source: clfs-sysroot/BOOK/final-system/common/shadow.xml@ 7126617

Last change on this file since 7126617 was 02095ae, checked in by Jim Gifford <clfs@…>, 19 years ago

r3633@server (orig r1649): jciccone | 2006-05-25 16:48:42 -0700
Added the Initial clfs-2.0 branch using sysroot builds.
  • Property mode set to 100644
File size: 19.0 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 %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 --enable-shared \
44 --without-libpam --without-audit --without-selinux \
45 --host=${LFS_TARGET} --cache-file=config.cache</userinput></screen>
46
47<para os="f">The meaning of the configure options:</para>
48
49 <variablelist os="g">
50 <varlistentry>
51 <term><parameter>--without-libpam</parameter></term>
52 <listitem><para>Support for Linux-PAM is enabled by default in Shadow,
53 however PAM is not installed on a base LFS system, so this switch
54 disables PAM support in Shadow. For instructions to install PAM and
55 link Shadow to it, you can look at
56 <ulink url="&blfs-root;view/svn/postlfs/shadow.html"/>.</para></listitem>
57 </varlistentry>
58 <varlistentry>
59 <term><parameter>--without-audit</parameter></term>
60 <listitem><para>Support for auditing is enabled by default, but a
61 a library that it needs is not installed in a base LFS system. This
62 switch disables auditing support.</para></listitem>
63 </varlistentry>
64 <varlistentry>
65 <term><parameter>--without-selinux</parameter></term>
66 <listitem><para>Support for selinux is enabled by default, but selinux
67 is not built in a base LFS system and configure will fail without this
68 switch.</para></listitem>
69 </varlistentry>
70 </variablelist>
71
72 <para os="h">Disable the installation of the <command>groups</command>
73 program and its man pages, as Coreutils provides a better version:</para>
74
75<screen os="i"><userinput>sed -i 's/groups$(EXEEXT) //' src/Makefile
76sed -i '/groups/d' man/Makefile</userinput></screen>
77
78 <para os="j">Compile the package:</para>
79
80<screen os="k"><userinput>make</userinput></screen>
81
82 <para os="l">Install the package:</para>
83
84<screen os="m"><userinput>make DESTDIR=${LFS} install</userinput></screen>
85
86 <para id="shadow-limits-login_access" os="n">Shadow uses two files to configure
87 authentication settings for the system. Install these two configuration
88 files:</para>
89
90 <indexterm zone="shadow-limits-login_access" os="o">
91 <primary sortas="e-/etc/limits">/etc/limits</primary>
92 </indexterm>
93
94 <indexterm zone="shadow-limits-login_access" os="p">
95 <primary sortas="e-/etc/login.access">/etc/login.access</primary>
96 </indexterm>
97
98<screen os="q"><userinput>cp -v etc/{limits,login.access} ${LFS}/etc</userinput></screen>
99
100 <para id="shadow-login_defs" os="r">Instead of using the default
101 <emphasis>crypt</emphasis> method, use the more secure
102 <emphasis>MD5</emphasis> method of password encryption, which also allows
103 passwords longer than 8 characters. It is also necessary to change the
104 obsolete <filename class="directory">/var/spool/mail</filename> location
105 for user mailboxes that Shadow uses by default to the <filename
106 class="directory">/var/mail</filename> location used currently. Both of
107 these can be accomplished by changing the relevant configuration file
108 while copying it to its destination:</para>
109
110 <indexterm zone="shadow-login_defs" os="s">
111 <primary sortas="e-/etc/login.defs">/etc/login.defs</primary>
112 </indexterm>
113
114<screen os="t"><userinput>sed -e's@#MD5_CRYPT_ENAB.no@MD5_CRYPT_ENAB yes@' \
115 -e 's@/var/spool/mail@/var/mail@' \
116 etc/login.defs &gt; ${LFS}/etc/login.defs</userinput></screen>
117
118 <note os="u">
119 <para>If you built Shadow with Cracklib support, execute
120 this <command>sed</command> to correct the path to the Cracklib
121 dictionary:</para>
122
123<screen><userinput>sed -i 's@DICTPATH.*@DICTPATH\t/lib/cracklib/pw_dict@' ${LFS}/etc/login.defs</userinput></screen>
124 </note>
125
126 <para os="v">Move a misplaced program to its proper location:</para>
127
128<screen os="w"><userinput>mv -v ${LFS}/usr/bin/passwd ${LFS}/bin</userinput></screen>
129
130 <para os="x">Move Shadow's dynamic libraries to a more appropriate
131 location:</para>
132
133<screen os="y"><userinput>mv -v ${LFS}/lib/libshadow.*a ${LFS}/usr/lib
134rm -v ${LFS}/lib/libshadow.so
135ln -svf ../../lib/libshadow.so.0 ${LFS}/usr/lib/libshadow.so</userinput></screen>
136
137 <para os="z">The <option>-D</option> option of the <command>useradd</command>
138 program requires the <filename class="directory">/etc/default</filename>
139 directory for it to work properly:</para>
140
141<screen os="za"><userinput>install -dv ${LFS}/etc/default</userinput></screen>
142
143 </sect2>
144
145 <sect2 id="conf-shadow" role="configuration">
146 <title>Configuring Shadow</title>
147
148 <indexterm zone="conf-shadow">
149 <primary sortas="a-Shadow">Shadow</primary>
150 <secondary>configuring</secondary>
151 </indexterm>
152
153 <para>This package contains utilities to add, modify, and delete users and
154 groups; set and change their passwords; and perform other administrative
155 tasks. For a full explanation of what <emphasis>password shadowing</emphasis>
156 means, see the <filename>doc/HOWTO</filename> file within the unpacked source
157 tree. If using Shadow support, keep in mind that programs which need to
158 verify passwords (display managers, FTP programs, pop3 daemons, etc.) must
159 be Shadow-compliant. That is, they need to be able to work with shadowed
160 passwords.</para>
161
162 <para>To enable shadowed passwords, run the following command:</para>
163
164<screen><userinput>pwconv</userinput></screen>
165
166 <para>To enable shadowed group passwords, run:</para>
167
168<screen role="nodump"><userinput>grpconv</userinput></screen>
169
170 <para>Under normal circumstances, passwords will not have been created
171 yet. However, if returning to this section later to enable shadowing,
172 reset any current user passwords with the <command>passwd</command>
173 command or any group passwords with the <command>gpasswd</command>
174 command.</para>
175
176 </sect2>
177
178 <sect2 id="root-password" role="configuration">
179 <title>Setting the root password</title>
180
181 <para>Choose a password for user <systemitem
182 class="username">root</systemitem> and set it by running:</para>
183
184<screen role="nodump"><userinput>passwd root</userinput></screen>
185
186 </sect2>
187
188 <sect2 id="contents-shadow" role="content">
189 <title>Contents of Shadow</title>
190
191 <segmentedlist>
192 <segtitle>Installed programs</segtitle>
193 <segtitle>Installed libraries</segtitle>
194
195 <seglistitem>
196 <seg>chage, chfn, chpasswd, chsh, expiry, faillog, gpasswd, groupadd,
197 groupdel, groupmod, grpck, grpconv, grpunconv, lastlog, login,
198 logoutd, newgrp, newusers, passwd, pwck, pwconv, pwunconv,
199 sg (link to newgrp), useradd, userdel, usermod, vigr (link to vipw),
200 and vipw</seg>
201 <seg>libshadow.[a,so]</seg>
202 </seglistitem>
203 </segmentedlist>
204
205 <variablelist>
206 <bridgehead renderas="sect3">Short Descriptions</bridgehead>
207 <?dbfo list-presentation="list"?>
208 <?dbhtml list-presentation="table"?>
209
210 <varlistentry id="chage">
211 <term><command>chage</command></term>
212 <listitem>
213 <para>Used to change the maximum number of days between obligatory
214 password changes</para>
215 <indexterm zone="ch-system-shadow chage">
216 <primary sortas="b-chage">chage</primary>
217 </indexterm>
218 </listitem>
219 </varlistentry>
220
221 <varlistentry id="chfn">
222 <term><command>chfn</command></term>
223 <listitem>
224 <para>Used to change a user's full name and other information</para>
225 <indexterm zone="ch-system-shadow chfn">
226 <primary sortas="b-chfn">chfn</primary>
227 </indexterm>
228 </listitem>
229 </varlistentry>
230
231 <varlistentry id="chpasswd">
232 <term><command>chpasswd</command></term>
233 <listitem>
234 <para>Used to update the passwords of an entire series of user
235 accounts</para>
236 <indexterm zone="ch-system-shadow chpasswd">
237 <primary sortas="b-chpasswd">chpasswd</primary>
238 </indexterm>
239 </listitem>
240 </varlistentry>
241
242 <varlistentry id="chsh">
243 <term><command>chsh</command></term>
244 <listitem>
245 <para>Used to change a user's default login shell</para>
246 <indexterm zone="ch-system-shadow chsh">
247 <primary sortas="b-chsh">chsh</primary>
248 </indexterm>
249 </listitem>
250 </varlistentry>
251
252 <varlistentry id="expiry">
253 <term><command>expiry</command></term>
254 <listitem>
255 <para>Checks and enforces the current password expiration policy</para>
256 <indexterm zone="ch-system-shadow expiry">
257 <primary sortas="b-expiry">expiry</primary>
258 </indexterm>
259 </listitem>
260 </varlistentry>
261
262 <varlistentry id="faillog">
263 <term><command>faillog</command></term>
264 <listitem>
265 <para>Is used to examine the log of login failures, to set a maximum
266 number of failures before an account is blocked, or to reset the
267 failure count</para>
268 <indexterm zone="ch-system-shadow faillog">
269 <primary sortas="b-faillog">faillog</primary>
270 </indexterm>
271 </listitem>
272 </varlistentry>
273
274 <varlistentry id="gpasswd">
275 <term><command>gpasswd</command></term>
276 <listitem>
277 <para>Is used to add and delete members and administrators to
278 groups</para>
279 <indexterm zone="ch-system-shadow gpasswd">
280 <primary sortas="b-gpasswd">gpasswd</primary>
281 </indexterm>
282 </listitem>
283 </varlistentry>
284
285 <varlistentry id="groupadd">
286 <term><command>groupadd</command></term>
287 <listitem>
288 <para>Creates a group with the given name</para>
289 <indexterm zone="ch-system-shadow groupadd">
290 <primary sortas="b-groupadd">groupadd</primary>
291 </indexterm>
292 </listitem>
293 </varlistentry>
294
295 <varlistentry id="groupdel">
296 <term><command>groupdel</command></term>
297 <listitem>
298 <para>Deletes the group with the given name</para>
299 <indexterm zone="ch-system-shadow groupdel">
300 <primary sortas="b-groupdel">groupdel</primary>
301 </indexterm>
302 </listitem>
303 </varlistentry>
304
305 <varlistentry id="groupmod">
306 <term><command>groupmod</command></term>
307 <listitem>
308 <para>Is used to modify the given group's name or GID</para>
309 <indexterm zone="ch-system-shadow groupmod">
310 <primary sortas="b-groupmod">groupmod</primary>
311 </indexterm>
312 </listitem>
313 </varlistentry>
314
315 <varlistentry id="grpck">
316 <term><command>grpck</command></term>
317 <listitem>
318 <para>Verifies the integrity of the group files
319 <filename>/etc/group</filename> and
320 <filename>/etc/gshadow</filename></para>
321 <indexterm zone="ch-system-shadow grpck">
322 <primary sortas="b-grpck">grpck</primary>
323 </indexterm>
324 </listitem>
325 </varlistentry>
326
327 <varlistentry id="grpconv">
328 <term><command>grpconv</command></term>
329 <listitem>
330 <para>Creates or updates the shadow group file from the normal
331 group file</para>
332 <indexterm zone="ch-system-shadow grpconv">
333 <primary sortas="b-grpconv">grpconv</primary>
334 </indexterm>
335 </listitem>
336 </varlistentry>
337
338 <varlistentry id="grpunconv">
339 <term><command>grpunconv</command></term>
340 <listitem>
341 <para>Updates <filename>/etc/group</filename> from
342 <filename>/etc/gshadow</filename> and then deletes the latter</para>
343 <indexterm zone="ch-system-shadow grpunconv">
344 <primary sortas="b-grpunconv">grpunconv</primary>
345 </indexterm>
346 </listitem>
347 </varlistentry>
348
349 <varlistentry id="lastlog">
350 <term><command>lastlog</command></term>
351 <listitem>
352 <para>Reports the most recent login of all users or of a
353 given user</para>
354 <indexterm zone="ch-system-shadow lastlog">
355 <primary sortas="b-lastlog">lastlog</primary>
356 </indexterm>
357 </listitem>
358 </varlistentry>
359
360 <varlistentry id="login">
361 <term><command>login</command></term>
362 <listitem>
363 <para>Is used by the system to let users sign on</para>
364 <indexterm zone="ch-system-shadow login">
365 <primary sortas="b-login">login</primary>
366 </indexterm>
367 </listitem>
368 </varlistentry>
369
370 <varlistentry id="logoutd">
371 <term><command>logoutd</command></term>
372 <listitem>
373 <para>Is a daemon used to enforce restrictions on log-on time
374 and ports</para>
375 <indexterm zone="ch-system-shadow logoutd">
376 <primary sortas="b-logoutd">logoutd</primary>
377 </indexterm>
378 </listitem>
379 </varlistentry>
380
381 <varlistentry id="newgrp">
382 <term><command>newgrp</command></term>
383 <listitem>
384 <para>Is used to change the current GID during a login session</para>
385 <indexterm zone="ch-system-shadow newgrp">
386 <primary sortas="b-newgrp">newgrp</primary>
387 </indexterm>
388 </listitem>
389 </varlistentry>
390
391 <varlistentry id="newusers">
392 <term><command>newusers</command></term>
393 <listitem>
394 <para>Is used to create or update an entire series of user
395 accounts</para>
396 <indexterm zone="ch-system-shadow newusers">
397 <primary sortas="b-newusers">newusers</primary>
398 </indexterm>
399 </listitem>
400 </varlistentry>
401
402 <varlistentry id="passwd">
403 <term><command>passwd</command></term>
404 <listitem>
405 <para>Is used to change the password for a user or group account</para>
406 <indexterm zone="ch-system-shadow passwd">
407 <primary sortas="b-passwd">passwd</primary>
408 </indexterm>
409 </listitem>
410 </varlistentry>
411
412 <varlistentry id="pwck">
413 <term><command>pwck</command></term>
414 <listitem>
415 <para>Verifies the integrity of the password files
416 <filename>/etc/passwd</filename> and
417 <filename>/etc/shadow</filename></para>
418 <indexterm zone="ch-system-shadow pwck">
419 <primary sortas="b-pwck">pwck</primary>
420 </indexterm>
421 </listitem>
422 </varlistentry>
423
424 <varlistentry id="pwconv">
425 <term><command>pwconv</command></term>
426 <listitem>
427 <para>Creates or updates the shadow password file from the normal
428 password file</para>
429 <indexterm zone="ch-system-shadow pwconv">
430 <primary sortas="b-pwconv">pwconv</primary>
431 </indexterm>
432 </listitem>
433 </varlistentry>
434
435 <varlistentry id="pwunconv">
436 <term><command>pwunconv</command></term>
437 <listitem>
438 <para>Updates <filename>/etc/passwd</filename> from
439 <filename>/etc/shadow</filename> and then deletes the latter</para>
440 <indexterm zone="ch-system-shadow pwunconv">
441 <primary sortas="b-pwunconv">pwunconv</primary>
442 </indexterm>
443 </listitem>
444 </varlistentry>
445
446 <varlistentry id="sg">
447 <term><command>sg</command></term>
448 <listitem>
449 <para>Executes a given command while the user's GID
450 is set to that of the given group</para>
451 <indexterm zone="ch-system-shadow sg">
452 <primary sortas="b-sg">sg</primary>
453 </indexterm>
454 </listitem>
455 </varlistentry>
456
457 <varlistentry id="su">
458 <term><command>su</command></term>
459 <listitem>
460 <para>Runs a shell with substitute user and group IDs</para>
461 <indexterm zone="ch-system-shadow su">
462 <primary sortas="b-su">su</primary>
463 </indexterm>
464 </listitem>
465 </varlistentry>
466
467 <varlistentry id="useradd">
468 <term><command>useradd</command></term>
469 <listitem>
470 <para>Creates a new user with the given name, or updates the default
471 new-user information</para>
472 <indexterm zone="ch-system-shadow useradd">
473 <primary sortas="b-useradd">useradd</primary>
474 </indexterm>
475 </listitem>
476 </varlistentry>
477
478 <varlistentry id="userdel">
479 <term><command>userdel</command></term>
480 <listitem>
481 <para>Deletes the given user account</para>
482 <indexterm zone="ch-system-shadow userdel">
483 <primary sortas="b-userdel">userdel</primary>
484 </indexterm>
485 </listitem>
486 </varlistentry>
487
488 <varlistentry id="usermod">
489 <term><command>usermod</command></term>
490 <listitem>
491 <para>Is used to modify the given user's login name, User
492 Identification (UID), shell, initial group, home directory, etc.</para>
493 <indexterm zone="ch-system-shadow usermod">
494 <primary sortas="b-usermod">usermod</primary>
495 </indexterm>
496 </listitem>
497 </varlistentry>
498
499 <varlistentry id="vigr">
500 <term><command>vigr</command></term>
501 <listitem>
502 <para>Edits the <filename>/etc/group</filename> or
503 <filename>/etc/gshadow</filename> files</para>
504 <indexterm zone="ch-system-shadow vigr">
505 <primary sortas="b-vigr">vigr</primary>
506 </indexterm>
507 </listitem>
508 </varlistentry>
509
510 <varlistentry id="vipw">
511 <term><command>vipw</command></term>
512 <listitem>
513 <para>Edits the <filename>/etc/passwd</filename> or
514 <filename>/etc/shadow</filename> files</para>
515 <indexterm zone="ch-system-shadow vipw">
516 <primary sortas="b-vipw">vipw</primary>
517 </indexterm>
518 </listitem>
519 </varlistentry>
520
521 <varlistentry id="libshadow">
522 <term><filename class="libraryfile">libshadow</filename></term>
523 <listitem>
524 <para>Contains functions used by most programs in this package</para>
525 <indexterm zone="ch-system-shadow libshadow">
526 <primary sortas="c-libshadow">libshadow</primary>
527 </indexterm>
528 </listitem>
529 </varlistentry>
530
531 </variablelist>
532
533 </sect2>
534
535</sect1>
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