system-shadow sg">
449            <primary sortas="b-sg">sg</primary>
450          </indexterm>
451        </listitem>
452      </varlistentry>
453
454      <varlistentry id="su">
455        <term><command>su</command></term>
456        <listitem>
457          <para>Runs a shell with substitute user and group IDs</para>
458          <indexterm zone="ch-system-shadow su">
459            <primary sortas="b-su">su</primary>
460          </indexterm>
461        </listitem>
462      </varlistentry>
463
464      <varlistentry id="useradd">
465        <term><command>useradd</command></term>
466        <listitem>
467          <para>Creates a new user with the given name, or updates the default
468          new-user information</para>
469          <indexterm zone="ch-system-shadow useradd">
470            <primary sortas="b-useradd">useradd</primary>
471          </indexterm>
472        </listitem>
473      </varlistentry>
474
475      <varlistentry id="userdel">
476        <term><command>userdel</command></term>
477        <listitem>
478          <para>Deletes the given user account</para>
479          <indexterm zone="ch-system-shadow userdel">
480            <primary sortas="b-userdel">userdel</primary>
481          </indexterm>
482        </listitem>
483      </varlistentry>
484
485      <varlistentry id="usermod">
486        <term><command>usermod</command></term>
487        <listitem>
488          <para>Is used to modify the given user's login name, User
489          Identification (UID), shell, initial group, home directory, etc.</para>
490          <indexterm zone="ch-system-shadow usermod">
491            <primary sortas="b-usermod">usermod</primary>
492          </indexterm>
493        </listitem>
494      </varlistentry>
495
496      <varlistentry id="vigr">
497        <term><command>vigr</command></term>
498        <listitem>
499          <para>Edits the <filename>/etc/group</filename> or
500          <filename>/etc/gshadow</filename> files</para>
501          <indexterm zone="ch-system-shadow vigr">
502            <primary sortas="b-vigr">vigr</primary>
503          </indexterm>
504        </listitem>
505      </varlistentry>
506
507      <varlistentry id="vipw">
508        <term><command>vipw</command></term>
509        <listitem>
510          <para>Edits the <filename>/etc/passwd</filename> or
511          <filename>/etc/shadow</filename> files</para>
512          <indexterm zone="ch-system-shadow vipw">
513            <primary sortas="b-vipw">vipw</primary>
514          </indexterm>
515        </listitem>
516      </varlistentry>
517
518    </variablelist>
519
520  </sect2>
521
522</sect1>
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