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
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12 .\" documentation and/or other materials provided with the distribution.
13 .\" 3. This work was done expressly for inclusion into FreeBSD. Other use
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15 .\" 4. Absolutely no warranty of function or purpose is made by the author
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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
79 for a more in-depth description of the format of a capability database.
81 Fields within each record in the database follow the
83 conventions for boolean, type string
87 although type numeric is deprecated in favour of the string format and
88 either form is accepted for a numeric datum.
89 Values fall into the following categories:
90 .Bl -tag -width "program"
92 If the name is present, then the boolean value is true; otherwise, it is
95 Path name to a data file
97 Path name to an executable file
99 A list of values (or pairs of values) separated by commas or spaces
101 A space or comma separated list of path names, following the usual csh
102 conventions (leading tilde with and without username being expanded to
103 home directories etc.)
105 A numeric value, either decimal (default), hexadecimal (with leading 0x),
106 or octal (with a leading 0).
107 With a numeric type, only one numeric value is allowed.
108 Numeric types may also be specified in string format (i.e., the capability
109 tag being delimited from the value by '=' instead of '#').
110 Whichever method is used, then all records in the database must use the
111 same method to allow values to be correctly overridden in interpolated
114 A number which expresses a size.
115 The default interpretation of a value is the number of bytes, but a
116 suffix may specify alternate units:
117 .Bl -tag -offset indent -compact -width xxxx
119 explicitly selects 512-byte blocks
121 selects kilobytes (1024 bytes)
123 specifies a multiplier of 1 megabyte (1048576 bytes),
125 specifies units of gigabytes, and
127 represents terabytes.
129 A size value is a numeric quantity and case of the suffix is not significant.
130 Concatenated values are added together.
132 A period of time, by default in seconds.
133 A prefix may specify a different unit:
134 .Bl -tag -offset indent -compact -width xxxx
136 indicates the number of 365 day years,
138 indicates the number of weeks,
144 the number of minutes, and
146 the number of seconds.
148 Concatenated values are added together.
149 For example, 2 hours and 40 minutes may be written either as
150 9600s, 160m or 2h40m.
153 The usual convention to interpolate capability entries using the special
155 notation may be used.
157 .Bl -column coredumpsize indent indent
158 .It Sy "Name Type Notes Description
159 .It "coredumpsize size Maximum coredump size limit.
160 .It "cputime time CPU usage limit.
161 .It "datasize size Maximum data size limit.
162 .It "filesize size Maximum file size limit.
163 .It "maxproc number Maximum number of processes.
164 .It "memorylocked size Maximum locked in core memory size limit.
165 .It "memoryuse size Maximum of core memory use size limit.
166 .It "openfiles number Maximum number of open files per process.
167 .It "sbsize size Maximum permitted socketbuffer size.
168 .It "vmemoryuse size Maximum permitted total VM usage per process.
169 .It "stacksize size Maximum stack size limit.
172 These resource limit entries actually specify both the maximum
173 and current limits (see
175 The current (soft) limit is the one normally used, although the user is
176 permitted to increase the current limit to the maximum (hard) limit.
177 The maximum and current limits may be specified individually by appending a
178 -max or -cur to the capability name.
180 .Bl -column ignorenologin indent xbinxxusrxbin
181 .It Sy "Name Type Notes Description
182 .It "charset string Set $MM_CHARSET environment variable to the specified
184 .It "hushlogin bool false Same as having a ~/.hushlogin file.
185 .It "ignorenologin bool false Login not prevented by nologin.
186 .It "ftp-chroot bool false Limit FTP access with
190 directory of the user.
194 .It "label string Default MAC policy; see
196 .It "lang string Set $LANG environment variable to the specified value.
197 .It "manpath path Default search path for manpages.
198 .It "nocheckmail bool false Display mail status at login.
199 .It "nologin file If the file exists it will be displayed and
200 the login session will be terminated.
201 .It "path path /bin /usr/bin Default search path.
202 .It "priority number Initial priority (nice) level.
203 .It "requirehome bool false Require a valid home directory to login.
204 .It "setenv list A comma-separated list of environment variables and
205 values to which they are to be set.
206 .It "shell prog Session shell to execute rather than the
207 shell specified in the passwd file.
208 The SHELL environment variable will
209 contain the shell specified in the password file.
210 .It "term string Default terminal type if not able to determine
212 .It "timezone string Default value of $TZ environment variable.
213 .It "umask number 022 Initial umask. Should always have a leading 0 to
214 ensure octal interpretation.
215 .It "welcome file /etc/motd File containing welcome message.
218 .Bl -column passwd_prompt indent indent
219 .It Sy "Name Type Notes Description
220 .\" .It "approve program Program to approve login.
221 .It "copyright file File containing additional copyright information
222 .It "host.allow list List of remote host wildcards from which users in
223 the class may access.
224 .It "host.deny list List of remote host wildcards from which users
225 in the class may not access.
226 .It "login_prompt string The login prompt given by
228 .It "login-backoff number 3 The number of login attempts
229 allowed before the backoff delay is inserted after each subsequent
231 .It "login-retries number 10 The number of login attempts
232 allowed before the login fails.
233 .It "passwd_format string md5 The encryption format that new or
234 changed passwords will use.
235 Valid values include "des", "md5" and "blf".
238 NIS server should probably use "des".
239 .It "passwd_prompt string The password prompt presented by
241 .It "times.allow list List of time periods during which
243 .It "times.deny list List of time periods during which logins are
245 .It "ttys.allow list List of ttys and ttygroups which users
246 in the class may use for access.
247 .It "ttys.deny list List of ttys and ttygroups which users
248 in the class may not use for access.
249 .It "warnexpire time Advance notice for pending account expiry.
250 .It "warnpassword time Advance notice for pending password expiry.
251 .\".It "widepasswords bool false Use the wide password format. The wide password
252 .\" format allows up to 128 significant characters in the password.
255 These fields are intended to be used by
257 and other programs in the login authentication system.
259 Capabilities that set environment variables are scanned for both
263 characters, which are substituted for a user's home directory and name
265 To pass these characters literally into the environment variable, escape
266 the character by preceding it with a backslash '\\'.
272 entries are comma separated lists used for checking remote access to the system,
273 and consist of a list of hostnames and/or IP addresses against which remote
274 network logins are checked.
275 Items in these lists may contain wildcards in the form used by shell programs
276 for wildcard matching (See
278 for details on the implementation).
279 The check on hosts is made against both the remote system's Internet address
280 and hostname (if available).
281 If both lists are empty or not specified, then logins from any remote host
283 If host.allow contains one or more hosts, then only remote systems matching
284 any of the items in that list are allowed to log in.
285 If host.deny contains one or more hosts, then a login from any matching hosts
292 entries consist of a comma-separated list of time periods during which the users
293 in a class are allowed to be logged in.
294 These are expressed as one or more day codes followed by a start and end times
295 expressed in 24 hour format, separated by a hyphen or dash.
296 For example, MoThSa0200-1300 translates to Monday, Thursday and Saturday between
297 the hours of 2 am and 1 p.m..
298 If both of these time lists are empty, users in the class are allowed access at
302 is specified, then logins are only allowed during the periods given.
305 is specified, then logins are denied during the periods given, regardless of whether
306 one of the periods specified in
312 enforces only that the actual login falls within periods allowed by these entries.
313 Further enforcement over the life of a session requires a separate daemon to
314 monitor transitions from an allowed period to a non-allowed one.
320 entries contain a comma-separated list of tty devices (without the /dev/ prefix)
321 that a user in a class may use to access the system, and/or a list of ttygroups
326 for information on ttygroups).
327 If neither entry exists, then the choice of login device used by the user is
331 is specified, then the user is restricted only to ttys in the given
332 group or device list.
335 is specified, then the user is prevented from using the specified devices or
336 devices in the group.
337 If both lists are given and are non-empty, the user is restricted to those
338 devices allowed by ttys.allow that are not available by ttys.deny.
344 facilities for enforcing restrictions on password quality, which used
347 have been superseded by the
350 .Sh RESERVED CAPABILITIES
351 The following capabilities are reserved for the purposes indicated and
352 may be supported by third-party software.
353 They are not implemented in the base system.
354 .Bl -column host.accounted indent indent
355 .It Sy "Name Type Notes Description
356 .It "accounted bool false Enable session time accounting for all users
358 .It "autodelete time Time after expiry when account is auto-deleted.
359 .It "bootfull bool false Enable 'boot only if ttygroup is full' strategy
360 when terminating sessions.
361 .It "daytime time Maximum login time per day.
362 .It "expireperiod time Time for expiry allocation.
363 .It "graceexpire time Grace days for expired account.
364 .It "gracetime time Additional grace login time allowed.
365 .It "host.accounted list List of remote host wildcards from which
366 login sessions will be accounted.
367 .It "host.exempt list List of remote host wildcards from which
368 login session accounting is exempted.
369 .It "idletime time Maximum idle time before logout.
370 .It "minpasswordlen number 6 The minimum length a local
372 .It "mixpasswordcase bool true Whether
374 will warn the user if an all lower case password is entered.
375 .It "monthtime time Maximum login time per month.
376 .It "passwordtime time Used by
378 to set next password expiry date.
379 .It "refreshtime time New time allowed on account refresh.
380 .It "refreshperiod str How often account time is refreshed.
381 .It "sessiontime time Maximum login time per session.
382 .It "sessionlimit number Maximum number of concurrent
383 login sessions on ttys in any group.
384 .It "ttys.accounted list List of ttys and ttygroups for which
385 login accounting is active.
386 .It "ttys.exempt list List of ttys and ttygroups for which login accounting
388 .It "warntime time Advance notice for pending out-of-time.
389 .It "weektime time Maximum login time per week.
396 fields operate in a similar manner to