source: clfs-sysroot/BOOK/final-system/common/shadow.xml@ 6c98d4f

Last change on this file since 6c98d4f was 5590e0d, checked in by Joe Ciccone <jciccone@…>, 18 years ago

Brought the clfs-2.0 branch up to trunk.
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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 %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="&blfs-root;view/svn/postlfs/cracklib.html"/>
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">Create a config.cache containing information about a test that
37 cannot be run when cross-compiling:</para>
38
39<screen os="c"><userinput>echo "ac_cv_func_setpgrp_void=yes" &gt; config.cache</userinput></screen>
40
41 <para os="d">Prepare Shadow for compilation:</para>
42
43<screen os="e"><userinput>./configure --libdir=/lib --sysconfdir=/etc --enable-shared \
44 --without-libpam --without-audit --without-selinux \
45 --host=${LFS_TARGET} --cache-file=config.cache</userinput></screen>
46
47<para os="f">The meaning of the configure options:</para>
48
49 <variablelist os="g">
50 <varlistentry>
51 <term><parameter>--without-libpam</parameter></term>
52 <listitem><para>Support for Linux-PAM is enabled by default in Shadow,
53 however PAM is not installed on a base CLFS system, so this switch
54 disables PAM support in Shadow. For instructions to install PAM and
55 link Shadow to it, you can look at
56 <ulink url="&blfs-root;view/svn/postlfs/shadow.html"/>.</para></listitem>
57 </varlistentry>
58 <varlistentry>
59 <term><parameter>--without-audit</parameter></term>
60 <listitem><para>Support for auditing is enabled by default, but a
61 library that it needs is not installed in a base CLFS system. This
62 switch disables auditing support.</para></listitem>
63 </varlistentry>
64 <varlistentry>
65 <term><parameter>--without-selinux</parameter></term>
66 <listitem><para>Support for selinux is enabled by default, but selinux
67 is not built in a base CLFS system and configure will fail without this
68 switch.</para></listitem>
69 </varlistentry>
70 </variablelist>
71
72 <para os="h">Disable the installation of the <command>groups</command>
73 program and its man pages, as Coreutils provides a better version:</para>
74
75<screen os="i"><userinput>cp src/Makefile{,.orig}
76sed 's/groups$(EXEEXT) //' src/Makefile.orig &gt; src/Makefile
77cp man/Makefile{,.orig}
78sed '/groups/d' man/Makefile.orig &gt; man/Makefile</userinput></screen>
79
80 <para os="j">Compile the package:</para>
81
82<screen os="k"><userinput>make</userinput></screen>
83
84 <para os="l">Install the package:</para>
85
86<screen os="m"><userinput>make DESTDIR=${LFS} install</userinput></screen>
87
88 <para id="shadow-login_defs" os="r">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 zone="shadow-login_defs" os="s">
99 <primary sortas="e-/etc/login.defs">/etc/login.defs</primary>
100 </indexterm>
101
102<screen os="t"><userinput>cp ${LFS}/etc/login.defs login.defs.orig
103sed -e's@#MD5_CRYPT_ENAB.no@MD5_CRYPT_ENAB yes@' \
104 -e 's@/var/spool/mail@/var/mail@' \
105 login.defs.orig &gt; ${LFS}/etc/login.defs</userinput></screen>
106
107 <note os="u">
108 <para>If you built Shadow with Cracklib support, execute
109 this <command>sed</command> to correct the path to the Cracklib
110 dictionary:</para>
111
112<screen><userinput>cp {LFS}/etc/login.defs login.defs.orig
113sed 's@DICTPATH.*@DICTPATH\t/lib/cracklib/pw_dict@' login.defs.orig &gt; ${LFS}/etc/login.defs</userinput></screen>
114 </note>
115
116 <para os="v">Move a misplaced program to its proper location:</para>
117
118<screen os="w"><userinput>mv -v ${LFS}/usr/bin/passwd ${LFS}/bin</userinput></screen>
119
120 <para os="x">Move Shadow's dynamic libraries to a more appropriate
121 location:</para>
122
123<screen os="y"><userinput>mv -v ${LFS}/lib/libshadow.*a ${LFS}/usr/lib
124rm -v ${LFS}/lib/libshadow.so
125ln -svf ../../lib/libshadow.so.0 ${LFS}/usr/lib/libshadow.so</userinput></screen>
126
127 </sect2>
128
129 <sect2 id="conf-shadow" role="configuration">
130 <title>Configuring Shadow</title>
131
132 <indexterm zone="conf-shadow">
133 <primary sortas="a-Shadow">Shadow</primary>
134 <secondary>configuring</secondary>
135 </indexterm>
136
137 <para>This package contains utilities to add, modify, and delete users and
138 groups; set and change their passwords; and perform other administrative
139 tasks. For a full explanation of what <emphasis>password shadowing</emphasis>
140 means, see the <filename>doc/HOWTO</filename> file within the unpacked source
141 tree. If using Shadow support, keep in mind that programs which need to
142 verify passwords (display managers, FTP programs, pop3 daemons, etc.) must
143 be Shadow-compliant. That is, they need to be able to work with shadowed
144 passwords.</para>
145
146 <para>To enable shadowed passwords, run the following command:</para>
147
148<screen><userinput>pwconv</userinput></screen>
149
150 <para>To enable shadowed group passwords, run:</para>
151
152<screen role="nodump"><userinput>grpconv</userinput></screen>
153
154 <para>To view or change the default settings for new user accounts that
155 you create, you can edit <filename>/etc/default/useradd</filename>. See
156 <command>man useradd</command> or
157 <ulink url="&blfs-root;view/svn/postlfs/skel.html"/> for more
158 information.</para>
159
160 </sect2>
161
162 <sect2 id="root-password" role="configuration">
163 <title>Setting the root password</title>
164
165 <para>Choose a password for user <systemitem
166 class="username">root</systemitem> and set it by running:</para>
167
168<screen role="nodump"><userinput>passwd root</userinput></screen>
169
170 </sect2>
171
172 <sect2 id="contents-shadow" role="content">
173 <title>Contents of Shadow</title>
174
175 <segmentedlist>
176 <segtitle>Installed programs</segtitle>
177 <segtitle>Installed libraries</segtitle>
178
179 <seglistitem>
180 <seg>chage, chfn, chpasswd, chgpasswd, chsh, expiry, faillog, gpasswd,
181 groupadd, groupdel, groupmod, grpck, grpconv, grpunconv, lastlog,
182 login, logoutd, newgrp, newusers, nologin, passwd, pwck, pwconv,
183 pwunconv, sg (link to newgrp), useradd, userdel, usermod,
184 vigr (link to vipw), and vipw</seg>
185 <seg>libshadow.[a,so]</seg>
186 </seglistitem>
187 </segmentedlist>
188
189 <variablelist>
190 <bridgehead renderas="sect3">Short Descriptions</bridgehead>
191 <?dbfo list-presentation="list"?>
192 <?dbhtml list-presentation="table"?>
193
194 <varlistentry id="chage">
195 <term><command>chage</command></term>
196 <listitem>
197 <para>Used to change the maximum number of days between obligatory
198 password changes</para>
199 <indexterm zone="ch-system-shadow chage">
200 <primary sortas="b-chage">chage</primary>
201 </indexterm>
202 </listitem>
203 </varlistentry>
204
205 <varlistentry id="chfn">
206 <term><command>chfn</command></term>
207 <listitem>
208 <para>Used to change a user's full name and other information</para>
209 <indexterm zone="ch-system-shadow chfn">
210 <primary sortas="b-chfn">chfn</primary>
211 </indexterm>
212 </listitem>
213 </varlistentry>
214
215 <varlistentry id="chgpasswd">
216 <term><command>chgpasswd</command></term>
217 <listitem>
218 <para>Used to update group passwords in batch mode</para>
219 <indexterm zone="ch-system-shadow chgpasswd">
220 <primary sortas="b-chgpasswd">chgpasswd</primary>
221 </indexterm>
222 </listitem>
223 </varlistentry>
224
225 <varlistentry id="chpasswd">
226 <term><command>chpasswd</command></term>
227 <listitem>
228 <para>Used to update the passwords of an entire series of user
229 accounts</para>
230 <indexterm zone="ch-system-shadow chpasswd">
231 <primary sortas="b-chpasswd">chpasswd</primary>
232 </indexterm>
233 </listitem>
234 </varlistentry>
235
236 <varlistentry id="chsh">
237 <term><command>chsh</command></term>
238 <listitem>
239 <para>Used to change a user's default login shell</para>
240 <indexterm zone="ch-system-shadow chsh">
241 <primary sortas="b-chsh">chsh</primary>
242 </indexterm>
243 </listitem>
244 </varlistentry>
245
246 <varlistentry id="expiry">
247 <term><command>expiry</command></term>
248 <listitem>
249 <para>Checks and enforces the current password expiration policy</para>
250 <indexterm zone="ch-system-shadow expiry">
251 <primary sortas="b-expiry">expiry</primary>
252 </indexterm>
253 </listitem>
254 </varlistentry>
255
256 <varlistentry id="faillog">
257 <term><command>faillog</command></term>
258 <listitem>
259 <para>Is used to examine the log of login failures, to set a maximum
260 number of failures before an account is blocked, or to reset the
261 failure count</para>
262 <indexterm zone="ch-system-shadow faillog">
263 <primary sortas="b-faillog">faillog</primary>
264 </indexterm>
265 </listitem>
266 </varlistentry>
267
268 <varlistentry id="gpasswd">
269 <term><command>gpasswd</command></term>
270 <listitem>
271 <para>Is used to add and delete members and administrators to
272 groups</para>
273 <indexterm zone="ch-system-shadow gpasswd">
274 <primary sortas="b-gpasswd">gpasswd</primary>
275 </indexterm>
276 </listitem>
277 </varlistentry>
278
279 <varlistentry id="groupadd">
280 <term><command>groupadd</command></term>
281 <listitem>
282 <para>Creates a group with the given name</para>
283 <indexterm zone="ch-system-shadow groupadd">
284 <primary sortas="b-groupadd">groupadd</primary>
285 </indexterm>
286 </listitem>
287 </varlistentry>
288
289 <varlistentry id="groupdel">
290 <term><command>groupdel</command></term>
291 <listitem>
292 <para>Deletes the group with the given name</para>
293 <indexterm zone="ch-system-shadow groupdel">
294 <primary sortas="b-groupdel">groupdel</primary>
295 </indexterm>
296 </listitem>
297 </varlistentry>
298
299 <varlistentry id="groupmod">
300 <term><command>groupmod</command></term>
301 <listitem>
302 <para>Is used to modify the given group's name or GID</para>
303 <indexterm zone="ch-system-shadow groupmod">
304 <primary sortas="b-groupmod">groupmod</primary>
305 </indexterm>
306 </listitem>
307 </varlistentry>
308
309 <varlistentry id="grpck">
310 <term><command>grpck</command></term>
311 <listitem>
312 <para>Verifies the integrity of the group files
313 <filename>/etc/group</filename> and
314 <filename>/etc/gshadow</filename></para>
315 <indexterm zone="ch-system-shadow grpck">
316 <primary sortas="b-grpck">grpck</primary>
317 </indexterm>
318 </listitem>
319 </varlistentry>
320
321 <varlistentry id="grpconv">
322 <term><command>grpconv</command></term>
323 <listitem>
324 <para>Creates or updates the shadow group file from the normal
325 group file</para>
326 <indexterm zone="ch-system-shadow grpconv">
327 <primary sortas="b-grpconv">grpconv</primary>
328 </indexterm>
329 </listitem>
330 </varlistentry>
331
332 <varlistentry id="grpunconv">
333 <term><command>grpunconv</command></term>
334 <listitem>
335 <para>Updates <filename>/etc/group</filename> from
336 <filename>/etc/gshadow</filename> and then deletes the latter</para>
337 <indexterm zone="ch-system-shadow grpunconv">
338 <primary sortas="b-grpunconv">grpunconv</primary>
339 </indexterm>
340 </listitem>
341 </varlistentry>
342
343 <varlistentry id="lastlog">
344 <term><command>lastlog</command></term>
345 <listitem>
346 <para>Reports the most recent login of all users or of a
347 given user</para>
348 <indexterm zone="ch-system-shadow lastlog">
349 <primary sortas="b-lastlog">lastlog</primary>
350 </indexterm>
351 </listitem>
352 </varlistentry>
353
354 <varlistentry id="login">
355 <term><command>login</command></term>
356 <listitem>
357 <para>Is used by the system to let users sign on</para>
358 <indexterm zone="ch-system-shadow login">
359 <primary sortas="b-login">login</primary>
360 </indexterm>
361 </listitem>
362 </varlistentry>
363
364 <varlistentry id="logoutd">
365 <term><command>logoutd</command></term>
366 <listitem>
367 <para>Is a daemon used to enforce restrictions on log-on time
368 and ports</para>
369 <indexterm zone="ch-system-shadow logoutd">
370 <primary sortas="b-logoutd">logoutd</primary>
371 </indexterm>
372 </listitem>
373 </varlistentry>
374
375 <varlistentry id="newgrp">
376 <term><command>newgrp</command></term>
377 <listitem>
378 <para>Is used to change the current GID during a login session</para>
379 <indexterm zone="ch-system-shadow newgrp">
380 <primary sortas="b-newgrp">newgrp</primary>
381 </indexterm>
382 </listitem>
383 </varlistentry>
384
385 <varlistentry id="newusers">
386 <term><command>newusers</command></term>
387 <listitem>
388 <para>Is used to create or update an entire series of user
389 accounts</para>
390 <indexterm zone="ch-system-shadow newusers">
391 <primary sortas="b-newusers">newusers</primary>
392 </indexterm>
393 </listitem>
394 </varlistentry>
395
396 <varlistentry id="nologin">
397 <term><command>nologin</command></term>
398 <listitem>
399 <para>Displays a message that an account is not available. Designed
400 to be used as the default shell for accounts that have been
401 disabled</para>
402 <indexterm zone="ch-system-shadow nologin">
403 <primary sortas="b-nologin">nologin</primary>
404 </indexterm>
405 </listitem>
406 </varlistentry>
407
408 <varlistentry id="passwd">
409 <term><command>passwd</command></term>
410 <listitem>
411 <para>Is used to change the password for a user or group account</para>
412 <indexterm zone="ch-system-shadow passwd">
413 <primary sortas="b-passwd">passwd</primary>
414 </indexterm>
415 </listitem>
416 </varlistentry>
417
418 <varlistentry id="pwck">
419 <term><command>pwck</command></term>
420 <listitem>
421 <para>Verifies the integrity of the password files
422 <filename>/etc/passwd</filename> and
423 <filename>/etc/shadow</filename></para>
424 <indexterm zone="ch-system-shadow pwck">
425 <primary sortas="b-pwck">pwck</primary>
426 </indexterm>
427 </listitem>
428 </varlistentry>
429
430 <varlistentry id="pwconv">
431 <term><command>pwconv</command></term>
432 <listitem>
433 <para>Creates or updates the shadow password file from the normal
434 password file</para>
435 <indexterm zone="ch-system-shadow pwconv">
436 <primary sortas="b-pwconv">pwconv</primary>
437 </indexterm>
438 </listitem>
439 </varlistentry>
440
441 <varlistentry id="pwunconv">
442 <term><command>pwunconv</command></term>
443 <listitem>
444 <para>Updates <filename>/etc/passwd</filename> from
445 <filename>/etc/shadow</filename> and then deletes the latter</para>
446 <indexterm zone="ch-system-shadow pwunconv">
447 <primary sortas="b-pwunconv">pwunconv</primary>
448 </indexterm>
449 </listitem>
450 </varlistentry>
451
452 <varlistentry id="sg">
453 <term><command>sg</command></term>
454 <listitem>
455 <para>Executes a given command while the user's GID
456 is set to that of the given group</para>
457 <indexterm zone="ch-system-shadow sg">
458 <primary sortas="b-sg">sg</primary>
459 </indexterm>
460 </listitem>
461 </varlistentry>
462
463 <varlistentry id="su">
464 <term><command>su</command></term>
465 <listitem>
466 <para>Runs a shell with substitute user and group IDs</para>
467 <indexterm zone="ch-system-shadow su">
468 <primary sortas="b-su">su</primary>
469 </indexterm>
470 </listitem>
471 </varlistentry>
472
473 <varlistentry id="useradd">
474 <term><command>useradd</command></term>
475 <listitem>
476 <para>Creates a new user with the given name, or updates the default
477 new-user information</para>
478 <indexterm zone="ch-system-shadow useradd">
479 <primary sortas="b-useradd">useradd</primary>
480 </indexterm>
481 </listitem>
482 </varlistentry>
483
484 <varlistentry id="userdel">
485 <term><command>userdel</command></term>
486 <listitem>
487 <para>Deletes the given user account</para>
488 <indexterm zone="ch-system-shadow userdel">
489 <primary sortas="b-userdel">userdel</primary>
490 </indexterm>
491 </listitem>
492 </varlistentry>
493
494 <varlistentry id="usermod">
495 <term><command>usermod</command></term>
496 <listitem>
497 <para>Is used to modify the given user's login name, User
498 Identification (UID), shell, initial group, home directory, etc.</para>
499 <indexterm zone="ch-system-shadow usermod">
500 <primary sortas="b-usermod">usermod</primary>
501 </indexterm>
502 </listitem>
503 </varlistentry>
504
505 <varlistentry id="vigr">
506 <term><command>vigr</command></term>
507 <listitem>
508 <para>Edits the <filename>/etc/group</filename> or
509 <filename>/etc/gshadow</filename> files</para>
510 <indexterm zone="ch-system-shadow vigr">
511 <primary sortas="b-vigr">vigr</primary>
512 </indexterm>
513 </listitem>
514 </varlistentry>
515
516 <varlistentry id="vipw">
517 <term><command>vipw</command></term>
518 <listitem>
519 <para>Edits the <filename>/etc/passwd</filename> or
520 <filename>/etc/shadow</filename> files</para>
521 <indexterm zone="ch-system-shadow vipw">
522 <primary sortas="b-vipw">vipw</primary>
523 </indexterm>
524 </listitem>
525 </varlistentry>
526
527 <varlistentry id="libshadow">
528 <term><filename class="libraryfile">libshadow</filename></term>
529 <listitem>
530 <para>Contains functions used by most programs in this package</para>
531 <indexterm zone="ch-system-shadow libshadow">
532 <primary sortas="c-libshadow">libshadow</primary>
533 </indexterm>
534 </listitem>
535 </varlistentry>
536
537 </variablelist>
538
539 </sect2>
540
541</sect1>
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