source: chapter06/shadow.xml@ 3fa7ca4

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Last change on this file since 3fa7ca4 was c466df68, checked in by Randy McMurchy <randy@…>, 16 years ago

Updated Shadow to 4.1.2.1

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@8614 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

  • Property mode set to 100644
File size: 21.5 KB
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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 <sect1info condition="script">
12 <productname>shadow</productname>
13 <productnumber>&shadow-version;</productnumber>
14 <address>&shadow-url;</address>
15 </sect1info>
16
17 <title>Shadow-&shadow-version;</title>
18
19 <indexterm zone="ch-system-shadow">
20 <primary sortas="a-Shadow">Shadow</primary>
21 </indexterm>
22
23 <sect2 role="package">
24 <title/>
25
26 <para>The Shadow package contains programs for handling passwords in a secure
27 way.</para>
28
29 <segmentedlist>
30 <segtitle>&buildtime;</segtitle>
31 <segtitle>&diskspace;</segtitle>
32
33 <seglistitem>
34 <seg>&shadow-ch6-sbu;</seg>
35 <seg>&shadow-ch6-du;</seg>
36 </seglistitem>
37 </segmentedlist>
38
39 </sect2>
40
41 <sect2 role="installation">
42 <title>Installation of Shadow</title>
43
44 <note>
45 <para>If you would like to enforce the use of strong passwords, refer to
46 <ulink url="&blfs-root;view/svn/postlfs/cracklib.html"/> for installing
47 CrackLib prior to building Shadow. Then add
48 <parameter>--with-libcrack</parameter> to the <command>configure</command>
49 command below.</para>
50 </note>
51
52 <!-- <para>Fix a bug in the <command>useradd</command> and
53 <command>usermod</command> programs which prevent them from accepting group
54 names rather than group ID numbers to the <option>-g</option> option:</para>
55
56<screen><userinput remap="pre">patch -Np1 -i ../&shadow-useradd-patch;</userinput></screen>
57 -->
58
59 <para>Disable the installation of the <command>groups</command> program
60 and its man pages, as Coreutils provides a better version:</para>
61
62<screen><userinput remap="configure">sed -i 's/groups$(EXEEXT) //' src/Makefile.in
63find man -name Makefile.in -exec sed -i 's/groups\.1 / /' {} \;</userinput></screen>
64
65 <para>Disable the installation of Chinese and Korean manual pages, since
66 Man-DB cannot format them properly:</para>
67
68<screen><userinput remap="configure">sed -i -e 's/ ko//' -e 's/ zh_CN zh_TW//' man/Makefile.in</userinput></screen>
69
70 <para>Shadow supplies other manual pages in a UTF-8 encoding. Man-DB
71 can display these in the recommended encodings by using the
72 <command>convert-mans</command> script which was installed during the
73 Man-DB package:</para>
74
75<screen><userinput remap="configure">for i in de es fi fr id it pt_BR; do
76 convert-mans UTF-8 ISO-8859-1 man/${i}/*.?
77done
78
79for i in cs hu pl; do
80 convert-mans UTF-8 ISO-8859-2 man/${i}/*.?
81done
82
83convert-mans UTF-8 EUC-JP man/ja/*.?
84convert-mans UTF-8 KOI8-R man/ru/*.?
85convert-mans UTF-8 ISO-8859-9 man/tr/*.?</userinput></screen>
86
87 <para id="shadow-login_defs">Instead of using the default
88 <emphasis>crypt</emphasis> method, use the more secure
89 <emphasis>MD5</emphasis> method of password encryption, which also allows
90 passwords longer than 8 characters. It is also necessary to change the
91 obsolete <filename class="directory">/var/spool/mail</filename> location
92 for user mailboxes that Shadow uses by default to the <filename
93 class="directory">/var/mail</filename> location used currently:</para>
94
95<screen><userinput remap="configure">sed -i -e 's@#ENCRYPT_METHOD DES@ENCRYPT_METHOD MD5@' \
96 -e 's@/var/spool/mail@/var/mail@' etc/login.defs</userinput></screen>
97
98 <note>
99 <para>If you chose to build Shadow with Cracklib support, run the following:</para>
100
101<screen role="nodump"><userinput>sed -i 's@DICTPATH.*@DICTPATH\t/lib/cracklib/pw_dict@' \
102 etc/login.defs</userinput></screen>
103 </note>
104
105 <para>Prepare Shadow for compilation:</para>
106
107<!-- Keeping this in case we revert to an older version
108<screen><userinput remap="configure">./configure -libdir=/lib -sysconfdir=/etc -enable-shared \
109 -without-selinux</userinput></screen>
110-->
111
112<screen><userinput remap="configure">./configure --sysconfdir=/etc</userinput></screen>
113
114 <!-- <variablelist>
115 <title>The meaning of the configure options:</title>
116
117 <varlistentry>
118 <term><parameter>-without-selinux</parameter></term>
119 <listitem>
120 <para>Support for selinux is enabled by default, but selinux is not
121 built in a base LFS system. The <command>configure</command> script
122 will fail if this option is not used.</para>
123 </listitem>
124 </varlistentry>
125
126 </variablelist> -->
127
128 <para>Compile the package:</para>
129
130<screen><userinput remap="make">make</userinput></screen>
131
132 <para>This package does not come with a test suite.</para>
133
134 <para>Install the package:</para>
135
136<screen><userinput remap="install">make install</userinput></screen>
137
138 <para>Move a misplaced program to its proper location:</para>
139
140<screen><userinput remap="install">mv -v /usr/bin/passwd /bin</userinput></screen>
141
142 <!-- <para>Move Shadow's libraries to more appropriate locations:</para>
143
144<screen><userinput remap="install">mv -v /lib/libshadow.*a /usr/lib
145rm -v /lib/libshadow.so
146ln -sfv ../../lib/libshadow.so.0 /usr/lib/libshadow.so</userinput></screen> -->
147
148 </sect2>
149
150 <sect2 id="conf-shadow" role="configuration">
151 <title>Configuring Shadow</title>
152
153 <indexterm zone="conf-shadow">
154 <primary sortas="a-Shadow">Shadow</primary>
155 <secondary>configuring</secondary>
156 </indexterm>
157
158 <para>This package contains utilities to add, modify, and delete users and
159 groups; set and change their passwords; and perform other administrative
160 tasks. For a full explanation of what <emphasis>password shadowing</emphasis>
161 means, see the <filename>doc/HOWTO</filename> file within the unpacked
162 source tree. If using Shadow support, keep in mind that programs which need
163 to verify passwords (display managers, FTP programs, pop3 daemons, etc.)
164 must be Shadow-compliant. That is, they need to be able to work with
165 shadowed passwords.</para>
166
167 <para>To enable shadowed passwords, run the following command:</para>
168
169<screen><userinput>pwconv</userinput></screen>
170
171 <para>To enable shadowed group passwords, run:</para>
172
173<screen><userinput>grpconv</userinput></screen>
174
175 <para>Shadow's stock configuration for the <command>useradd</command>
176 utility has a few caveats that need some explanation. First, the default
177 action for the <command>useradd</command> utility is to create the user and
178 a group of the same name as the user. By default the user ID (UID) and
179 group ID (GID) numbers will begin with 1000. This means if you don't pass
180 parameters to <command>useradd</command>, each user will be a member of a
181 unique group on the system. If this behaviour is undesireable, you'll need
182 to pass the <parameter>-g</parameter> parameter to
183 <command>useradd</command>. The default parameters are stored in the
184 <filename>/etc/default/useradd</filename> file. You may need to modify two
185 parameters in this file to suit your particular needs.</para>
186
187 <variablelist>
188 <title><filename>/etc/default/useradd</filename> Parameter Explanations</title>
189
190 <varlistentry>
191 <term><parameter>GROUP=1000</parameter></term>
192 <listitem>
193 <para>This parameter sets the beginning of the group numbers used in
194 the /etc/group file. You can modify it to anything you desire. Note
195 that <command>useradd</command> will never reuse a UID or GID. If the
196 number identified in this parameter is used, it will use the next
197 available number after this. Note also that if you don't have a group
198 1000 on your system the first time you use <command>useradd</command>
199 without the <parameter>-g</parameter> parameter, you'll get a message
200 displayed on the terminal that says:
201 <computeroutput>useradd: unknown GID 1000</computeroutput>. You may
202 disregard this message and group number 1000 will be used.</para>
203 </listitem>
204 </varlistentry>
205 <varlistentry>
206 <term><parameter>CREATE_MAIL_SPOOL=yes</parameter></term>
207 <listitem>
208 <para>This parameter causes <command>useradd</command> to create a
209 mailbox file for the newly created user. <command>useradd</command>
210 will make the group ownership of this file to the
211 <systemitem class="groupname">mail</systemitem> group with 0660
212 permissions. If you would prefer that these mailbox files are not
213 created by <command>useradd</command>, issue the following
214 command:</para>
215
216<screen><userinput>sed -i 's/yes/no/' /etc/default/useradd</userinput></screen>
217 </listitem>
218 </varlistentry>
219
220 </variablelist>
221
222
223 </sect2>
224
225 <sect2 role="configuration">
226 <title>Setting the root password</title>
227
228 <para>Choose a password for user <emphasis>root</emphasis> and set it
229 by running:</para>
230
231<screen role="nodump"><userinput>passwd root</userinput></screen>
232
233 </sect2>
234
235 <sect2 id="contents-shadow" role="content">
236 <title>Contents of Shadow</title>
237
238 <segmentedlist>
239 <segtitle>Installed programs</segtitle>
240
241 <seglistitem>
242 <seg>chage, chfn, chgpasswd, chpasswd, chsh, expiry, faillog, gpasswd,
243 groupadd, groupdel, groupmems, groupmod, grpck, grpconv, grpunconv,
244 lastlog, login, logoutd, newgrp, newusers, nologin, passwd, pwck,
245 pwconv, pwunconv, sg (link to newgrp), su, useradd, userdel, usermod,
246 vigr (link to vipw), and vipw</seg>
247 </seglistitem>
248 </segmentedlist>
249
250 <variablelist>
251 <bridgehead renderas="sect3">Short Descriptions</bridgehead>
252 <?dbfo list-presentation="list"?>
253 <?dbhtml list-presentation="table"?>
254
255 <varlistentry id="chage">
256 <term><command>chage</command></term>
257 <listitem>
258 <para>Used to change the maximum number of days between obligatory
259 password changes</para>
260 <indexterm zone="ch-system-shadow chage">
261 <primary sortas="b-chage">chage</primary>
262 </indexterm>
263 </listitem>
264 </varlistentry>
265
266 <varlistentry id="chfn">
267 <term><command>chfn</command></term>
268 <listitem>
269 <para>Used to change a user's full name and other information</para>
270 <indexterm zone="ch-system-shadow chfn">
271 <primary sortas="b-chfn">chfn</primary>
272 </indexterm>
273 </listitem>
274 </varlistentry>
275
276 <varlistentry id="chgpasswd">
277 <term><command>chgpasswd</command></term>
278 <listitem>
279 <para>Used to update group passwords in batch mode</para>
280 <indexterm zone="ch-system-shadow chgpasswd">
281 <primary sortas="b-chgpasswd">chgpasswd</primary>
282 </indexterm>
283 </listitem>
284 </varlistentry>
285
286 <varlistentry id="chpasswd">
287 <term><command>chpasswd</command></term>
288 <listitem>
289 <para>Used to update user passwords in batch mode</para>
290 <indexterm zone="ch-system-shadow chpasswd">
291 <primary sortas="b-chpasswd">chpasswd</primary>
292 </indexterm>
293 </listitem>
294 </varlistentry>
295
296 <varlistentry id="chsh">
297 <term><command>chsh</command></term>
298 <listitem>
299 <para>Used to change a user's default login shell</para>
300 <indexterm zone="ch-system-shadow chsh">
301 <primary sortas="b-chsh">chsh</primary>
302 </indexterm>
303 </listitem>
304 </varlistentry>
305
306 <varlistentry id="expiry">
307 <term><command>expiry</command></term>
308 <listitem>
309 <para>Checks and enforces the current password expiration policy</para>
310 <indexterm zone="ch-system-shadow expiry">
311 <primary sortas="b-expiry">expiry</primary>
312 </indexterm>
313 </listitem>
314 </varlistentry>
315
316 <varlistentry id="faillog">
317 <term><command>faillog</command></term>
318 <listitem>
319 <para>Is used to examine the log of login failures, to set a maximum
320 number of failures before an account is blocked, or to reset the
321 failure count</para>
322 <indexterm zone="ch-system-shadow faillog">
323 <primary sortas="b-faillog">faillog</primary>
324 </indexterm>
325 </listitem>
326 </varlistentry>
327
328 <varlistentry id="gpasswd">
329 <term><command>gpasswd</command></term>
330 <listitem>
331 <para>Is used to add and delete members and administrators to
332 groups</para>
333 <indexterm zone="ch-system-shadow gpasswd">
334 <primary sortas="b-gpasswd">gpasswd</primary>
335 </indexterm>
336 </listitem>
337 </varlistentry>
338
339 <varlistentry id="groupadd">
340 <term><command>groupadd</command></term>
341 <listitem>
342 <para>Creates a group with the given name</para>
343 <indexterm zone="ch-system-shadow groupadd">
344 <primary sortas="b-groupadd">groupadd</primary>
345 </indexterm>
346 </listitem>
347 </varlistentry>
348
349 <varlistentry id="groupdel">
350 <term><command>groupdel</command></term>
351 <listitem>
352 <para>Deletes the group with the given name</para>
353 <indexterm zone="ch-system-shadow groupdel">
354 <primary sortas="b-groupdel">groupdel</primary>
355 </indexterm>
356 </listitem>
357 </varlistentry>
358
359 <varlistentry id="groupmems">
360 <term><command>groupmems</command></term>
361 <listitem>
362 <para>Allows a user to administer his/her own group membership list
363 without the requirement of super user privileges.</para>
364 <indexterm zone="ch-system-shadow groupmems">
365 <primary sortas="b-groupmems">groupmems</primary>
366 </indexterm>
367 </listitem>
368 </varlistentry>
369
370 <varlistentry id="groupmod">
371 <term><command>groupmod</command></term>
372 <listitem>
373 <para>Is used to modify the given group's name or GID</para>
374 <indexterm zone="ch-system-shadow groupmod">
375 <primary sortas="b-groupmod">groupmod</primary>
376 </indexterm>
377 </listitem>
378 </varlistentry>
379
380 <varlistentry id="grpck">
381 <term><command>grpck</command></term>
382 <listitem>
383 <para>Verifies the integrity of the group files
384 <filename>/etc/group</filename> and
385 <filename>/etc/gshadow</filename></para>
386 <indexterm zone="ch-system-shadow grpck">
387 <primary sortas="b-grpck">grpck</primary>
388 </indexterm>
389 </listitem>
390 </varlistentry>
391
392 <varlistentry id="grpconv">
393 <term><command>grpconv</command></term>
394 <listitem>
395 <para>Creates or updates the shadow group file from the normal
396 group file</para>
397 <indexterm zone="ch-system-shadow grpconv">
398 <primary sortas="b-grpconv">grpconv</primary>
399 </indexterm>
400 </listitem>
401 </varlistentry>
402
403 <varlistentry id="grpunconv">
404 <term><command>grpunconv</command></term>
405 <listitem>
406 <para>Updates <filename>/etc/group</filename> from
407 <filename>/etc/gshadow</filename> and then deletes the latter</para>
408 <indexterm zone="ch-system-shadow grpunconv">
409 <primary sortas="b-grpunconv">grpunconv</primary>
410 </indexterm>
411 </listitem>
412 </varlistentry>
413
414 <varlistentry id="lastlog">
415 <term><command>lastlog</command></term>
416 <listitem>
417 <para>Reports the most recent login of all users or of a
418 given user</para>
419 <indexterm zone="ch-system-shadow lastlog">
420 <primary sortas="b-lastlog">lastlog</primary>
421 </indexterm>
422 </listitem>
423 </varlistentry>
424
425 <varlistentry id="login">
426 <term><command>login</command></term>
427 <listitem>
428 <para>Is used by the system to let users sign on</para>
429 <indexterm zone="ch-system-shadow login">
430 <primary sortas="b-login">login</primary>
431 </indexterm>
432 </listitem>
433 </varlistentry>
434
435 <varlistentry id="logoutd">
436 <term><command>logoutd</command></term>
437 <listitem>
438 <para>Is a daemon used to enforce restrictions on log-on time
439 and ports</para>
440 <indexterm zone="ch-system-shadow logoutd">
441 <primary sortas="b-logoutd">logoutd</primary>
442 </indexterm>
443 </listitem>
444 </varlistentry>
445
446 <varlistentry id="newgrp">
447 <term><command>newgrp</command></term>
448 <listitem>
449 <para>Is used to change the current GID during a login session</para>
450 <indexterm zone="ch-system-shadow newgrp">
451 <primary sortas="b-newgrp">newgrp</primary>
452 </indexterm>
453 </listitem>
454 </varlistentry>
455
456 <varlistentry id="newusers">
457 <term><command>newusers</command></term>
458 <listitem>
459 <para>Is used to create or update an entire series of user
460 accounts</para>
461 <indexterm zone="ch-system-shadow newusers">
462 <primary sortas="b-newusers">newusers</primary>
463 </indexterm>
464 </listitem>
465 </varlistentry>
466
467 <varlistentry id="nologin">
468 <term><command>nologin</command></term>
469 <listitem>
470 <para>Displays a message that an account is not available. Designed
471 to be used as the default shell for accounts that have been
472 disabled</para>
473 <indexterm zone="ch-system-shadow nologin">
474 <primary sortas="b-nologin">nologin</primary>
475 </indexterm>
476 </listitem>
477 </varlistentry>
478
479 <varlistentry id="passwd">
480 <term><command>passwd</command></term>
481 <listitem>
482 <para>Is used to change the password for a user or group account</para>
483 <indexterm zone="ch-system-shadow passwd">
484 <primary sortas="b-passwd">passwd</primary>
485 </indexterm>
486 </listitem>
487 </varlistentry>
488
489 <varlistentry id="pwck">
490 <term><command>pwck</command></term>
491 <listitem>
492 <para>Verifies the integrity of the password files
493 <filename>/etc/passwd</filename> and
494 <filename>/etc/shadow</filename></para>
495 <indexterm zone="ch-system-shadow pwck">
496 <primary sortas="b-pwck">pwck</primary>
497 </indexterm>
498 </listitem>
499 </varlistentry>
500
501 <varlistentry id="pwconv">
502 <term><command>pwconv</command></term>
503 <listitem>
504 <para>Creates or updates the shadow password file from the normal
505 password file</para>
506 <indexterm zone="ch-system-shadow pwconv">
507 <primary sortas="b-pwconv">pwconv</primary>
508 </indexterm>
509 </listitem>
510 </varlistentry>
511
512 <varlistentry id="pwunconv">
513 <term><command>pwunconv</command></term>
514 <listitem>
515 <para>Updates <filename>/etc/passwd</filename> from
516 <filename>/etc/shadow</filename> and then deletes the latter</para>
517 <indexterm zone="ch-system-shadow pwunconv">
518 <primary sortas="b-pwunconv">pwunconv</primary>
519 </indexterm>
520 </listitem>
521 </varlistentry>
522
523 <varlistentry id="sg">
524 <term><command>sg</command></term>
525 <listitem>
526 <para>Executes a given command while the user's GID
527 is set to that of the given group</para>
528 <indexterm zone="ch-system-shadow sg">
529 <primary sortas="b-sg">sg</primary>
530 </indexterm>
531 </listitem>
532 </varlistentry>
533
534 <varlistentry id="su">
535 <term><command>su</command></term>
536 <listitem>
537 <para>Runs a shell with substitute user and group IDs</para>
538 <indexterm zone="ch-system-shadow su">
539 <primary sortas="b-su">su</primary>
540 </indexterm>
541 </listitem>
542 </varlistentry>
543
544 <varlistentry id="useradd">
545 <term><command>useradd</command></term>
546 <listitem>
547 <para>Creates a new user with the given name, or updates the default
548 new-user information</para>
549 <indexterm zone="ch-system-shadow useradd">
550 <primary sortas="b-useradd">useradd</primary>
551 </indexterm>
552 </listitem>
553 </varlistentry>
554
555 <varlistentry id="userdel">
556 <term><command>userdel</command></term>
557 <listitem>
558 <para>Deletes the given user account</para>
559 <indexterm zone="ch-system-shadow userdel">
560 <primary sortas="b-userdel">userdel</primary>
561 </indexterm>
562 </listitem>
563 </varlistentry>
564
565 <varlistentry id="usermod">
566 <term><command>usermod</command></term>
567 <listitem>
568 <para>Is used to modify the given user's login name, User
569 Identification (UID), shell, initial group, home directory, etc.</para>
570 <indexterm zone="ch-system-shadow usermod">
571 <primary sortas="b-usermod">usermod</primary>
572 </indexterm>
573 </listitem>
574 </varlistentry>
575
576 <varlistentry id="vigr">
577 <term><command>vigr</command></term>
578 <listitem>
579 <para>Edits the <filename>/etc/group</filename> or
580 <filename>/etc/gshadow</filename> files</para>
581 <indexterm zone="ch-system-shadow vigr">
582 <primary sortas="b-vigr">vigr</primary>
583 </indexterm>
584 </listitem>
585 </varlistentry>
586
587 <varlistentry id="vipw">
588 <term><command>vipw</command></term>
589 <listitem>
590 <para>Edits the <filename>/etc/passwd</filename> or
591 <filename>/etc/shadow</filename> files</para>
592 <indexterm zone="ch-system-shadow vipw">
593 <primary sortas="b-vipw">vipw</primary>
594 </indexterm>
595 </listitem>
596 </varlistentry>
597
598 </variablelist>
599
600 </sect2>
601
602</sect1>
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