1.\" Copyright (c) 1996 David Nugent <davidn@blaze.net.au>
2.\" All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, is permitted provided that the following conditions
6.\" are met:
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
16.\" David Nugent.
17.\" 5. Modifications may be freely made to this file providing the above
18.\" conditions are met.
19.\"
|
20.\" $FreeBSD: stable/9/lib/libutil/login.conf.5 235586 2012-05-18 01:51:12Z gjb $
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| 20.\" $FreeBSD: stable/9/lib/libutil/login.conf.5 238481 2012-07-15 11:39:35Z des $ |
21.\"
22.Dd July 8, 2011
23.Dt LOGIN.CONF 5
24.Os
25.Sh NAME
26.Nm login.conf
27.Nd login class capability database
28.Sh SYNOPSIS
29.Pa /etc/login.conf ,
30.Pa ~/.login_conf
31.Sh DESCRIPTION
32.Nm
33contains various attributes and capabilities of login classes.
34A login class (an optional annotation against each record in the user
35account database,
36.Pa /etc/master.passwd )
37determines session accounting, resource limits and user environment settings.
38It is used by various programs in the system to set up a user's login
39environment and to enforce policy, accounting and administrative restrictions.
40It also provides the means by which users are able to be
41authenticated to the system and the types of authentication available.
42Attributes in addition to the ones described here are available with
43third-party packages.
44.Pp
45A special record "default" in the system user class capability database
46.Pa /etc/login.conf
47is used automatically for any
48non-root user without a valid login class in
49.Pa /etc/master.passwd .
50A user with a uid of 0 without a valid login class will use the record
51"root" if it exists, or "default" if not.
52.Pp
53In
54.Fx ,
55users may individually create a file called
56.Pa .login_conf
57in their home directory using the same format, consisting of a single
58entry with a record id of "me".
59If present, this file is used by
60.Xr login 1
61to set user-defined environment settings which override those specified
62in the system login capabilities database.
63Only a subset of login capabilities may be overridden, typically those
64which do not involve authentication, resource limits and accounting.
65.Pp
66Records in a class capabilities database consist of a number of
67colon-separated fields.
68The first entry for each record gives one or more names that a record is
69to be known by, each separated by a '|' character.
70The first name is the most common abbreviation.
71The last name given should be a long name that is more descriptive
72of the capability entry, and all others are synonyms.
73All names but the last should be in lower case and contain no blanks;
74the last name may contain upper case characters and blanks for
75readability.
76.Pp
77Note that since a colon
78.Pq Ql :\&
79is used to separate capability entries, a
80.Ql \ec
81escape sequence must be used to embed a literal colon in the
82value or name of a capability.
83.Pp
84The default
85.Pa /etc/login.conf
86shipped with
87.Fx
88is an out of the box configuration.
89Whenever changes to this, or
90the user's
91.Pa ~/.login_conf ,
92file are made, the modifications will not be picked up until
93.Xr cap_mkdb 1
94is used to compile the file into a database.
95This database file will have a
96.Pa .db
97extension and is accessed through
98.Xr cgetent 3 .
99See
100.Xr getcap 3
101for a more in-depth description of the format of a capability database.
102.Sh CAPABILITIES
103Fields within each record in the database follow the
104.Xr getcap 3
105conventions for boolean, type string
106.Ql \&=
107and type numeric
108.Ql \&# ,
109although type numeric is deprecated in favour of the string format and
110either form is accepted for a numeric datum.
111Values fall into the following categories:
112.Bl -tag -width "program"
113.It bool
114If the name is present, then the boolean value is true; otherwise, it is
115false
116.It file
117Path name to a data file
118.It program
119Path name to an executable file
120.It list
121A list of values (or pairs of values) separated by commas or spaces
122.It path
123A space or comma separated list of path names, following the usual csh
124conventions (leading tilde with and without username being expanded to
125home directories etc.)
126.It number
127A numeric value, either decimal (default), hexadecimal (with leading 0x),
128or octal (with a leading 0).
129With a numeric type, only one numeric value is allowed.
130Numeric types may also be specified in string format (i.e., the capability
131tag being delimited from the value by '=' instead of '#').
132Whichever method is used, then all records in the database must use the
133same method to allow values to be correctly overridden in interpolated
134records.
135.It size
136A number which expresses a size.
137The default interpretation of a value is the number of bytes, but a
138suffix may specify alternate units:
139.Bl -tag -offset indent -compact -width xxxx
140.It b
141explicitly selects 512-byte blocks
142.It k
143selects kilobytes (1024 bytes)
144.It m
145specifies a multiplier of 1 megabyte (1048576 bytes),
146.It g
147specifies units of gigabytes, and
148.It t
149represents terabytes.
150.El
151A size value is a numeric quantity and case of the suffix is not significant.
152Concatenated values are added together.
153.It time
154A period of time, by default in seconds.
155A prefix may specify a different unit:
156.Bl -tag -offset indent -compact -width xxxx
157.It y
158indicates the number of 365 day years,
159.It w
160indicates the number of weeks,
161.It d
162the number of days,
163.It h
164the number of hours,
165.It m
166the number of minutes, and
167.It s
168the number of seconds.
169.El
170Concatenated values are added together.
171For example, 2 hours and 40 minutes may be written either as
1729600s, 160m or 2h40m.
173.El
174.Pp
175The usual convention to interpolate capability entries using the special
176.Em tc=value
177notation may be used.
178.Sh RESOURCE LIMITS
179.Bl -column pseudoterminals 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.
192.It "pseudoterminals number Maximum number of pseudo-terminals.
193.It "swapuse size Maximum swap space size limit.
194.El
195.Pp
196These resource limit entries actually specify both the maximum
197and current limits (see
198.Xr getrlimit 2 ) .
199The current (soft) limit is the one normally used, although the user is
200permitted to increase the current limit to the maximum (hard) limit.
201The maximum and current limits may be specified individually by appending a
202-max or -cur to the capability name.
203.Sh ENVIRONMENT
204.Bl -column ignorenologin indent xbinxxusrxbin
205.It Sy "Name Type Notes Description
206.It "charset string Set $MM_CHARSET environment variable to the specified
207value.
208.It "cpumask string List of cpus to bind the user to.
209The syntax is the same as for the
210.Fl l
211argument of
212.Xr cpuset 1
213or the word
214.Ql default .
215If set to
216.Ql default
217no action is taken.
218.It "hushlogin bool false Same as having a ~/.hushlogin file.
219.It "ignorenologin bool false Login not prevented by nologin.
220.It "ftp-chroot bool false Limit FTP access with
221.Xr chroot 2
222to the
223.Ev HOME
224directory of the user.
225See
226.Xr ftpd 8
227for details.
228.It "label string Default MAC policy; see
229.Xr maclabel 7 .
230.It "lang string Set $LANG environment variable to the specified value.
231.It "manpath path Default search path for manpages.
232.It "nocheckmail bool false Display mail status at login.
233.It "nologin file If the file exists it will be displayed and
234the login session will be terminated.
235.It "path path /bin /usr/bin Default search path.
236.It "priority number Initial priority (nice) level.
237.It "requirehome bool false Require a valid home directory to login.
238.It "setenv list A comma-separated list of environment variables and
239values to which they are to be set.
240.It "shell prog Session shell to execute rather than the
241shell specified in the passwd file.
242The SHELL environment variable will
243contain the shell specified in the password file.
244.It "term string Default terminal type if not able to determine
245from other means.
246.It "timezone string Default value of $TZ environment variable.
247.It "umask number 022 Initial umask. Should always have a leading 0 to
248ensure octal interpretation.
249.It "welcome file /etc/motd File containing welcome message.
250.El
251.Sh AUTHENTICATION
252.Bl -column passwd_prompt indent indent
253.It Sy "Name Type Notes Description
254.\" .It "approve program Program to approve login.
255.It "copyright file File containing additional copyright information
256.It "host.allow list List of remote host wildcards from which users in
257the class may access.
258.It "host.deny list List of remote host wildcards from which users
259in the class may not access.
260.It "login_prompt string The login prompt given by
261.Xr login 1
262.It "login-backoff number 3 The number of login attempts
263allowed before the backoff delay is inserted after each subsequent
264attempt.
265The backoff delay is the number of tries above
266.Em login-backoff
267multiplied by 5 seconds.
268.It "login-retries number 10 The number of login attempts
269allowed before the login fails.
270.It "passwd_format string md5 The encryption format that new or
271changed passwords will use.
|
272Valid values include "des", "md5" and "blf".
|
272Valid values include "des", "md5", "blf", "sha256" and "sha512"; see
273.Xr crypt 3
274for details. |
275NIS clients using a
276.No non- Ns Fx
277NIS server should probably use "des".
278.It "passwd_prompt string The password prompt presented by
279.Xr login 1
280.It "times.allow list List of time periods during which
281logins are allowed.
282.It "times.deny list List of time periods during which logins are
283disallowed.
284.It "ttys.allow list List of ttys and ttygroups which users
285in the class may use for access.
286.It "ttys.deny list List of ttys and ttygroups which users
287in the class may not use for access.
288.It "warnexpire time Advance notice for pending account expiry.
289.It "warnpassword time Advance notice for pending password expiry.
290.\".It "widepasswords bool false Use the wide password format. The wide password
291.\" format allows up to 128 significant characters in the password.
292.El
293.Pp
294These fields are intended to be used by
295.Xr passwd 1
296and other programs in the login authentication system.
297.Pp
298Capabilities that set environment variables are scanned for both
299.Ql \&~
300and
301.Ql \&$
302characters, which are substituted for a user's home directory and name
303respectively.
304To pass these characters literally into the environment variable, escape
305the character by preceding it with a backslash '\\'.
306.Pp
307The
308.Em host.allow
309and
310.Em host.deny
311entries are comma separated lists used for checking remote access to the system,
312and consist of a list of hostnames and/or IP addresses against which remote
313network logins are checked.
314Items in these lists may contain wildcards in the form used by shell programs
315for wildcard matching (See
316.Xr fnmatch 3
317for details on the implementation).
318The check on hosts is made against both the remote system's Internet address
319and hostname (if available).
320If both lists are empty or not specified, then logins from any remote host
321are allowed.
322If host.allow contains one or more hosts, then only remote systems matching
323any of the items in that list are allowed to log in.
324If host.deny contains one or more hosts, then a login from any matching hosts
325will be disallowed.
326.Pp
327The
328.Em times.allow
329and
330.Em times.deny
331entries consist of a comma-separated list of time periods during which the users
332in a class are allowed to be logged in.
333These are expressed as one or more day codes followed by a start and end times
334expressed in 24 hour format, separated by a hyphen or dash.
335For example, MoThSa0200-1300 translates to Monday, Thursday and Saturday between
336the hours of 2 am and 1 p.m..
337If both of these time lists are empty, users in the class are allowed access at
338any time.
339If
340.Em times.allow
341is specified, then logins are only allowed during the periods given.
342If
343.Em times.deny
344is specified, then logins are denied during the periods given, regardless of whether
345one of the periods specified in
346.Em times.allow
347applies.
348.Pp
349Note that
350.Xr login 1
351enforces only that the actual login falls within periods allowed by these entries.
352Further enforcement over the life of a session requires a separate daemon to
353monitor transitions from an allowed period to a non-allowed one.
354.Pp
355The
356.Em ttys.allow
357and
358.Em ttys.deny
359entries contain a comma-separated list of tty devices (without the /dev/ prefix)
360that a user in a class may use to access the system, and/or a list of ttygroups
361(See
362.Xr getttyent 3
363and
364.Xr ttys 5
365for information on ttygroups).
366If neither entry exists, then the choice of login device used by the user is
367unrestricted.
368If only
369.Em ttys.allow
370is specified, then the user is restricted only to ttys in the given
371group or device list.
372If only
373.Em ttys.deny
374is specified, then the user is prevented from using the specified devices or
375devices in the group.
376If both lists are given and are non-empty, the user is restricted to those
377devices allowed by ttys.allow that are not available by ttys.deny.
378.Pp
379The
380.Em minpasswordlen
381and
382.Em minpasswordcase
383facilities for enforcing restrictions on password quality, which used
384to be supported by
385.Nm ,
386have been superseded by the
387.Xr pam_passwdqc 8
388PAM module.
389.Sh RESERVED CAPABILITIES
390The following capabilities are reserved for the purposes indicated and
391may be supported by third-party software.
392They are not implemented in the base system.
393.Bl -column host.accounted indent indent
394.It Sy "Name Type Notes Description
395.It "accounted bool false Enable session time accounting for all users
396in this class.
397.It "auth list passwd Allowed authentication styles.
398The first item is the default style.
399.It "auth-" Ns Ar type Ta "list Allowed authentication styles for the
400authentication
401.Ar type .
402.It "autodelete time Time after expiry when account is auto-deleted.
403.It "bootfull bool false Enable 'boot only if ttygroup is full' strategy
404when terminating sessions.
405.It "daytime time Maximum login time per day.
406.It "expireperiod time Time for expiry allocation.
407.It "graceexpire time Grace days for expired account.
408.It "gracetime time Additional grace login time allowed.
409.It "host.accounted list List of remote host wildcards from which
410login sessions will be accounted.
411.It "host.exempt list List of remote host wildcards from which
412login session accounting is exempted.
413.It "idletime time Maximum idle time before logout.
414.It "minpasswordlen number 6 The minimum length a local
415password may be.
416.It "mixpasswordcase bool true Whether
417.Xr passwd 1
418will warn the user if an all lower case password is entered.
419.It "monthtime time Maximum login time per month.
420.It "passwordtime time Used by
421.Xr passwd 1
422to set next password expiry date.
423.It "refreshtime time New time allowed on account refresh.
424.It "refreshperiod str How often account time is refreshed.
425.It "sessiontime time Maximum login time per session.
426.It "sessionlimit number Maximum number of concurrent
427login sessions on ttys in any group.
428.It "ttys.accounted list List of ttys and ttygroups for which
429login accounting is active.
430.It "ttys.exempt list List of ttys and ttygroups for which login accounting
431is exempt.
432.It "warntime time Advance notice for pending out-of-time.
433.It "weektime time Maximum login time per week.
434.El
435.Pp
436The
437.Em ttys.accounted
438and
439.Em ttys.exempt
440fields operate in a similar manner to
441.Em ttys.allow
442and
443.Em ttys.deny
444as explained
445above.
446Similarly with the
447.Em host.accounted
448and
449.Em host.exempt
450lists.
451.Sh SEE ALSO
452.Xr cap_mkdb 1 ,
453.Xr login 1 ,
454.Xr chroot 2 ,
455.Xr getcap 3 ,
456.Xr getttyent 3 ,
457.Xr login_cap 3 ,
458.Xr login_class 3 ,
459.Xr pam 3 ,
460.Xr passwd 5 ,
461.Xr ttys 5 ,
462.Xr ftpd 8 ,
463.Xr pam_passwdqc 8
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