1 .\" Copyright (c) 1996 David Nugent <davidn@blaze.net.au>
2 .\" All rights reserved.
4 .\" Redistribution and use in source and binary forms, with or without
5 .\" modification, is permitted provided that the following conditions
7 .\" 1. Redistributions of source code must retain the above copyright
8 .\" notice immediately at the beginning of the file, without modification,
9 .\" this list of conditions, and the following disclaimer.
10 .\" 2. Redistributions in binary form must reproduce the above copyright
11 .\" notice, this list of conditions and the following disclaimer in the
12 .\" documentation and/or other materials provided with the distribution.
13 .\" 3. This work was done expressly for inclusion into FreeBSD. Other use
14 .\" is permitted provided this notation is included.
15 .\" 4. Absolutely no warranty of function or purpose is made by the author
17 .\" 5. Modifications may be freely made to this file providing the above
18 .\" conditions are met.
27 .Nd login class capability database
33 contains various attributes and capabilities of login classes.
34 A login class (an optional annotation against each record in the user
36 .Pa /etc/master.passwd )
37 determines session accounting, resource limits and user environment settings.
38 It is used by various programs in the system to set up a user's login
39 environment and to enforce policy, accounting and administrative restrictions.
40 It also provides the means by which users are able to be
41 authenticated to the system and the types of authentication available.
42 Attributes in addition to the ones described here are available with
45 A special record "default" in the system user class capability database
47 is used automatically for any
48 non-root user without a valid login class in
49 .Pa /etc/master.passwd .
50 A user with a uid of 0 without a valid login class will use the record
51 "root" if it exists, or "default" if not.
55 users may individually create a file called
57 in their home directory using the same format, consisting of a single
58 entry with a record id of "me".
59 If present, this file is used by
61 to set user-defined environment settings which override those specified
62 in the system login capabilities database.
63 Only a subset of login capabilities may be overridden, typically those
64 which do not involve authentication, resource limits and accounting.
66 Records in a class capabilities database consist of a number of
67 colon-separated fields.
68 The first entry for each record gives one or more names that a record is
69 to be known by, each separated by a '|' character.
70 The first name is the most common abbreviation.
71 The last name given should be a long name that is more descriptive
72 of the capability entry, and all others are synonyms.
73 All names but the last should be in lower case and contain no blanks;
74 the last name may contain upper case characters and blanks for
81 is an out of the box configuration.
82 Whenever changes to this, or
85 file are made, the modifications will not be picked up until
87 is used to compile the file into a database.
88 This database file will have a
90 extension and is accessed through
94 for a more in-depth description of the format of a capability database.
96 Fields within each record in the database follow the
98 conventions for boolean, type string
102 although type numeric is deprecated in favour of the string format and
103 either form is accepted for a numeric datum.
104 Values fall into the following categories:
105 .Bl -tag -width "program"
107 If the name is present, then the boolean value is true; otherwise, it is
110 Path name to a data file
112 Path name to an executable file
114 A list of values (or pairs of values) separated by commas or spaces
116 A space or comma separated list of path names, following the usual csh
117 conventions (leading tilde with and without username being expanded to
118 home directories etc.)
120 A numeric value, either decimal (default), hexadecimal (with leading 0x),
121 or octal (with a leading 0).
122 With a numeric type, only one numeric value is allowed.
123 Numeric types may also be specified in string format (i.e., the capability
124 tag being delimited from the value by '=' instead of '#').
125 Whichever method is used, then all records in the database must use the
126 same method to allow values to be correctly overridden in interpolated
129 A number which expresses a size.
130 The default interpretation of a value is the number of bytes, but a
131 suffix may specify alternate units:
132 .Bl -tag -offset indent -compact -width xxxx
134 explicitly selects 512-byte blocks
136 selects kilobytes (1024 bytes)
138 specifies a multiplier of 1 megabyte (1048576 bytes),
140 specifies units of gigabytes, and
142 represents terabytes.
144 A size value is a numeric quantity and case of the suffix is not significant.
145 Concatenated values are added together.
147 A period of time, by default in seconds.
148 A prefix may specify a different unit:
149 .Bl -tag -offset indent -compact -width xxxx
151 indicates the number of 365 day years,
153 indicates the number of weeks,
159 the number of minutes, and
161 the number of seconds.
163 Concatenated values are added together.
164 For example, 2 hours and 40 minutes may be written either as
165 9600s, 160m or 2h40m.
168 The usual convention to interpolate capability entries using the special
170 notation may be used.
172 .Bl -column coredumpsize indent indent
173 .It Sy "Name Type Notes Description
174 .It "coredumpsize size Maximum coredump size limit.
175 .It "cputime time CPU usage limit.
176 .It "datasize size Maximum data size limit.
177 .It "filesize size Maximum file size limit.
178 .It "maxproc number Maximum number of processes.
179 .It "memorylocked size Maximum locked in core memory size limit.
180 .It "memoryuse size Maximum of core memory use size limit.
181 .It "openfiles number Maximum number of open files per process.
182 .It "sbsize size Maximum permitted socketbuffer size.
183 .It "vmemoryuse size Maximum permitted total VM usage per process.
184 .It "stacksize size Maximum stack size limit.
187 These resource limit entries actually specify both the maximum
188 and current limits (see
190 The current (soft) limit is the one normally used, although the user is
191 permitted to increase the current limit to the maximum (hard) limit.
192 The maximum and current limits may be specified individually by appending a
193 -max or -cur to the capability name.
195 .Bl -column ignorenologin indent xbinxxusrxbin
196 .It Sy "Name Type Notes Description
197 .It "charset string Set $MM_CHARSET environment variable to the specified
199 .It "hushlogin bool false Same as having a ~/.hushlogin file.
200 .It "ignorenologin bool false Login not prevented by nologin.
201 .It "ftp-chroot bool false Limit FTP access with
205 directory of the user.
209 .It "label string Default MAC policy; see
211 .It "lang string Set $LANG environment variable to the specified value.
212 .It "manpath path Default search path for manpages.
213 .It "nocheckmail bool false Display mail status at login.
214 .It "nologin file If the file exists it will be displayed and
215 the login session will be terminated.
216 .It "path path /bin /usr/bin Default search path.
217 .It "priority number Initial priority (nice) level.
218 .It "requirehome bool false Require a valid home directory to login.
219 .It "setenv list A comma-separated list of environment variables and
220 values to which they are to be set.
221 .It "shell prog Session shell to execute rather than the
222 shell specified in the passwd file.
223 The SHELL environment variable will
224 contain the shell specified in the password file.
225 .It "term string Default terminal type if not able to determine
227 .It "timezone string Default value of $TZ environment variable.
228 .It "umask number 022 Initial umask. Should always have a leading 0 to
229 ensure octal interpretation.
230 .It "welcome file /etc/motd File containing welcome message.
233 .Bl -column passwd_prompt indent indent
234 .It Sy "Name Type Notes Description
235 .\" .It "approve program Program to approve login.
236 .It "copyright file File containing additional copyright information
237 .It "host.allow list List of remote host wildcards from which users in
238 the class may access.
239 .It "host.deny list List of remote host wildcards from which users
240 in the class may not access.
241 .It "login_prompt string The login prompt given by
243 .It "login-backoff number 3 The number of login attempts
244 allowed before the backoff delay is inserted after each subsequent
246 .It "login-retries number 10 The number of login attempts
247 allowed before the login fails.
248 .It "passwd_format string md5 The encryption format that new or
249 changed passwords will use.
250 Valid values include "des", "md5" and "blf".
253 NIS server should probably use "des".
254 .It "passwd_prompt string The password prompt presented by
256 .It "times.allow list List of time periods during which
258 .It "times.deny list List of time periods during which logins are
260 .It "ttys.allow list List of ttys and ttygroups which users
261 in the class may use for access.
262 .It "ttys.deny list List of ttys and ttygroups which users
263 in the class may not use for access.
264 .It "warnexpire time Advance notice for pending account expiry.
265 .It "warnpassword time Advance notice for pending password expiry.
266 .\".It "widepasswords bool false Use the wide password format. The wide password
267 .\" format allows up to 128 significant characters in the password.
270 These fields are intended to be used by
272 and other programs in the login authentication system.
274 Capabilities that set environment variables are scanned for both
278 characters, which are substituted for a user's home directory and name
280 To pass these characters literally into the environment variable, escape
281 the character by preceding it with a backslash '\\'.
287 entries are comma separated lists used for checking remote access to the system,
288 and consist of a list of hostnames and/or IP addresses against which remote
289 network logins are checked.
290 Items in these lists may contain wildcards in the form used by shell programs
291 for wildcard matching (See
293 for details on the implementation).
294 The check on hosts is made against both the remote system's Internet address
295 and hostname (if available).
296 If both lists are empty or not specified, then logins from any remote host
298 If host.allow contains one or more hosts, then only remote systems matching
299 any of the items in that list are allowed to log in.
300 If host.deny contains one or more hosts, then a login from any matching hosts
307 entries consist of a comma-separated list of time periods during which the users
308 in a class are allowed to be logged in.
309 These are expressed as one or more day codes followed by a start and end times
310 expressed in 24 hour format, separated by a hyphen or dash.
311 For example, MoThSa0200-1300 translates to Monday, Thursday and Saturday between
312 the hours of 2 am and 1 p.m..
313 If both of these time lists are empty, users in the class are allowed access at
317 is specified, then logins are only allowed during the periods given.
320 is specified, then logins are denied during the periods given, regardless of whether
321 one of the periods specified in
327 enforces only that the actual login falls within periods allowed by these entries.
328 Further enforcement over the life of a session requires a separate daemon to
329 monitor transitions from an allowed period to a non-allowed one.
335 entries contain a comma-separated list of tty devices (without the /dev/ prefix)
336 that a user in a class may use to access the system, and/or a list of ttygroups
341 for information on ttygroups).
342 If neither entry exists, then the choice of login device used by the user is
346 is specified, then the user is restricted only to ttys in the given
347 group or device list.
350 is specified, then the user is prevented from using the specified devices or
351 devices in the group.
352 If both lists are given and are non-empty, the user is restricted to those
353 devices allowed by ttys.allow that are not available by ttys.deny.
359 facilities for enforcing restrictions on password quality, which used
362 have been superseded by the
365 .Sh RESERVED CAPABILITIES
366 The following capabilities are reserved for the purposes indicated and
367 may be supported by third-party software.
368 They are not implemented in the base system.
369 .Bl -column host.accounted indent indent
370 .It Sy "Name Type Notes Description
371 .It "accounted bool false Enable session time accounting for all users
373 .It "autodelete time Time after expiry when account is auto-deleted.
374 .It "bootfull bool false Enable 'boot only if ttygroup is full' strategy
375 when terminating sessions.
376 .It "daytime time Maximum login time per day.
377 .It "expireperiod time Time for expiry allocation.
378 .It "graceexpire time Grace days for expired account.
379 .It "gracetime time Additional grace login time allowed.
380 .It "host.accounted list List of remote host wildcards from which
381 login sessions will be accounted.
382 .It "host.exempt list List of remote host wildcards from which
383 login session accounting is exempted.
384 .It "idletime time Maximum idle time before logout.
385 .It "minpasswordlen number 6 The minimum length a local
387 .It "mixpasswordcase bool true Whether
389 will warn the user if an all lower case password is entered.
390 .It "monthtime time Maximum login time per month.
391 .It "passwordtime time Used by
393 to set next password expiry date.
394 .It "refreshtime time New time allowed on account refresh.
395 .It "refreshperiod str How often account time is refreshed.
396 .It "sessiontime time Maximum login time per session.
397 .It "sessionlimit number Maximum number of concurrent
398 login sessions on ttys in any group.
399 .It "ttys.accounted list List of ttys and ttygroups for which
400 login accounting is active.
401 .It "ttys.exempt list List of ttys and ttygroups for which login accounting
403 .It "warntime time Advance notice for pending out-of-time.
404 .It "weektime time Maximum login time per week.
411 fields operate in a similar manner to
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