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: head/lib/libutil/login.conf.5 257205 2013-10-27 04:59:18Z eadler $ 21.\" 22.Dd January 21, 2012 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 53Users may individually create a file called 54.Pa .login_conf 55in their home directory using the same format, consisting of a single 56entry with a record id of "me". 57If present, this file is used by 58.Xr login 1 59to set user-defined environment settings which override those specified 60in the system login capabilities database. 61Only a subset of login capabilities may be overridden, typically those 62which do not involve authentication, resource limits and accounting. 63.Pp 64Records in a class capabilities database consist of a number of 65colon-separated fields. 66The first entry for each record gives one or more names that a record is 67to be known by, each separated by a '|' character. 68The first name is the most common abbreviation. 69The last name given should be a long name that is more descriptive 70of the capability entry, and all others are synonyms. 71All names but the last should be in lower case and contain no blanks; 72the last name may contain upper case characters and blanks for 73readability. 74.Pp 75Note that since a colon 76.Pq Ql :\& 77is used to separate capability entries, a 78.Ql \ec 79escape sequence must be used to embed a literal colon in the 80value or name of a capability. 81.Pp 82The default 83.Pa /etc/login.conf 84shipped with 85.Fx 86is an out of the box configuration. 87Whenever changes to this, or 88the user's 89.Pa ~/.login_conf , 90file are made, the modifications will not be picked up until 91.Xr cap_mkdb 1 92is used to compile the file into a database. 93This database file will have a 94.Pa .db 95extension and is accessed through 96.Xr cgetent 3 . 97See 98.Xr getcap 3 99for a more in-depth description of the format of a capability database. 100.Sh CAPABILITIES 101Fields within each record in the database follow the 102.Xr getcap 3 103conventions for boolean, type string 104.Ql \&= 105and type numeric 106.Ql \&# , 107although type numeric is deprecated in favour of the string format and 108either form is accepted for a numeric datum. 109Values fall into the following categories: 110.Bl -tag -width "program" 111.It bool 112If the name is present, then the boolean value is true; otherwise, it is 113false 114.It file 115Path name to a data file 116.It program 117Path name to an executable file 118.It list 119A list of values (or pairs of values) separated by commas or spaces 120.It path 121A space or comma separated list of path names, following the usual csh 122conventions (leading tilde with and without username being expanded to 123home directories etc.) 124.It number 125A numeric value, either decimal (default), hexadecimal (with leading 0x), 126or octal (with a leading 0). 127With a numeric type, only one numeric value is allowed. 128Numeric types may also be specified in string format (i.e., the capability 129tag being delimited from the value by '=' instead of '#'). 130Whichever method is used, then all records in the database must use the 131same method to allow values to be correctly overridden in interpolated 132records. 133A numeric value may be infinite. 134.It size 135A number which expresses a size. 136The default interpretation of a value is the number of bytes, but a 137suffix may specify alternate units: 138.Bl -tag -offset indent -compact -width xxxx 139.It b 140explicitly selects 512-byte blocks 141.It k 142selects kilobytes (1024 bytes) 143.It m 144specifies a multiplier of 1 megabyte (1048576 bytes), 145.It g 146specifies units of gigabytes, and 147.It t 148represents terabytes. 149.El 150A size value is a numeric quantity and case of the suffix is not significant. 151Concatenated values are added together. 152A size value may be infinite. 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. 173A time value may be infinite. 174.El 175.Pp 176.Dq infinity , 177.Dq inf , 178.Dq unlimited , 179.Dq unlimit , 180and -1 181are considered infinite values. 182.Pp 183The usual convention to interpolate capability entries using the special 184.Em tc=value 185notation may be used. 186.Sh RESOURCE LIMITS 187.Bl -column coredumpsize indent indent 188.It Sy "Name Type Notes Description" 189.It "coredumpsize size Maximum coredump size limit." 190.It "cputime time CPU usage limit." 191.It "datasize size Maximum data size limit." 192.It "filesize size Maximum file size limit." 193.It "maxproc number Maximum number of processes." 194.It "memorylocked size Maximum locked in core memory size limit." 195.It "memoryuse size Maximum of core memory use size limit." 196.It "openfiles number Maximum number of open files per process." 197.It "sbsize size Maximum permitted socketbuffer size." 198.It "vmemoryuse size Maximum permitted total VM usage per process." 199.It "stacksize size Maximum stack size limit." 200.It "posixlocks size Maximum number of POSIX-type advisory-mode locks." 201.El 202.Pp 203These resource limit entries actually specify both the maximum 204and current limits (see 205.Xr getrlimit 2 ) . 206The current (soft) limit is the one normally used, although the user is 207permitted to increase the current limit to the maximum (hard) limit. 208The maximum and current limits may be specified individually by appending a 209-max or -cur to the capability name. 210.Sh ENVIRONMENT 211.Bl -column ignorenologin indent xbinxxusrxbin 212.It Sy "Name Type Notes Description" 213.It "charset string Set $MM_CHARSET environment variable to the specified" 214value. 215.It "hushlogin bool false Same as having a ~/.hushlogin file." 216.It "ignorenologin bool false Login not prevented by nologin." 217.It "lang string Set $LANG environment variable to the specified value." 218.It "manpath path Default search path for manpages." 219.It "nocheckmail bool false Display mail status at login." 220.It "nologin file If the file exists it will be displayed and" 221the login session will be terminated. 222.It "path path /bin /usr/bin Default search path." 223.It "priority number Initial priority (nice) level." 224.It "requirehome bool false Require a valid home directory to login." 225.It "setenv list A comma-separated list of environment variables and" 226values to which they are to be set. 227.It "shell prog Session shell to execute rather than the" 228shell specified in the passwd file. 229The SHELL environment variable will 230contain the shell specified in the password file. 231.It "term string Default terminal type if not able to determine" 232from other means. 233.It "timezone string Default value of $TZ environment variable." 234.It "umask number 022 Initial umask. Should always have a leading 0 to" 235ensure octal interpretation. 236.It "welcome file /etc/motd File containing welcome message." 237.El 238.Sh AUTHENTICATION 239.Bl -column minpasswordlen indent indent 240.It Sy "Name Type Notes Description" 241.\" .It "approve program Program to approve login. 242.It "copyright file File containing additional copyright information" 243.It "host.allow list List of remote host wildcards from which users in" 244the class may access. 245.It "host.deny list List of remote host wildcards from which users" 246in the class may not access. 247.It "login_prompt string The login prompt given by" 248.Xr login 1 249.It "minpasswordlen number 6 The minimum length a local password may be." 250.It "mixpasswordcase bool true Whether" 251.Xr passwd 1 252will warn the user if an all lower case password is entered. 253.It "login-backoff number 3 The number of login attempts" 254allowed before the backoff delay is inserted after each subsequent 255attempt. 256.It "login-retries number 10 The number of login attempts" 257allowed before the login fails. 258.It "passwd_format string sha512 The encryption format that new or" 259changed passwords will use. 260Valid values include "des", "md5", "blf", "sha256" and "sha512"; see 261.Xr crypt 3 262for details. 263NIS clients using a 264.No non- Ns Dx Ns / Ns Fx 265NIS server should probably use "des". 266.It "passwd_prompt string The password prompt presented by" 267.Xr login 1 268.It "times.allow list List of time periods during which" 269logins are allowed. 270.It "times.deny list List of time periods during which logins are" 271disallowed. 272.It "ttys.allow list List of ttys and ttygroups which users" 273in the class may use for access. 274.It "ttys.deny list List of ttys and ttygroups which users" 275in the class may not use for access. 276.\".It "widepasswords bool false Use the wide password format. The wide password 277.\" format allows up to 128 significant characters in the password. 278.El 279.Pp 280These fields are intended to be used by 281.Xr passwd 1 282and other programs in the login authentication system. 283.Pp 284Capabilities that set environment variables are scanned for both 285.Ql \&~ 286and 287.Ql \&$ 288characters, which are substituted for a user's home directory and name 289respectively. 290To pass these characters literally into the environment variable, escape 291the character by preceding it with a backslash '\\'. 292.Pp 293The 294.Em host.allow 295and 296.Em host.deny 297entries are comma separated lists used for checking remote access to the system, 298and consist of a list of hostnames and/or IP addresses against which remote 299network logins are checked. 300Items in these lists may contain wildcards in the form used by shell programs 301for wildcard matching (See 302.Xr fnmatch 3 303for details on the implementation). 304The check on hosts is made against both the remote system's Internet address 305and hostname (if available). 306If both lists are empty or not specified, then logins from any remote host 307are allowed. 308If host.allow contains one or more hosts, then only remote systems matching 309any of the items in that list are allowed to log in. 310If host.deny contains one or more hosts, then a login from any matching hosts 311will be disallowed. 312.Pp 313The 314.Em times.allow 315and 316.Em times.deny 317entries consist of a comma-separated list of time periods during which the users 318in a class are allowed to be logged in. 319These are expressed as one or more day codes followed by a start and end times 320expressed in 24 hour format, separated by a hyphen or dash. 321For example, MoThSa0200-1300 translates to Monday, Thursday and Saturday between 322the hours of 2 am and 1 p.m.. 323If both of these time lists are empty, users in the class are allowed access at 324any time. 325If 326.Em times.allow 327is specified, then logins are only allowed during the periods given. 328If 329.Em times.deny 330is specified, then logins are denied during the periods given, regardless of whether 331one of the periods specified in 332.Em times.allow 333applies. 334.Pp 335Note that 336.Xr login 1 337enforces only that the actual login falls within periods allowed by these entries. 338Further enforcement over the life of a session requires a separate daemon to 339monitor transitions from an allowed period to a non-allowed one. 340.Pp 341The 342.Em ttys.allow 343and 344.Em ttys.deny 345entries contain a comma-separated list of tty devices (without the /dev/ prefix) 346that a user in a class may use to access the system, and/or a list of ttygroups 347(See 348.Xr getttyent 3 349and 350.Xr ttys 5 351for information on ttygroups). 352If neither entry exists, then the choice of login device used by the user is 353unrestricted. 354If only 355.Em ttys.allow 356is specified, then the user is restricted only to ttys in the given 357group or device list. 358If only 359.Em ttys.deny 360is specified, then the user is prevented from using the specified devices or 361devices in the group. 362If both lists are given and are non-empty, the user is restricted to those 363devices allowed by ttys.allow that are not available by ttys.deny. 364.Sh ACCOUNTING LIMITS 365.Bl -column host.accounted indent indent 366.It Sy "Name Type Notes Description" 367.It "accounted bool false Enable session time accounting for all users" 368in this class. 369.It "autodelete time Time after expiry when account is auto-deleted." 370.It "bootfull bool false Enable 'boot only if ttygroup is full' strategy" 371when terminating sessions. 372.It "daytime time Maximum login time per day." 373.It "expireperiod time Time for expiry allocation." 374.It "graceexpire time Grace days for expired account." 375.It "gracetime time Additional grace login time allowed." 376.It "host.accounted list List of remote host wildcards from which" 377login sessions will be accounted. 378.It "host.exempt list List of remote host wildcards from which" 379login session accounting is exempted. 380.It "idletime time Maximum idle time before logout (unused)." 381.It "monthtime time Maximum login time per month." 382.It "passwordtime time Used by" 383.Xr passwd 1 384to set next password expiry date. 385.It "refreshtime time New time allowed on account refresh." 386.It "refreshperiod str How often account time is refreshed." 387.It "sessiontime time Maximum login time per session." 388.It "sessionlimit number Maximum number of concurrent" 389login sessions on ttys in any group. 390.It "ttys.accounted list List of ttys and ttygroups for which" 391login accounting is active. 392.It "ttys.exempt list List of ttys and ttygroups for which login accounting" 393is exempt. 394.It "warnexpire time Advance notice for pending account expiry." 395.It "warnpassword time Advance notice for pending password expiry." 396.It "warntime time Advance notice for pending out-of-time." 397.It "weektime time Maximum login time per week." 398.El 399.Pp 400These fields are used by the time accounting system, which regulates, 401controls and records user login access. 402.Pp 403The 404.Em ttys.accounted 405and 406.Em ttys.exempt 407fields operate in a similar manner to 408.Em ttys.allow 409and 410.Em ttys.deny 411as explained 412above. 413Similarly with the 414.Em host.accounted 415and 416.Em host.exempt 417lists. 418.Sh SEE ALSO 419.Xr cap_mkdb 1 , 420.Xr login 1 , 421.Xr crypt 3 , 422.Xr getcap 3 , 423.Xr getttyent 3 , 424.Xr login_cap 3 , 425.Xr login_class 3 , 426.Xr passwd 5 , 427.Xr ttys 5 428.Sh BUGS 429The 430.Em idletime 431setting is not enforced. 432