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
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.
43 A special record "default" in the system user class capability database
45 is used automatically for any
46 non-root user without a valid login class in
47 .Pa /etc/master.passwd .
48 A user with a uid of 0 without a valid login class will use the record
49 "root" if it exists, or "default" if not.
53 users may individually create a file called
55 in their home directory using the same format, consisting of a single
56 entry with a record id of "me".
57 If present, this file is used by
59 to set user-defined environment settings which override those specified
60 in the system login capabilities database.
61 Only a subset of login capabilities may be overridden, typically those
62 which do not involve authentication, resource limits and accounting.
64 Records in a class capabilities database consist of a number of
65 colon-separated fields.
66 The first entry for each record gives one or more names that a record is
67 to be known by, each separated by a '|' character.
68 The first name is the most common abbreviation.
69 The last name given should be a long name that is more descriptive
70 of the capability entry, and all others are synonyms.
71 All names but the last should be in lower case and contain no blanks;
72 the last name may contain upper case characters and blanks for
77 for a more in-depth description of the format of a capability database.
79 Fields within each record in the database follow the
81 conventions for boolean, type string
85 although type numeric is depreciated in favour of the string format and
86 either form is accepted for a numeric datum.
87 Values fall into the following categories:
88 .Bl -tag -width "program"
90 If the name is present, then the boolean value is true; otherwise, it is
93 Path name to a data file
95 Path name to an executable file
97 A list of values (or pairs of values) separated by commas or spaces
99 A space or comma separated list of path names, following the usual csh
100 conventions (leading tilde with and without username being expanded to
101 home directories etc.)
103 A numeric value, either decimal (default), hexadecimal (with leading 0x),
104 or octal (with a leading 0).
105 With a numeric type, only one numeric value is allowed.
106 Numeric types may also be specified in string format (ie. the capability
107 tag being delimited from the value by '=' instead of '#').
108 Whichever method is used, then all records in the database must use the
109 same method to allow values to be correctly overridden in interpolated
112 A number which expresses a size.
113 The default interpretation of a value is the number of bytes, but a
114 suffix may specify alternate units:
115 .Bl -tag -offset indent -compact -width xxxx
117 explicitly selects 512-byte blocks
119 selects kilobytes (1024 bytes)
121 specifies a multiplier of 1 megabyte (1048576 bytes),
123 specifies units of gigabytes, and
125 represents terabytes.
127 A size value is a numeric quantity and case of the suffix is not significant.
128 Concatenated values are added together.
130 A period of time, by default in seconds.
131 A prefix may specify a different unit:
132 .Bl -tag -offset indent -compact -width xxxx
134 indicates the number of 365 day years,
136 indicates the number of weeks,
142 the number of minutes, and
144 the number of seconds.
146 Concatenated values are added together.
147 For example, 2 hours and 40 minutes may be written either as
148 9600s, 160m or 2h40m.
151 The usual convention to interpolate capability entries using the special
153 notation may be used.
155 .Bl -column coredumpsize indent indent
156 .It Sy "Name Type Notes Description
157 .It "coredumpsize size Maximum coredump size limit.
158 .It "cputime time CPU usage limit.
159 .It "datasize size Maximum data size limit.
160 .It "filesize size Maximum file size limit.
161 .It "maxproc number Maximum number of processes.
162 .It "memorylocked size Maximum locked in core memory size limit.
163 .It "memoryuse size Maximum of core memory use size limit.
164 .It "openfiles number Maximum number of open files per process.
165 .It "sbsize size Maximum permitted socketbuffer size.
166 .It "stacksize size Maximum stack size limit.
169 These resource limit entries actually specify both the maximum
170 and current limits (see
172 The current (soft) limit is the one normally used, although the user is
173 permitted to increase the current limit to the maximum (hard) limit.
174 The maximum and current limits may be specified individually by appending a
175 -max or -cur to the capability name.
177 .Bl -column ignorenologin indent xbinxxusrxbin
178 .It Sy "Name Type Notes Description
179 .It "charset string Set $MM_CHARSET environment variable to the specified
181 .It "hushlogin bool false Same as having a ~/.hushlogin file.
182 .It "ignorenologin bool false Login not prevented by nologin.
183 .It "lang string Set $LANG environment variable to the specified value.
184 .It "manpath path Default search path for manpages.
185 .It "nocheckmail bool false Display mail status at login.
186 .It "nologin file If the file exists it will be displayed and
187 the login session will be terminated.
188 .It "path path /bin /usr/bin Default search path.
189 .It "priority number Initial priority (nice) level.
190 .It "requirehome bool false Require a valid home directory to login.
191 .It "setenv list A comma-separated list of environment variables and
192 values to which they are to be set.
193 .It "shell prog Session shell to execute rather than the
194 shell specified in the passwd file.
195 The SHELL environment variable will
196 contain the shell specified in the password file.
197 .It "term string Default terminal type if not able to determine
199 .It "timezone string Default value of $TZ environment variable.
200 .It "umask number 022 Initial umask. Should always have a leading 0 to
201 ensure octal interpretation.
202 .It "welcome file /etc/motd File containing welcome message.
205 .Bl -column minpasswordlen indent indent
206 .It Sy "Name Type Notes Description
207 .\" .It "approve program Program to approve login.
208 .It "copyright file File containing additional copyright information
209 .It "host.allow list List of remote host wildcards from which users in
210 the class may access.
211 .It "host.deny list List of remote host wildcards from which users
212 in the class may not access.
213 .It "login_prompt string The login prompt given by
215 .It "minpasswordlen number 6 The minimum length a local password
217 .It "mixpasswordcase bool true Whether
219 will warn the user if an all lower case password is entered.
220 .It "passwd_format string md5 The encryption format that new or
221 changed passwords will use.
222 Valid values include "des", "md5" and "blf".
225 NIS server should probably use "des".
226 .It "passwd_prompt string The password prompt presented by
228 .It "times.allow list List of time periods during which
230 .It "times.deny list List of time periods during which logins are
232 .It "ttys.allow list List of ttys and ttygroups which users
233 in the class may use for access.
234 .It "ttys.deny list List of ttys and ttygroups which users
235 in the class may not use for access.
236 .\".It "widepasswords bool false Use the wide password format. The wide password
237 .\" format allows up to 128 significant characters in the password.
240 These fields are intended to be used by
242 and other programs in the login authentication system.
244 Capabilities that set environment variables are scanned for both
248 characters, which are substituted for a user's home directory and name
250 To pass these characters literally into the environment variable, escape
251 the character by preceding it with a backslash '\\'.
257 entries are comma separated lists used for checking remote access to the system,
258 and consist of a list of hostnames and/or IP addresses against which remote
259 network logins are checked.
260 Items in these lists may contain wildcards in the form used by shell programs
261 for wildcard matching (See
263 for details on the implementation).
264 The check on hosts is made against both the remote system's Internet address
265 and hostname (if available).
266 If both lists are empty or not specified, then logins from any remote host
268 If host.allow contains one or more hosts, then only remote systems matching
269 any of the items in that list are allowed to log in.
270 If host.deny contains one or more hosts, then a login from any matching hosts
277 entries consist of a comma-separated list of time periods during which the users
278 in a class are allowed to be logged in.
279 These are expressed as one or more day codes followed by a start and end times
280 expressed in 24 hour format, separated by a hyphen or dash.
281 For example, MoThSa0200-1300 translates to Monday, Thursday and Saturday between
282 the hours of 2 am and 1 p.m..
283 If both of these time lists are empty, users in the class are allowed access at
287 is specified, then logins are only allowed during the periods given.
290 is specified, then logins are denied during the periods given, regardless of whether
291 one of the periods specified in
297 enforces only that the actual login falls within periods allowed by these entries.
298 Further enforcement over the life of a session requires a separate daemon to
299 monitor transitions from an allowed period to a non-allowed one.
305 entries contain a comma-separated list of tty devices (without the /dev/ prefix)
306 that a user in a class may use to access the system, and/or a list of ttygroups
311 for information on ttygroups).
312 If neither entry exists, then the choice of login device used by the user is
316 is specified, then the user is restricted only to ttys in the given
317 group or device list.
320 is specified, then the user is prevented from using the specified devices or
321 devices in the group.
322 If both lists are given and are non-empty, the user is restricted to those
323 devices allowed by ttys.allow that are not available by ttys.deny.
324 .Sh ACCOUNTING LIMITS
325 .Bl -column host.accounted indent indent
326 .It Sy "Name Type Notes Description
327 .It "accounted bool false Enable session time accounting for all users
329 .It "autodelete time Time after expiry when account is auto-deleted.
330 .It "bootfull bool false Enable 'boot only if ttygroup is full' strategy
331 when terminating sessions.
332 .It "daytime time Maximum login time per day.
333 .It "expireperiod time Time for expiry allocation.
334 .It "graceexpire time Grace days for expired account.
335 .It "gracetime time Additional grace login time allowed.
336 .It "host.accounted list List of remote host wildcards from which
337 login sessions will be accounted.
338 .It "host.exempt list List of remote host wildcards from which
339 login session accounting is exempted.
340 .It "idletime time Maximum idle time before logout.
341 .It "monthtime time Maximum login time per month.
342 .It "passwordtime time Used by
344 to set next password expiry date.
345 .It "refreshtime time New time allowed on account refresh.
346 .It "refreshperiod str How often account time is refreshed.
347 .It "sessiontime time Maximum login time per session.
348 .It "sessionlimit number Maximum number of concurrent
349 login sessions on ttys in any group.
350 .It "ttys.accounted list List of ttys and ttygroups for which
351 login accounting is active.
352 .It "ttys.exempt list List of ttys and ttygroups for which login accounting
354 .It "warnexpire time Advance notice for pending account expiry.
355 .It "warnpassword time Advance notice for pending password expiry.
356 .It "warntime time Advance notice for pending out-of-time.
357 .It "weektime time Maximum login time per week.
360 These fields are used by the time accounting system, which regulates,
361 controls and records user login access.
367 fields operate in a similar manner to