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
77 Note that since a colon
79 is used to separate capability entries, a
81 escape sequence must be used to embed a literal colon in the
82 value or name of a capability.
88 is an out of the box configuration.
89 Whenever changes to this, or
92 file are made, the modifications will not be picked up until
94 is used to compile the file into a database.
95 This database file will have a
97 extension and is accessed through
101 for a more in-depth description of the format of a capability database.
103 Fields within each record in the database follow the
105 conventions for boolean, type string
109 although type numeric is deprecated in favour of the string format and
110 either form is accepted for a numeric datum.
111 Values fall into the following categories:
112 .Bl -tag -width "program"
114 If the name is present, then the boolean value is true; otherwise, it is
117 Path name to a data file
119 Path name to an executable file
121 A list of values (or pairs of values) separated by commas or spaces
123 A space or comma separated list of path names, following the usual csh
124 conventions (leading tilde with and without username being expanded to
125 home directories etc.)
127 A numeric value, either decimal (default), hexadecimal (with leading 0x),
128 or octal (with a leading 0).
129 With a numeric type, only one numeric value is allowed.
130 Numeric types may also be specified in string format (i.e., the capability
131 tag being delimited from the value by '=' instead of '#').
132 Whichever method is used, then all records in the database must use the
133 same method to allow values to be correctly overridden in interpolated
136 A number which expresses a size.
137 The default interpretation of a value is the number of bytes, but a
138 suffix may specify alternate units:
139 .Bl -tag -offset indent -compact -width xxxx
141 explicitly selects 512-byte blocks
143 selects kilobytes (1024 bytes)
145 specifies a multiplier of 1 megabyte (1048576 bytes),
147 specifies units of gigabytes, and
149 represents terabytes.
151 A size value is a numeric quantity and case of the suffix is not significant.
152 Concatenated values are added together.
154 A period of time, by default in seconds.
155 A prefix may specify a different unit:
156 .Bl -tag -offset indent -compact -width xxxx
158 indicates the number of 365 day years,
160 indicates the number of weeks,
166 the number of minutes, and
168 the number of seconds.
170 Concatenated values are added together.
171 For example, 2 hours and 40 minutes may be written either as
172 9600s, 160m or 2h40m.
175 The usual convention to interpolate capability entries using the special
177 notation may be used.
179 .Bl -column coredumpsize indent indent
180 .It Sy "Name Type Notes Description
181 .It "coredumpsize size Maximum coredump size limit.
182 .It "cputime time CPU usage limit.
183 .It "datasize size Maximum data size limit.
184 .It "filesize size Maximum file size limit.
185 .It "maxproc number Maximum number of processes.
186 .It "memorylocked size Maximum locked in core memory size limit.
187 .It "memoryuse size Maximum of core memory use size limit.
188 .It "openfiles number Maximum number of open files per process.
189 .It "sbsize size Maximum permitted socketbuffer size.
190 .It "vmemoryuse size Maximum permitted total VM usage per process.
191 .It "stacksize size Maximum stack size limit.
194 These resource limit entries actually specify both the maximum
195 and current limits (see
197 The current (soft) limit is the one normally used, although the user is
198 permitted to increase the current limit to the maximum (hard) limit.
199 The maximum and current limits may be specified individually by appending a
200 -max or -cur to the capability name.
202 .Bl -column ignorenologin indent xbinxxusrxbin
203 .It Sy "Name Type Notes Description
204 .It "charset string Set $MM_CHARSET environment variable to the specified
206 .It "hushlogin bool false Same as having a ~/.hushlogin file.
207 .It "ignorenologin bool false Login not prevented by nologin.
208 .It "ftp-chroot bool false Limit FTP access with
212 directory of the user.
216 .It "label string Default MAC policy; see
218 .It "lang string Set $LANG environment variable to the specified value.
219 .It "manpath path Default search path for manpages.
220 .It "nocheckmail bool false Display mail status at login.
221 .It "nologin file If the file exists it will be displayed and
222 the login session will be terminated.
223 .It "path path /bin /usr/bin Default search path.
224 .It "priority number Initial priority (nice) level.
225 .It "requirehome bool false Require a valid home directory to login.
226 .It "setenv list A comma-separated list of environment variables and
227 values to which they are to be set.
228 .It "shell prog Session shell to execute rather than the
229 shell specified in the passwd file.
230 The SHELL environment variable will
231 contain the shell specified in the password file.
232 .It "term string Default terminal type if not able to determine
234 .It "timezone string Default value of $TZ environment variable.
235 .It "umask number 022 Initial umask. Should always have a leading 0 to
236 ensure octal interpretation.
237 .It "welcome file /etc/motd File containing welcome message.
240 .Bl -column passwd_prompt indent indent
241 .It Sy "Name Type Notes Description
242 .\" .It "approve program Program to approve login.
243 .It "copyright file File containing additional copyright information
244 .It "host.allow list List of remote host wildcards from which users in
245 the class may access.
246 .It "host.deny list List of remote host wildcards from which users
247 in the class may not access.
248 .It "login_prompt string The login prompt given by
250 .It "login-backoff number 3 The number of login attempts
251 allowed before the backoff delay is inserted after each subsequent
253 The backoff delay is the number of tries above
255 multiplied by 5 seconds.
256 .It "login-retries number 10 The number of login attempts
257 allowed before the login fails.
258 .It "passwd_format string md5 The encryption format that new or
259 changed passwords will use.
260 Valid values include "des", "md5" and "blf".
263 NIS server should probably use "des".
264 .It "passwd_prompt string The password prompt presented by
266 .It "times.allow list List of time periods during which
268 .It "times.deny list List of time periods during which logins are
270 .It "ttys.allow list List of ttys and ttygroups which users
271 in the class may use for access.
272 .It "ttys.deny list List of ttys and ttygroups which users
273 in the class may not use for access.
274 .It "warnexpire time Advance notice for pending account expiry.
275 .It "warnpassword time Advance notice for pending password expiry.
276 .\".It "widepasswords bool false Use the wide password format. The wide password
277 .\" format allows up to 128 significant characters in the password.
280 These fields are intended to be used by
282 and other programs in the login authentication system.
284 Capabilities that set environment variables are scanned for both
288 characters, which are substituted for a user's home directory and name
290 To pass these characters literally into the environment variable, escape
291 the character by preceding it with a backslash '\\'.
297 entries are comma separated lists used for checking remote access to the system,
298 and consist of a list of hostnames and/or IP addresses against which remote
299 network logins are checked.
300 Items in these lists may contain wildcards in the form used by shell programs
301 for wildcard matching (See
303 for details on the implementation).
304 The check on hosts is made against both the remote system's Internet address
305 and hostname (if available).
306 If both lists are empty or not specified, then logins from any remote host
308 If host.allow contains one or more hosts, then only remote systems matching
309 any of the items in that list are allowed to log in.
310 If host.deny contains one or more hosts, then a login from any matching hosts
317 entries consist of a comma-separated list of time periods during which the users
318 in a class are allowed to be logged in.
319 These are expressed as one or more day codes followed by a start and end times
320 expressed in 24 hour format, separated by a hyphen or dash.
321 For example, MoThSa0200-1300 translates to Monday, Thursday and Saturday between
322 the hours of 2 am and 1 p.m..
323 If both of these time lists are empty, users in the class are allowed access at
327 is specified, then logins are only allowed during the periods given.
330 is specified, then logins are denied during the periods given, regardless of whether
331 one of the periods specified in
337 enforces only that the actual login falls within periods allowed by these entries.
338 Further enforcement over the life of a session requires a separate daemon to
339 monitor transitions from an allowed period to a non-allowed one.
345 entries contain a comma-separated list of tty devices (without the /dev/ prefix)
346 that a user in a class may use to access the system, and/or a list of ttygroups
351 for information on ttygroups).
352 If neither entry exists, then the choice of login device used by the user is
356 is specified, then the user is restricted only to ttys in the given
357 group or device list.
360 is specified, then the user is prevented from using the specified devices or
361 devices in the group.
362 If both lists are given and are non-empty, the user is restricted to those
363 devices allowed by ttys.allow that are not available by ttys.deny.
369 facilities for enforcing restrictions on password quality, which used
372 have been superseded by the
375 .Sh RESERVED CAPABILITIES
376 The following capabilities are reserved for the purposes indicated and
377 may be supported by third-party software.
378 They are not implemented in the base system.
379 .Bl -column host.accounted indent indent
380 .It Sy "Name Type Notes Description
381 .It "accounted bool false Enable session time accounting for all users
383 .It "auth list passwd Allowed authentication styles.
384 The first item is the default style.
385 .It "auth-" Ns Ar type Ta "list Allowed authentication styles for the
388 .It "autodelete time Time after expiry when account is auto-deleted.
389 .It "bootfull bool false Enable 'boot only if ttygroup is full' strategy
390 when terminating sessions.
391 .It "daytime time Maximum login time per day.
392 .It "expireperiod time Time for expiry allocation.
393 .It "graceexpire time Grace days for expired account.
394 .It "gracetime time Additional grace login time allowed.
395 .It "host.accounted list List of remote host wildcards from which
396 login sessions will be accounted.
397 .It "host.exempt list List of remote host wildcards from which
398 login session accounting is exempted.
399 .It "idletime time Maximum idle time before logout.
400 .It "minpasswordlen number 6 The minimum length a local
402 .It "mixpasswordcase bool true Whether
404 will warn the user if an all lower case password is entered.
405 .It "monthtime time Maximum login time per month.
406 .It "passwordtime time Used by
408 to set next password expiry date.
409 .It "refreshtime time New time allowed on account refresh.
410 .It "refreshperiod str How often account time is refreshed.
411 .It "sessiontime time Maximum login time per session.
412 .It "sessionlimit number Maximum number of concurrent
413 login sessions on ttys in any group.
414 .It "ttys.accounted list List of ttys and ttygroups for which
415 login accounting is active.
416 .It "ttys.exempt list List of ttys and ttygroups for which login accounting
418 .It "warntime time Advance notice for pending out-of-time.
419 .It "weektime time Maximum login time per week.
426 fields operate in a similar manner to
projects / FreeBSD / releng / 7.2.git / blob