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.Dd June 28, 2023 21.Dt LOGIN.CONF 5 22.Os 23.Sh NAME 24.Nm login.conf 25.Nd login class capability database 26.Sh SYNOPSIS 27.Pa /etc/login.conf , 28.Pa ~/.login_conf 29.Sh DESCRIPTION 30.Nm 31contains various attributes and capabilities of login classes. 32A login class (an optional annotation against each record in the user 33account database, 34.Pa /etc/master.passwd ) 35determines session accounting, resource limits and user environment settings. 36It is used by various programs in the system to set up a user's login 37environment and to enforce policy, accounting and administrative restrictions. 38It also provides the means by which users are able to be 39authenticated to the system and the types of authentication available. 40Attributes in addition to the ones described here are available with 41third-party packages. 42.Pp 43A special record "default" in the system user class capability database 44.Pa /etc/login.conf 45is used automatically for any 46non-root user without a valid login class in 47.Pa /etc/master.passwd . 48A user with a uid of 0 without a valid login class will use the record 49"root" if it exists, or "default" if not. 50.Pp 51Users may individually create a file called 52.Pa .login_conf 53in their home directory using the same format, consisting of a single 54entry with a record id of "me". 55If present, this file is used by 56.Xr login 1 57to set user-defined environment settings which override those specified 58in the system login capabilities database. 59Only a subset of login capabilities may be overridden, typically those 60which do not involve authentication, resource limits and accounting. 61.Pp 62Records in a class capabilities database consist of a number of 63colon-separated fields. 64The first entry for each record gives one or more names that a record is 65to be known by, each separated by a '|' character. 66The first name is the most common abbreviation. 67The last name given should be a long name that is more descriptive 68of the capability entry, and all others are synonyms. 69All names but the last should be in lower case and contain no blanks; 70the last name may contain upper case characters and blanks for 71readability. 72.Pp 73Note that since a colon 74.Pq Ql :\& 75is used to separate capability entries, a 76.Ql \ec 77escape sequence must be used to embed a literal colon in the 78value or name of a capability. 79.Pp 80The default 81.Pa /etc/login.conf 82shipped with 83.Fx 84is an out of the box configuration. 85Whenever changes to this, or 86the user's 87.Pa ~/.login_conf , 88file are made, the modifications will not be picked up until 89.Xr cap_mkdb 1 90is used to compile the file into a database. 91This database file will have a 92.Pa .db 93extension and is accessed through 94.Xr cgetent 3 . 95See 96.Xr getcap 3 97for a more in-depth description of the format of a capability database. 98.Sh CAPABILITIES 99Fields within each record in the database follow the 100.Xr getcap 3 101conventions for boolean, type string 102.Ql \&= 103and type numeric 104.Ql \&# , 105although type numeric is deprecated in favour of the string format and 106either form is accepted for a numeric datum. 107Values fall into the following categories: 108.Bl -tag -width "program" 109.It bool 110If the name is present, then the boolean value is true; otherwise, it is 111false 112.It file 113Path name to a data file 114.It program 115Path name to an executable file 116.It list 117A list of values (or pairs of values) separated by commas or spaces 118.It path 119A space or comma separated list of path names, following the usual csh 120conventions (leading tilde with and without username being expanded to 121home directories etc.) 122.It number 123A numeric value, either decimal (default), hexadecimal (with leading 0x), 124or octal (with a leading 0). 125With a numeric type, only one numeric value is allowed. 126Numeric types may also be specified in string format (i.e., the capability 127tag being delimited from the value by '=' instead of '#'). 128Whichever method is used, then all records in the database must use the 129same method to allow values to be correctly overridden in interpolated 130records. 131A numeric value may be infinite. 132.It size 133A number which expresses a size. 134The default interpretation of a value is the number of bytes, but a 135suffix may specify alternate units: 136.Bl -tag -offset indent -compact -width xxxx 137.It b 138explicitly selects 512-byte blocks 139.It k 140selects kilobytes (1024 bytes) 141.It m 142specifies a multiplier of 1 megabyte (1048576 bytes), 143.It g 144specifies units of gigabytes, and 145.It t 146represents terabytes. 147.El 148A size value is a numeric quantity and case of the suffix is not significant. 149Concatenated values are added together. 150A size value may be infinite. 151.It time 152A period of time, by default in seconds. 153A prefix may specify a different unit: 154.Bl -tag -offset indent -compact -width xxxx 155.It y 156indicates the number of 365 day years, 157.It w 158indicates the number of weeks, 159.It d 160the number of days, 161.It h 162the number of hours, 163.It m 164the number of minutes, and 165.It s 166the number of seconds. 167.El 168Concatenated values are added together. 169For example, 2 hours and 40 minutes may be written either as 1709600s, 160m or 2h40m. 171A time value may be infinite. 172.El 173.Pp 174.Dq infinity , 175.Dq inf , 176.Dq unlimited , 177.Dq unlimit, 178and -1 179are considered infinite values. 180.Pp 181The usual convention to interpolate capability entries using the special 182.Em tc=value 183notation may be used. 184.Sh RESOURCE LIMITS 185.Bl -column pseudoterminals indent indent 186.It Sy "Name Type Notes Description" 187.It "coredumpsize size Maximum coredump size limit." 188.It "cputime time CPU usage limit." 189.It "datasize size Maximum data size limit." 190.It "filesize size Maximum file size limit." 191.It "maxproc number Maximum number of processes." 192.It "memorylocked size Maximum locked in core memory size limit." 193.It "memoryuse size Maximum of core memory use size limit." 194.It "openfiles number Maximum number of open files per process." 195.It "sbsize size Maximum permitted socketbuffer size." 196.It "vmemoryuse size Maximum permitted total VM usage per process." 197.It "stacksize size Maximum stack size limit." 198.It "pseudoterminals number Maximum number of pseudo-terminals." 199.It "swapuse size Maximum swap space size limit." 200.It "umtxp number Maximum number of process-shared pthread 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 "cpumask string List of cpus to bind the user to." 216The syntax is the same as for the 217.Fl l 218argument of 219.Xr cpuset 1 220or the word 221.Ql default . 222If set to 223.Ql default 224no action is taken. 225.It "hushlogin bool false Same as having a ~/.hushlogin file." 226.It "ignorenologin bool false Login not prevented by nologin." 227.It "ftp-chroot bool false Limit FTP access with" 228.Xr chroot 2 229to the 230.Ev HOME 231directory of the user. 232See 233.Xr ftpd 8 234for details. 235.It "label string Default MAC policy; see" 236.Xr maclabel 7 . 237.It "lang string Set $LANG environment variable to the specified value." 238.It "mail string Set $MAIL environment variable to the specified value." 239.It "manpath path Default search path for manpages." 240.It "nocheckmail bool false Display mail status at login." 241.It "nologin file If the file exists it will be displayed and" 242the login session will be terminated. 243.It "path path /bin /usr/bin Default search path." 244.It "priority number Initial priority (nice) level." 245.It "requirehome bool false Require a valid home directory to login." 246.It "setenv list A comma-separated list of environment variables and" 247values to which they are to be set. 248Values containing commas must be quoted. 249.It "shell prog Session shell to execute rather than the" 250shell specified in the passwd file. 251The SHELL environment variable will 252contain the shell specified in the password file. 253.It "term string Default terminal type if not able to determine" 254from other means. 255.It "timezone string Default value of $TZ environment variable." 256.It "umask number 022 Initial umask. Should always have a leading 0 to" 257ensure octal interpretation. 258.It "welcome file /etc/motd File containing welcome message." 259.El 260.Sh AUTHENTICATION 261.Bl -column passwd_prompt indent indent 262.It Sy "Name Type Notes Description" 263.\" .It "approve program Program to approve login. 264.It "copyright file File containing additional copyright information" 265.It "host.allow list List of remote host wildcards from which users in" 266the class may access. 267.It "host.deny list List of remote host wildcards from which users" 268in the class may not access. 269.It "login_prompt string The login prompt given by" 270.Xr login 1 271.It "login-backoff number 3 The number of login attempts" 272allowed before the backoff delay is inserted after each subsequent 273attempt. 274The backoff delay is the number of tries above 275.Em login-backoff 276multiplied by 5 seconds. 277.It "login-retries number 10 The number of login attempts" 278allowed before the login fails. 279.It "passwd_format string sha512 The encryption format that new or" 280changed passwords will use. 281Valid values include "des", "md5", "blf", "sha256" and "sha512"; see 282.Xr crypt 3 283for details. 284NIS clients using a 285.No non- Ns Fx 286NIS server should probably use "des". 287.It "passwd_prompt string The password prompt presented by" 288.Xr login 1 289.It "passwordtime time Used by" 290.Xr passwd 1 291to set next password expiry date. 292.It "times.allow list List of time periods during which" 293logins are allowed. 294.It "times.deny list List of time periods during which logins are" 295disallowed. 296.It "ttys.allow list List of ttys and ttygroups which users" 297in the class may use for access. 298.It "ttys.deny list List of ttys and ttygroups which users" 299in the class may not use for access. 300.It "warnexpire time Advance notice for pending account expiry." 301.It "warnpassword time Advance notice for pending password expiry." 302.\".It "widepasswords bool false Use the wide password format. The wide password 303.\" format allows up to 128 significant characters in the password. 304.El 305.Pp 306These fields are intended to be used by 307.Xr passwd 1 308and other programs in the login authentication system. 309.Pp 310Capabilities that set environment variables are scanned for both 311.Ql \&~ 312and 313.Ql \&$ 314characters, which are substituted for a user's home directory and name 315respectively. 316To pass these characters literally into the environment variable, escape 317the character by preceding it with a backslash '\\'. 318.Pp 319The 320.Em host.allow 321and 322.Em host.deny 323entries are comma separated lists used for checking remote access to the system, 324and consist of a list of hostnames and/or IP addresses against which remote 325network logins are checked. 326Items in these lists may contain wildcards in the form used by shell programs 327for wildcard matching (See 328.Xr fnmatch 3 329for details on the implementation). 330The check on hosts is made against both the remote system's Internet address 331and hostname (if available). 332If both lists are empty or not specified, then logins from any remote host 333are allowed. 334If host.allow contains one or more hosts, then only remote systems matching 335any of the items in that list are allowed to log in. 336If host.deny contains one or more hosts, then a login from any matching hosts 337will be disallowed. 338.Pp 339The 340.Em times.allow 341and 342.Em times.deny 343entries consist of a comma-separated list of time periods during which the users 344in a class are allowed to be logged in. 345These are expressed as one or more day codes followed by a start and end times 346expressed in 24 hour format, separated by a hyphen or dash. 347For example, MoThSa0200-1300 translates to Monday, Thursday and Saturday between 348the hours of 2 am and 1 p.m.. 349If both of these time lists are empty, users in the class are allowed access at 350any time. 351If 352.Em times.allow 353is specified, then logins are only allowed during the periods given. 354If 355.Em times.deny 356is specified, then logins are denied during the periods given, regardless of whether 357one of the periods specified in 358.Em times.allow 359applies. 360.Pp 361Note that 362.Xr login 1 363enforces only that the actual login falls within periods allowed by these entries. 364Further enforcement over the life of a session requires a separate daemon to 365monitor transitions from an allowed period to a non-allowed one. 366.Pp 367The 368.Em ttys.allow 369and 370.Em ttys.deny 371entries contain a comma-separated list of tty devices (without the /dev/ prefix) 372that a user in a class may use to access the system, and/or a list of ttygroups 373(See 374.Xr getttyent 3 375and 376.Xr ttys 5 377for information on ttygroups). 378If neither entry exists, then the choice of login device used by the user is 379unrestricted. 380If only 381.Em ttys.allow 382is specified, then the user is restricted only to ttys in the given 383group or device list. 384If only 385.Em ttys.deny 386is specified, then the user is prevented from using the specified devices or 387devices in the group. 388If both lists are given and are non-empty, the user is restricted to those 389devices allowed by ttys.allow that are not available by ttys.deny. 390.Pp 391The 392.Em minpasswordlen 393and 394.Em minpasswordcase 395facilities for enforcing restrictions on password quality, which used 396to be supported by 397.Nm , 398have been superseded by the 399.Xr pam_passwdqc 8 400PAM module. 401.Sh RESERVED CAPABILITIES 402The following capabilities are reserved for the purposes indicated and 403may be supported by third-party software. 404They are not implemented in the base system. 405.Bl -column host.accounted indent indent 406.It Sy "Name Type Notes Description" 407.It "accounted bool false Enable session time accounting for all users" 408in this class. 409.It "auth list passwd Allowed authentication styles." 410The first item is the default style. 411.It "auth-" Ns Ar type Ta "list Allowed authentication styles for the" 412authentication 413.Ar type . 414.It "autodelete time Time after expiry when account is auto-deleted." 415.It "bootfull bool false Enable 'boot only if ttygroup is full' strategy" 416when terminating sessions. 417.It "daytime time Maximum login time per day." 418.It "expireperiod time Time for expiry allocation." 419.It "graceexpire time Grace days for expired account." 420.It "gracetime time Additional grace login time allowed." 421.It "host.accounted list List of remote host wildcards from which" 422login sessions will be accounted. 423.It "host.exempt list List of remote host wildcards from which" 424login session accounting is exempted. 425.It "idletime time Maximum idle time before logout." 426.It "minpasswordlen number 6 The minimum length a local" 427password may be. 428.It "mixpasswordcase bool true Whether" 429.Xr passwd 1 430will warn the user if an all lower case password is entered. 431.It "monthtime time Maximum login time per month." 432.It "refreshtime time New time allowed on account refresh." 433.It "refreshperiod str How often account time is refreshed." 434.It "sessiontime time Maximum login time per session." 435.It "sessionlimit number Maximum number of concurrent" 436login sessions on ttys in any group. 437.It "ttys.accounted list List of ttys and ttygroups for which" 438login accounting is active. 439.It "ttys.exempt list List of ttys and ttygroups for which login accounting" 440is exempt. 441.It "warntime time Advance notice for pending out-of-time." 442.It "weektime time Maximum login time per week." 443.El 444.Pp 445The 446.Em ttys.accounted 447and 448.Em ttys.exempt 449fields operate in a similar manner to 450.Em ttys.allow 451and 452.Em ttys.deny 453as explained 454above. 455Similarly with the 456.Em host.accounted 457and 458.Em host.exempt 459lists. 460.Sh SEE ALSO 461.Xr cap_mkdb 1 , 462.Xr login 1 , 463.Xr chroot 2 , 464.Xr getcap 3 , 465.Xr getttyent 3 , 466.Xr login_cap 3 , 467.Xr login_class 3 , 468.Xr pam 3 , 469.Xr passwd 5 , 470.Xr ttys 5 , 471.Xr ftpd 8 , 472.Xr pam_passwdqc 8 473.Sh HISTORY 474The file 475.Nm 476first appeared in 477.Fx 2.1.5 . 478