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.\" $FreeBSD$ 21.\" 22.Dd June 28, 2023 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 pseudoterminals 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 "pseudoterminals number Maximum number of pseudo-terminals." 201.It "swapuse size Maximum swap space size limit." 202.It "umtxp number Maximum number of process-shared pthread locks." 203.El 204.Pp 205These resource limit entries actually specify both the maximum 206and current limits (see 207.Xr getrlimit 2 ) . 208The current (soft) limit is the one normally used, although the user is 209permitted to increase the current limit to the maximum (hard) limit. 210The maximum and current limits may be specified individually by appending a 211-max or -cur to the capability name. 212.Sh ENVIRONMENT 213.Bl -column ignorenologin indent xbinxxusrxbin 214.It Sy "Name Type Notes Description" 215.It "charset string Set $MM_CHARSET environment variable to the specified" 216value. 217.It "cpumask string List of cpus to bind the user to." 218The syntax is the same as for the 219.Fl l 220argument of 221.Xr cpuset 1 222or the word 223.Ql default . 224If set to 225.Ql default 226no action is taken. 227.It "hushlogin bool false Same as having a ~/.hushlogin file." 228.It "ignorenologin bool false Login not prevented by nologin." 229.It "ftp-chroot bool false Limit FTP access with" 230.Xr chroot 2 231to the 232.Ev HOME 233directory of the user. 234See 235.Xr ftpd 8 236for details. 237.It "label string Default MAC policy; see" 238.Xr maclabel 7 . 239.It "lang string Set $LANG environment variable to the specified value." 240.It "mail string Set $MAIL environment variable to the specified value." 241.It "manpath path Default search path for manpages." 242.It "nocheckmail bool false Display mail status at login." 243.It "nologin file If the file exists it will be displayed and" 244the login session will be terminated. 245.It "path path /bin /usr/bin Default search path." 246.It "priority number Initial priority (nice) level." 247.It "requirehome bool false Require a valid home directory to login." 248.It "setenv list A comma-separated list of environment variables and" 249values to which they are to be set. 250Values containing commas must be quoted. 251.It "shell prog Session shell to execute rather than the" 252shell specified in the passwd file. 253The SHELL environment variable will 254contain the shell specified in the password file. 255.It "term string Default terminal type if not able to determine" 256from other means. 257.It "timezone string Default value of $TZ environment variable." 258.It "umask number 022 Initial umask. Should always have a leading 0 to" 259ensure octal interpretation. 260.It "welcome file /etc/motd File containing welcome message." 261.El 262.Sh AUTHENTICATION 263.Bl -column passwd_prompt indent indent 264.It Sy "Name Type Notes Description" 265.\" .It "approve program Program to approve login. 266.It "copyright file File containing additional copyright information" 267.It "host.allow list List of remote host wildcards from which users in" 268the class may access. 269.It "host.deny list List of remote host wildcards from which users" 270in the class may not access. 271.It "login_prompt string The login prompt given by" 272.Xr login 1 273.It "login-backoff number 3 The number of login attempts" 274allowed before the backoff delay is inserted after each subsequent 275attempt. 276The backoff delay is the number of tries above 277.Em login-backoff 278multiplied by 5 seconds. 279.It "login-retries number 10 The number of login attempts" 280allowed before the login fails. 281.It "passwd_format string sha512 The encryption format that new or" 282changed passwords will use. 283Valid values include "des", "md5", "blf", "sha256" and "sha512"; see 284.Xr crypt 3 285for details. 286NIS clients using a 287.No non- Ns Fx 288NIS server should probably use "des". 289.It "passwd_prompt string The password prompt presented by" 290.Xr login 1 291.It "passwordtime time Used by" 292.Xr passwd 1 293to set next password expiry date. 294.It "times.allow list List of time periods during which" 295logins are allowed. 296.It "times.deny list List of time periods during which logins are" 297disallowed. 298.It "ttys.allow list List of ttys and ttygroups which users" 299in the class may use for access. 300.It "ttys.deny list List of ttys and ttygroups which users" 301in the class may not use for access. 302.It "warnexpire time Advance notice for pending account expiry." 303.It "warnpassword time Advance notice for pending password expiry." 304.\".It "widepasswords bool false Use the wide password format. The wide password 305.\" format allows up to 128 significant characters in the password. 306.El 307.Pp 308These fields are intended to be used by 309.Xr passwd 1 310and other programs in the login authentication system. 311.Pp 312Capabilities that set environment variables are scanned for both 313.Ql \&~ 314and 315.Ql \&$ 316characters, which are substituted for a user's home directory and name 317respectively. 318To pass these characters literally into the environment variable, escape 319the character by preceding it with a backslash '\\'. 320.Pp 321The 322.Em host.allow 323and 324.Em host.deny 325entries are comma separated lists used for checking remote access to the system, 326and consist of a list of hostnames and/or IP addresses against which remote 327network logins are checked. 328Items in these lists may contain wildcards in the form used by shell programs 329for wildcard matching (See 330.Xr fnmatch 3 331for details on the implementation). 332The check on hosts is made against both the remote system's Internet address 333and hostname (if available). 334If both lists are empty or not specified, then logins from any remote host 335are allowed. 336If host.allow contains one or more hosts, then only remote systems matching 337any of the items in that list are allowed to log in. 338If host.deny contains one or more hosts, then a login from any matching hosts 339will be disallowed. 340.Pp 341The 342.Em times.allow 343and 344.Em times.deny 345entries consist of a comma-separated list of time periods during which the users 346in a class are allowed to be logged in. 347These are expressed as one or more day codes followed by a start and end times 348expressed in 24 hour format, separated by a hyphen or dash. 349For example, MoThSa0200-1300 translates to Monday, Thursday and Saturday between 350the hours of 2 am and 1 p.m.. 351If both of these time lists are empty, users in the class are allowed access at 352any time. 353If 354.Em times.allow 355is specified, then logins are only allowed during the periods given. 356If 357.Em times.deny 358is specified, then logins are denied during the periods given, regardless of whether 359one of the periods specified in 360.Em times.allow 361applies. 362.Pp 363Note that 364.Xr login 1 365enforces only that the actual login falls within periods allowed by these entries. 366Further enforcement over the life of a session requires a separate daemon to 367monitor transitions from an allowed period to a non-allowed one. 368.Pp 369The 370.Em ttys.allow 371and 372.Em ttys.deny 373entries contain a comma-separated list of tty devices (without the /dev/ prefix) 374that a user in a class may use to access the system, and/or a list of ttygroups 375(See 376.Xr getttyent 3 377and 378.Xr ttys 5 379for information on ttygroups). 380If neither entry exists, then the choice of login device used by the user is 381unrestricted. 382If only 383.Em ttys.allow 384is specified, then the user is restricted only to ttys in the given 385group or device list. 386If only 387.Em ttys.deny 388is specified, then the user is prevented from using the specified devices or 389devices in the group. 390If both lists are given and are non-empty, the user is restricted to those 391devices allowed by ttys.allow that are not available by ttys.deny. 392.Pp 393The 394.Em minpasswordlen 395and 396.Em minpasswordcase 397facilities for enforcing restrictions on password quality, which used 398to be supported by 399.Nm , 400have been superseded by the 401.Xr pam_passwdqc 8 402PAM module. 403.Sh RESERVED CAPABILITIES 404The following capabilities are reserved for the purposes indicated and 405may be supported by third-party software. 406They are not implemented in the base system. 407.Bl -column host.accounted indent indent 408.It Sy "Name Type Notes Description" 409.It "accounted bool false Enable session time accounting for all users" 410in this class. 411.It "auth list passwd Allowed authentication styles." 412The first item is the default style. 413.It "auth-" Ns Ar type Ta "list Allowed authentication styles for the" 414authentication 415.Ar type . 416.It "autodelete time Time after expiry when account is auto-deleted." 417.It "bootfull bool false Enable 'boot only if ttygroup is full' strategy" 418when terminating sessions. 419.It "daytime time Maximum login time per day." 420.It "expireperiod time Time for expiry allocation." 421.It "graceexpire time Grace days for expired account." 422.It "gracetime time Additional grace login time allowed." 423.It "host.accounted list List of remote host wildcards from which" 424login sessions will be accounted. 425.It "host.exempt list List of remote host wildcards from which" 426login session accounting is exempted. 427.It "idletime time Maximum idle time before logout." 428.It "minpasswordlen number 6 The minimum length a local" 429password may be. 430.It "mixpasswordcase bool true Whether" 431.Xr passwd 1 432will warn the user if an all lower case password is entered. 433.It "monthtime time Maximum login time per month." 434.It "refreshtime time New time allowed on account refresh." 435.It "refreshperiod str How often account time is refreshed." 436.It "sessiontime time Maximum login time per session." 437.It "sessionlimit number Maximum number of concurrent" 438login sessions on ttys in any group. 439.It "ttys.accounted list List of ttys and ttygroups for which" 440login accounting is active. 441.It "ttys.exempt list List of ttys and ttygroups for which login accounting" 442is exempt. 443.It "warntime time Advance notice for pending out-of-time." 444.It "weektime time Maximum login time per week." 445.El 446.Pp 447The 448.Em ttys.accounted 449and 450.Em ttys.exempt 451fields operate in a similar manner to 452.Em ttys.allow 453and 454.Em ttys.deny 455as explained 456above. 457Similarly with the 458.Em host.accounted 459and 460.Em host.exempt 461lists. 462.Sh SEE ALSO 463.Xr cap_mkdb 1 , 464.Xr login 1 , 465.Xr chroot 2 , 466.Xr getcap 3 , 467.Xr getttyent 3 , 468.Xr login_cap 3 , 469.Xr login_class 3 , 470.Xr pam 3 , 471.Xr passwd 5 , 472.Xr ttys 5 , 473.Xr ftpd 8 , 474.Xr pam_passwdqc 8 475.Sh HISTORY 476The file 477.Nm 478first appeared in 479.Fx 2.1.5 . 480