source: BOOK/final-system/common/shadow.xml @ 3373dd11

clfs-1.2clfs-2.1clfs-3.0.0-systemdclfs-3.0.0-sysvinitsystemdsysvinit
Last change on this file since 3373dd11 was 3373dd11, checked in by Jim Gifford <clfs@…>, 18 years ago

r668@server (orig r666): manuel | 2005-11-08 15:25:13 -0800
Removing SBUs and DUs. Chapter final-system, round 6.
  • Property mode set to 100644
File size: 18.3 KB
Line 
1<?xml version="1.0" encoding="ISO-8859-1"?>
2<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
3  "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [
4  <!ENTITY % general-entities SYSTEM "../../general.ent">
5  <!ENTITY % patches-entities SYSTEM "../../patches.ent">
6  %general-entities;
7  %patches-entities;
8]>
9
10<sect1 id="ch-system-shadow" role="wrap">
11  <?dbhtml filename="shadow.html"?>
12
13  <title>Shadow-&shadow-version;</title>
14
15  <indexterm zone="ch-system-shadow">
16    <primary sortas="a-Shadow">Shadow</primary>
17  </indexterm>
18
19  <sect2 role="package">
20    <title/>
21
22    <para>The Shadow package contains programs for handling passwords in a
23    secure way.</para>
24
25    <segmentedlist>
26      <segtitle>&dependencies;</segtitle>
27
28      <seglistitem>
29        <seg>Bash, Binutils, Bison, Coreutils, Diffutils, GCC, Gettext,
30        Glibc, Grep, Make, and Sed</seg>
31      </seglistitem>
32    </segmentedlist>
33
34  </sect2>
35
36  <sect2 role="installation">
37    <title>Installation of Shadow</title>
38
39    <note os="a">
40      <para>If you would like to enforce the use of strong passwords,
41      refer to <ulink url="&blfs-root;view/svn/postlfs/cracklib.html"/>
42      for installing Cracklib prior to building Shadow. Then add
43      <parameter>--with-libcrack</parameter> to the <command>configure</command>
44      command below.</para>
45    </note>
46
47    <para os="p1">Shadow has selinux, pam, and auditing defaulted to on. The
48     following patch properly fixes this issue:</para>
49
50<screen os="p2"><userinput>patch -Np1 -i ../&shadow-configure_fix-patch;</userinput></screen>
51
52    <para os="b">Prepare Shadow for compilation:</para>
53
54<screen><userinput>./configure --libdir=/lib --enable-shared</userinput></screen>
55
56    <variablelist os="c">
57      <title>The meaning of the new configure options:</title>
58
59      <varlistentry>
60        <term><parameter>to be done</parameter></term>
61        <listitem>
62          <para>to be done</para>
63        </listitem>
64      </varlistentry>
65
66    </variablelist>
67
68    <para os="d">Disable the installation of the <command>groups</command> program
69    and it's man page, as Coreutils provides a better version:</para>
70
71<screen os="e"><userinput>sed -i 's/groups$(EXEEXT) //' src/Makefile
72sed -i '/groups/d' man/Makefile</userinput></screen>
73
74    <para os="f">Compile the package:</para>
75
76<screen os="g"><userinput>make</userinput></screen>
77
78    <para os="h">Install the package:</para>
79
80<screen os="i"><userinput>make install</userinput></screen>
81
82    <para id="shadow-limits-login_access" os="j">Shadow uses two files to configure
83    authentication settings for the system. Install these two configuration
84    files:</para>
85
86    <indexterm zone="shadow-limits-login_access" os="k">
87      <primary sortas="e-/etc/limits">/etc/limits</primary>
88    </indexterm>
89
90    <indexterm zone="shadow-limits-login_access" os="l">
91      <primary sortas="e-/etc/login.access">/etc/login.access</primary>
92    </indexterm>
93
94<screen os="m"><userinput>cp etc/{limits,login.access} /etc</userinput></screen>
95
96    <para id="shadow-login_defs" os="n">Instead of using the default
97    <emphasis>crypt</emphasis> method, use the more secure
98    <emphasis>MD5</emphasis> method of password encryption, which also allows
99    passwords longer than 8 characters. It is also necessary to change the
100    obsolete <filename class="directory">/var/spool/mail</filename> location
101    for user mailboxes that Shadow uses by default to the <filename
102    class="directory">/var/mail</filename> location used currently. Both of
103    these can be accomplished by changing the relevant configuration file
104    while copying it to its destination:</para>
105
106    <indexterm zone="shadow-login_defs" os="o">
107      <primary sortas="e-/etc/login.defs">/etc/login.defs</primary>
108    </indexterm>
109
110    <note os="p">
111      <para>If you built Shadow with Cracklib support, insert the following into
112      the <command>sed</command> given below:</para>
113
114<screen><literal>-e 's@DICTPATH.*@DICTPATH\t/lib/cracklib/pw_dict@'</literal></screen>
115    </note>
116
117<screen os="q"><userinput>sed -e's@#MD5_CRYPT_ENAB.no@MD5_CRYPT_ENAB yes@' \
118    -e 's@/var/spool/mail@/var/mail@' \
119    etc/login.defs &gt; /etc/login.defs</userinput></screen>
120
121    <para os="r">Move a misplaced program to their proper location:</para>
122
123<screen os="s"><userinput>mv /usr/bin/passwd /bin</userinput></screen>
124
125    <para os="t">Move Shadow's dynamic libraries to a more appropriate
126    location:</para>
127
128<screen os="u"><userinput>mv /lib/libshadow.*a /usr/lib
129rm /lib/libshadow.so
130ln -sf ../../lib/libshadow.so.0 /usr/lib/libshadow.so</userinput></screen>
131
132    <para os="v">The <option>-D</option> option of the <command>useradd</command>
133    program requires the <filename class="directory">/etc/default</filename>
134    directory for it to work properly:</para>
135
136<screen os="w"><userinput>install -d /etc/default</userinput></screen>
137
138  </sect2>
139
140  <sect2 id="conf-shadow" role="configuration">
141    <title>Configuring Shadow</title>
142
143    <indexterm zone="conf-shadow">
144      <primary sortas="a-Shadow">Shadow</primary>
145      <secondary>configuring</secondary>
146    </indexterm>
147
148    <para>This package contains utilities to add, modify, and delete users and
149    groups; set and change their passwords; and perform other administrative
150    tasks. For a full explanation of what <emphasis>password shadowing</emphasis>
151    means, see the <filename>doc/HOWTO</filename> file within the unpacked source
152    tree. If using Shadow support, keep in mind that programs which need to
153    verify passwords (display managers, FTP programs, pop3 daemons, etc.) must
154    be Shadow-compliant. That is, they need to be able to work with shadowed
155    passwords.</para>
156
157    <para>To enable shadowed passwords, run the following command:</para>
158
159<screen><userinput>pwconv</userinput></screen>
160
161    <para>To enable shadowed group passwords, run:</para>
162
163<screen><userinput>grpconv</userinput></screen>
164
165    <para>Under normal circumstances, passwords will not have been created
166    yet. However, if returning to this section later to enable shadowing,
167    reset any current user passwords with the <command>passwd</command>
168    command or any group passwords with the <command>gpasswd</command>
169    command.</para>
170
171  </sect2>
172
173  <sect2 id="root-password" role="configuration">
174    <title>Setting the root password</title>
175
176    <para>Choose a password for user <systemitem
177    class="username">root</systemitem> and set it by running:</para>
178
179<screen><userinput>passwd root</userinput></screen>
180
181  </sect2>
182
183  <sect2 id="contents-shadow" role="content">
184    <title>Contents of Shadow</title>
185
186    <segmentedlist>
187      <segtitle>Installed programs</segtitle>
188      <segtitle>Installed libraries</segtitle>
189
190      <seglistitem>
191        <seg>chage, chfn, chpasswd, chsh, expiry, faillog, gpasswd, groupadd,
192        groupdel, groupmod, grpck, grpconv, grpunconv, lastlog, login,
193        logoutd, newgrp, newusers, passwd, pwck, pwconv, pwunconv,
194        sg (link to newgrp), useradd, userdel, usermod, vigr (link to vipw),
195        and vipw</seg>
196        <seg>libshadow.[a,so]</seg>
197      </seglistitem>
198    </segmentedlist>
199
200    <variablelist>
201      <bridgehead renderas="sect3">Short Descriptions</bridgehead>
202      <?dbfo list-presentation="list"?>
203      <?dbhtml list-presentation="table"?>
204
205      <varlistentry id="chage">
206        <term><command>chage</command></term>
207        <listitem>
208          <para>Used to change the maximum number of days between obligatory
209          password changes</para>
210          <indexterm zone="ch-system-shadow chage">
211            <primary sortas="b-chage">chage</primary>
212          </indexterm>
213        </listitem>
214      </varlistentry>
215
216      <varlistentry id="chfn">
217        <term><command>chfn</command></term>
218        <listitem>
219          <para>Used to change a user's full name and other information</para>
220          <indexterm zone="ch-system-shadow chfn">
221            <primary sortas="b-chfn">chfn</primary>
222          </indexterm>
223        </listitem>
224      </varlistentry>
225
226      <varlistentry id="chpasswd">
227        <term><command>chpasswd</command></term>
228        <listitem>
229          <para>Used to update the passwords of an entire series of user
230          accounts</para>
231          <indexterm zone="ch-system-shadow chpasswd">
232            <primary sortas="b-chpasswd">chpasswd</primary>
233          </indexterm>
234        </listitem>
235      </varlistentry>
236
237      <varlistentry id="chsh">
238        <term><command>chsh</command></term>
239        <listitem>
240          <para>Used to change a user's default login shell</para>
241          <indexterm zone="ch-system-shadow chsh">
242            <primary sortas="b-chsh">chsh</primary>
243          </indexterm>
244        </listitem>
245      </varlistentry>
246
247      <varlistentry id="expiry">
248        <term><command>expiry</command></term>
249        <listitem>
250          <para>Checks and enforces the current password expiration policy</para>
251          <indexterm zone="ch-system-shadow expiry">
252            <primary sortas="b-expiry">expiry</primary>
253          </indexterm>
254        </listitem>
255      </varlistentry>
256
257      <varlistentry id="faillog">
258        <term><command>faillog</command></term>
259        <listitem>
260          <para>Is used to examine the log of login failures, to set a maximum
261          number of failures before an account is blocked, or to reset the
262          failure count</para>
263          <indexterm zone="ch-system-shadow faillog">
264            <primary sortas="b-faillog">faillog</primary>
265          </indexterm>
266        </listitem>
267      </varlistentry>
268
269      <varlistentry id="gpasswd">
270        <term><command>gpasswd</command></term>
271        <listitem>
272          <para>Is used to add and delete members and administrators to
273          groups</para>
274          <indexterm zone="ch-system-shadow gpasswd">
275            <primary sortas="b-gpasswd">gpasswd</primary>
276          </indexterm>
277        </listitem>
278      </varlistentry>
279
280      <varlistentry id="groupadd">
281        <term><command>groupadd</command></term>
282        <listitem>
283          <para>Creates a group with the given name</para>
284          <indexterm zone="ch-system-shadow groupadd">
285            <primary sortas="b-groupadd">groupadd</primary>
286          </indexterm>
287        </listitem>
288      </varlistentry>
289
290      <varlistentry id="groupdel">
291        <term><command>groupdel</command></term>
292        <listitem>
293          <para>Deletes the group with the given name</para>
294          <indexterm zone="ch-system-shadow groupdel">
295            <primary sortas="b-groupdel">groupdel</primary>
296          </indexterm>
297        </listitem>
298      </varlistentry>
299
300      <varlistentry id="groupmod">
301        <term><command>groupmod</command></term>
302        <listitem>
303          <para>Is used to modify the given group's name or GID</para>
304          <indexterm zone="ch-system-shadow groupmod">
305            <primary sortas="b-groupmod">groupmod</primary>
306          </indexterm>
307        </listitem>
308      </varlistentry>
309
310      <varlistentry id="grpck">
311        <term><command>grpck</command></term>
312        <listitem>
313          <para>Verifies the integrity of the group files
314          <filename>/etc/group</filename> and
315          <filename>/etc/gshadow</filename></para>
316          <indexterm zone="ch-system-shadow grpck">
317            <primary sortas="b-grpck">grpck</primary>
318          </indexterm>
319        </listitem>
320      </varlistentry>
321
322      <varlistentry id="grpconv">
323        <term><command>grpconv</command></term>
324        <listitem>
325          <para>Creates or updates the shadow group file from the normal
326          group file</para>
327          <indexterm zone="ch-system-shadow grpconv">
328            <primary sortas="b-grpconv">grpconv</primary>
329          </indexterm>
330        </listitem>
331      </varlistentry>
332
333      <varlistentry id="grpunconv">
334        <term><command>grpunconv</command></term>
335        <listitem>
336          <para>Updates <filename>/etc/group</filename> from
337          <filename>/etc/gshadow</filename> and then deletes the latter</para>
338          <indexterm zone="ch-system-shadow grpunconv">
339            <primary sortas="b-grpunconv">grpunconv</primary>
340          </indexterm>
341        </listitem>
342      </varlistentry>
343
344      <varlistentry id="lastlog">
345        <term><command>lastlog</command></term>
346        <listitem>
347          <para>Reports the most recent login of all users or of a
348          given user</para>
349          <indexterm zone="ch-system-shadow lastlog">
350            <primary sortas="b-lastlog">lastlog</primary>
351          </indexterm>
352        </listitem>
353      </varlistentry>
354
355      <varlistentry id="login">
356        <term><command>login</command></term>
357        <listitem>
358          <para>Is used by the system to let users sign on</para>
359          <indexterm zone="ch-system-shadow login">
360            <primary sortas="b-login">login</primary>
361          </indexterm>
362        </listitem>
363      </varlistentry>
364
365      <varlistentry id="logoutd">
366        <term><command>logoutd</command></term>
367        <listitem>
368          <para>Is a daemon used to enforce restrictions on log-on time
369          and ports</para>
370          <indexterm zone="ch-system-shadow logoutd">
371            <primary sortas="b-logoutd">logoutd</primary>
372          </indexterm>
373        </listitem>
374      </varlistentry>
375
376      <varlistentry id="newgrp">
377        <term><command>newgrp</command></term>
378        <listitem>
379          <para>Is used to change the current GID during a login session</para>
380          <indexterm zone="ch-system-shadow newgrp">
381            <primary sortas="b-newgrp">newgrp</primary>
382          </indexterm>
383        </listitem>
384      </varlistentry>
385
386      <varlistentry id="newusers">
387        <term><command>newusers</command></term>
388        <listitem>
389          <para>Is used to create or update an entire series of user
390          accounts</para>
391          <indexterm zone="ch-system-shadow newusers">
392            <primary sortas="b-newusers">newusers</primary>
393          </indexterm>
394        </listitem>
395      </varlistentry>
396
397      <varlistentry id="passwd">
398        <term><command>passwd</command></term>
399        <listitem>
400          <para>Is used to change the password for a user or group account</para>
401          <indexterm zone="ch-system-shadow passwd">
402            <primary sortas="b-passwd">passwd</primary>
403          </indexterm>
404        </listitem>
405      </varlistentry>
406
407      <varlistentry id="pwck">
408        <term><command>pwck</command></term>
409        <listitem>
410          <para>Verifies the integrity of the password files
411          <filename>/etc/passwd</filename> and
412          <filename>/etc/shadow</filename></para>
413          <indexterm zone="ch-system-shadow pwck">
414            <primary sortas="b-pwck">pwck</primary>
415          </indexterm>
416        </listitem>
417      </varlistentry>
418
419      <varlistentry id="pwconv">
420        <term><command>pwconv</command></term>
421        <listitem>
422          <para>Creates or updates the shadow password file from the normal
423          password file</para>
424          <indexterm zone="ch-system-shadow pwconv">
425            <primary sortas="b-pwconv">pwconv</primary>
426          </indexterm>
427        </listitem>
428      </varlistentry>
429
430      <varlistentry id="pwunconv">
431        <term><command>pwunconv</command></term>
432        <listitem>
433          <para>Updates <filename>/etc/passwd</filename> from
434          <filename>/etc/shadow</filename> and then deletes the latter</para>
435          <indexterm zone="ch-system-shadow pwunconv">
436            <primary sortas="b-pwunconv">pwunconv</primary>
437          </indexterm>
438        </listitem>
439      </varlistentry>
440
441      <varlistentry id="sg">
442        <term><command>sg</command></term>
443        <listitem>
444          <para>Executes a given command while the user's GID
445          is set to that of the given group</para>
446          <indexterm zone="ch-system-shadow sg">
447            <primary sortas="b-sg">sg</primary>
448          </indexterm>
449        </listitem>
450      </varlistentry>
451
452      <varlistentry id="su">
453        <term><command>su</command></term>
454        <listitem>
455          <para>Runs a shell with substitute user and group IDs</para>
456          <indexterm zone="ch-system-shadow su">
457            <primary sortas="b-su">su</primary>
458          </indexterm>
459        </listitem>
460      </varlistentry>
461
462      <varlistentry id="useradd">
463        <term><command>useradd</command></term>
464        <listitem>
465          <para>Creates a new user with the given name, or updates the default
466          new-user information</para>
467          <indexterm zone="ch-system-shadow useradd">
468            <primary sortas="b-useradd">useradd</primary>
469          </indexterm>
470        </listitem>
471      </varlistentry>
472
473      <varlistentry id="userdel">
474        <term><command>userdel</command></term>
475        <listitem>
476          <para>Deletes the given user account</para>
477          <indexterm zone="ch-system-shadow userdel">
478            <primary sortas="b-userdel">userdel</primary>
479          </indexterm>
480        </listitem>
481      </varlistentry>
482
483      <varlistentry id="usermod">
484        <term><command>usermod</command></term>
485        <listitem>
486          <para>Is used to modify the given user's login name, User
487          Identification (UID), shell, initial group, home directory, etc.</para>
488          <indexterm zone="ch-system-shadow usermod">
489            <primary sortas="b-usermod">usermod</primary>
490          </indexterm>
491        </listitem>
492      </varlistentry>
493
494      <varlistentry id="vigr">
495        <term><command>vigr</command></term>
496        <listitem>
497          <para>Edits the <filename>/etc/group</filename> or
498          <filename>/etc/gshadow</filename> files</para>
499          <indexterm zone="ch-system-shadow vigr">
500            <primary sortas="b-vigr">vigr</primary>
501          </indexterm>
502        </listitem>
503      </varlistentry>
504
505      <varlistentry id="vipw">
506        <term><command>vipw</command></term>
507        <listitem>
508          <para>Edits the <filename>/etc/passwd</filename> or
509          <filename>/etc/shadow</filename> files</para>
510          <indexterm zone="ch-system-shadow vipw">
511            <primary sortas="b-vipw">vipw</primary>
512          </indexterm>
513        </listitem>
514      </varlistentry>
515
516      <varlistentry id="libshadow">
517        <term><filename class="libraryfile">libshadow</filename></term>
518        <listitem>
519          <para>Contains functions used by most programs in this package</para>
520          <indexterm zone="ch-system-shadow libshadow">
521            <primary sortas="c-libshadow">libshadow</primary>
522          </indexterm>
523        </listitem>
524      </varlistentry>
525
526    </variablelist>
527
528  </sect2>
529
530</sect1>
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