Provided by: login_4.1.4.1-1ubuntu2_i386 bug

НАЗВАНИЕ

       login.defs - содержит конфигурацию подсистемы теневых паролей

ОПИСАНИЕ

       Файл /etc/login.defs содержит настройки подсистемы теневых паролей
       (shadow password suite). Этот файл является обязательным. Отсутствие
       данного файла не повлияет на работу системы, но, вероятно, приведёт к
       выполнению нежелаемых операций.

       Файл представляет собой обычный текстовый файл; каждая строка описывает
       один параметр конфигурации. Строки состоят из названия параметра и его
       значения, которые разделяются пробельным символом. Пустые строки и
       комментарии игнорируются. Комментарии начинаются со знака фунта "#",
       который должен быть первым непробельным символом в строке.

       Parameter values may be of four types: strings, booleans, numbers, and
       long numbers. A string is comprised of any printable characters. A
       boolean should be either the value yes or no. An undefined boolean
       parameter or one with a value other than these will be given a no
       value. Numbers (both regular and long) may be either decimal values,
       octal values (precede the value with 0) or hexadecimal values (precede
       the value with 0x). The maximum value of the regular and long numeric
       parameters is machine-dependent.

       Возможны следующие параметры конфигурации:

       CHFN_RESTRICT (string)
           This parameter specifies which values in the gecos field of the
           /etc/passwd file may be changed by regular users using the chfn
           program. It can be any combination of letters f, r, w, h, for Full
           name, Room number, Work phone, and Home phone, respectively. For
           backward compatibility, yes is equivalent to rwh and no is
           equivalent to frwh. If not specified, only the superuser can make
           any changes. The most restrictive setting is better achieved by not
           installing chfn SUID.

       CONSOLE_GROUPS (string)
           List of groups to add to the user's supplementary groups set when
           logging in on the console (as determined by the CONSOLE setting).
           Default is none.

           Use with caution - it is possible for users to gain permanent
           access to these groups, even when not logged in on the console.

       CREATE_HOME (boolean)
           Indicate if a home directory should be created by default for new
           users.

           This setting does not apply to system users, and can be overriden
           on the command line.

       DEFAULT_HOME (boolean)
           Indicate if login is allowed if we can't cd to the home directory.
           Default in no.

           If set to yes, the user will login in the root (/) directory if it
           is not possible to cd to her home directory.

       ENCRYPT_METHOD (string)
           This defines the system default encryption algorithm for encrypting
           passwords (if no algorithm are specified on the command line).

           It can take one of these values:

           o   DES (default)

           o   MD5

           o   SHA256

           o   SHA512

               Note: this parameter overrides the MD5_CRYPT_ENAB variable.

               Note: This only affect the generation of group passwords. The
               generation of user passwords is done by PAM and subject to the
               PAM configuration. It is recommended to set this variable
               consistently with the PAM configuration.

           ENV_HZ (string)
               If set, it will be used to define the HZ environment variable
               when a user login. The value must be preceded by HZ=. A common
               value on Linux is HZ=100.

               The HZ environment variable is only set when the user (the
               superuser) logs in with sulogin.

           ENV_PATH (string)
               If set, it will be used to define the PATH environment variable
               when a regular user login. The value can be preceded by PATH=,
               or a colon separated list of paths (for example /bin:/usr/bin).
               The default value is PATH=/bin:/usr/bin.

           ENV_SUPATH (string)
               If set, it will be used to define the PATH environment variable
               when the superuser login. The value can be preceded by PATH=,
               or a colon separated list of paths (for example
               /sbin:/bin:/usr/sbin:/usr/bin). The default value is
               PATH=/bin:/usr/bin.

           ERASECHAR (number)
               Terminal ERASE character (010 = backspace, 0177 = DEL).

               The value can be prefixed "0" for an octal value, or "0x" for
               an hexadecimal value.

           FAIL_DELAY (number)
               Delay in seconds before being allowed another attempt after a
               login failure.

           FAKE_SHELL (string)
               If set, login will execute this shell instead of the users'
               shell specified in /etc/passwd.

           GID_MAX (number), GID_MIN (number)
               Range of group IDs used for the creation of regular groups by
               useradd, groupadd, or newusers.

           HUSHLOGIN_FILE (string)
               If defined, this file can inhibit all the usual chatter during
               the login sequence. If a full pathname is specified, then
               hushed mode will be enabled if the user's name or shell are
               found in the file. If not a full pathname, then hushed mode
               will be enabled if the file exists in the user's home
               directory.

           KILLCHAR (number)
               Terminal KILL character (025 = CTRL/U).

               The value can be prefixed "0" for an octal value, or "0x" for
               an hexadecimal value.

           LOG_OK_LOGINS (boolean)
               Enable logging of successful logins.

           LOG_UNKFAIL_ENAB (boolean)
               Enable display of unknown usernames when login failures are
               recorded.

               Note: logging unknown usernames may be a security issue if an
               user enter her password instead of her login name.

           LOGIN_RETRIES (number)
               Maximum number of login retries in case of bad password.

               This will most likely be overriden by PAM, since the default
               pam_unix module has it's own built in of 3 retries. However,
               this is a safe fallback in case you are using an authentication
               module that does not enforce PAM_MAXTRIES.

           LOGIN_TIMEOUT (number)
               Max time in seconds for login.

           MAIL_DIR (string)
               Почтовый каталог. Данный параметр нужен для управления почтовым
               ящиком при изменении или удалении учётной записи пользователя.
               Если параметр не задан, то используется значение указанное при
               сборке.

           MAIL_FILE (string)
               Defines the location of the users mail spool files relatively
               to their home directory.

           The MAIL_DIR and MAIL_FILE variables are used by useradd, usermod,
           and userdel to create, move, or delete the user's mail spool.

           MAX_MEMBERS_PER_GROUP (number)
               Maximum members per group entry. When the maximum is reached, a
               new group entry (line) is started in /etc/group (with the same
               name, same password, and same GID).

               The default value is 0, meaning that there are no limits in the
               number of members in a group.

               This feature (split group) permits to limit the length of lines
               in the group file. This is useful to make sure that lines for
               NIS groups are not larger than 1024 characters.

               If you need to enforce such limit, you can use 25.

               Note: split groups may not be supported by all tools (even in
               the Shadow toolsuite). You should not use this variable unless
               you really need it.

           MD5_CRYPT_ENAB (boolean)
               Indicate if passwords must be encrypted using the MD5-based
               algorithm. If set to yes, new passwords will be encrypted using
               the MD5-based algorithm compatible with the one used by recent
               releases of FreeBSD. It supports passwords of unlimited length
               and longer salt strings. Set to no if you need to copy
               encrypted passwords to other systems which don't understand the
               new algorithm. Default is no.

               This variable is superceded by the ENCRYPT_METHOD variable or
               by any command line option used to configure the encryption
               algorithm.

               This variable is deprecated. You should use ENCRYPT_METHOD.

               Note: This only affect the generation of group passwords. The
               generation of user passwords is done by PAM and subject to the
               PAM configuration. It is recommended to set this variable
               consistently with the PAM configuration.

           PASS_MAX_DAYS (number)
               Максимальное число дней использования пароля. Если пароль
               старее этого числа, то будет запущена процедура смены пароля.
               Если значение не задано, то предполагается значение -1 (то есть
               возможность ограничения не используется).

           PASS_MIN_DAYS (number)
               Максимальное число дней между изменениями пароля. Любая смена
               пароля ранее заданного срока выполнена не будет. Если значение
               не задано, то предполагается значение -1 (то есть возможность
               ограничения не используется).

           PASS_WARN_AGE (number)
               Число дней за которое начнёт выдаваться предупреждение об
               устаревании пароля. Нулевое значение означает, что
               предупреждение выдаётся в день устаревания, при отрицательном
               значении предупреждение выдаваться не будет. Если значение не
               задано, выдача предупреждения отключается.

           PASS_MAX_DAYS, PASS_MIN_DAYS and PASS_WARN_AGE are only used at the
           time of account creation. Any changes to these settings won't
           affect existing accounts.

           SHA_CRYPT_MIN_ROUNDS (number), SHA_CRYPT_MAX_ROUNDS (number)
               When ENCRYPT_METHOD is set to SHA256 or SHA512, this defines
               the number of SHA rounds used by the encryption algorithm by
               default (when the number of rounds is not specified on the
               command line).

               With a lot of rounds, it is more difficult to brute forcing the
               password. But note also that more CPU resources will be needed
               to authenticate users.

               If not specified, the libc will choose the default number of
               rounds (5000).

               The values must be inside the 1000-999999999 range.

               If only one of the SHA_CRYPT_MIN_ROUNDS or SHA_CRYPT_MAX_ROUNDS
               values is set, then this value will be used.

               If SHA_CRYPT_MIN_ROUNDS > SHA_CRYPT_MAX_ROUNDS, the highest
               value will be used.

               Note: This only affect the generation of group passwords. The
               generation of user passwords is done by PAM and subject to the
               PAM configuration. It is recommended to set this variable
               consistently with the PAM configuration.

           SULOG_FILE (string)
               If defined, all su activity is logged to this file.

           SU_NAME (string)
               If defined, the command name to display when running "su -".
               For example, if this is defined as "su" then a "ps" will
               display the command is "-su". If not defined, then "ps" would
               display the name of the shell actually being run, e.g.
               something like "-sh".

           SYS_GID_MAX (number), SYS_GID_MIN (number)
               Range of group IDs used for the creation of system groups by
               useradd, groupadd, or newusers.

           SYS_UID_MAX (number), SYS_UID_MIN (number)
               Range of user IDs used for the creation of system users by
               useradd or newusers.

           SYSLOG_SG_ENAB (boolean)
               Enable "syslog" logging of sg activity.

           SYSLOG_SU_ENAB (boolean)
               Enable "syslog" logging of su activity - in addition to sulog
               file logging.

           TTYGROUP (string), TTYPERM (string)
               The terminal permissions: the login tty will be owned by the
               TTYGROUP group, and the permissions will be set to TTYPERM.

               By default, the ownership of the terminal is set to the user's
               primary group and the permissions are set to 0600.

               TTYGROUP can be either the name of a group or a numeric group
               identifier.

               If you have a write program which is "setgid" to a special
               group which owns the terminals, define TTYGROUP to the group
               number and TTYPERM to 0620. Otherwise leave TTYGROUP commented
               out and assign TTYPERM to either 622 or 600.

           TTYTYPE_FILE (string)
               If defined, file which maps tty line to TERM environment
               parameter. Each line of the file is in a format something like
               "vt100 tty01".

           UID_MAX (number), UID_MIN (number)
               Range of user IDs used for the creation of regular users by
               useradd or newusers.

           UMASK (number)
               The file mode creation mask is initialized to this value. If
               not specified, the mask will be initialized to 022.

               useradd and newusers use this mask to set the mode of the home
               directory they create

           USERDEL_CMD (string)
               Определяет программу, которая будет запущена при удалении
               пользователя. Она должна удалять любые задания at/cron/печати
               удаляемого пользователя (передаётся в качестве первого
               аргумента).

               The return code of the script is not taken into account.

               Here is an example script, which removes the user's cron, at
               and print jobs:

                   #! /bin/sh

                   # Check for the required argument.
                   if [ $# != 1 ]; then
                        echo "Usage: $0 username"
                        exit 1
                   fi

                   # Remove cron jobs.
                   crontab -r -u $1

                   # Remove at jobs.
                   # Note that it will remove any jobs owned by the same UID,
                   # even if it was shared by a different username.
                   AT_SPOOL_DIR=/var/spool/cron/atjobs
                   find $AT_SPOOL_DIR -name "[^.]*" -type f -user $1 -delete \;

                   # Remove print jobs.
                   lprm $1

                   # All done.
                   exit 0

           USERGROUPS_ENAB (boolean)
               If set to yes, userdel will remove the user's group if it
               contains no more members, and useradd will create by default a
               group with the name of the user.

CROSS REFERENCES

       The following cross references show which programs in the shadow
       password suite use which parameters.

       chfn
           CHFN_RESTRICT

       chgpasswd
           ENCRYPT_METHOD MAX_MEMBERS_PER_GROUP MD5_CRYPT_ENAB
           SHA_CRYPT_MAX_ROUNDS SHA_CRYPT_MIN_ROUNDS

       gpasswd
           ENCRYPT_METHOD MAX_MEMBERS_PER_GROUP MD5_CRYPT_ENAB
           SHA_CRYPT_MAX_ROUNDS SHA_CRYPT_MIN_ROUNDS

       groupadd
           GID_MAX GID_MIN MAX_MEMBERS_PER_GROUP SYS_GID_MAX SYS_GID_MIN

       groupdel
           MAX_MEMBERS_PER_GROUP

       groupmems
           MAX_MEMBERS_PER_GROUP

       groupmod
           MAX_MEMBERS_PER_GROUP

       grpck
           MAX_MEMBERS_PER_GROUP

       grpconv
           MAX_MEMBERS_PER_GROUP

       grpunconv
           MAX_MEMBERS_PER_GROUP

       login
           CONSOLE_GROUPS DEFAULT_HOME ERASECHAR FAIL_DELAY FAKE_SHELL
           HUSHLOGIN_FILE KILLCHAR LOGIN_RETRIES LOGIN_TIMEOUT LOG_OK_LOGINS
           LOG_UNKFAIL_ENAB TTYGROUP TTYPERM TTYTYPE_FILE USERGROUPS_ENAB

       newgrp / sg
           SYSLOG_SG_ENAB

       newusers
           ENCRYPT_METHOD GID_MAX GID_MIN MAX_MEMBERS_PER_GROUP MD5_CRYPT_ENAB
           PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE SHA_CRYPT_MAX_ROUNDS
           SHA_CRYPT_MIN_ROUNDS SYS_GID_MAX SYS_GID_MIN SYS_UID_MAX
           SYS_UID_MIN UID_MAX UID_MIN UMASK

       pwck
           PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE

       pwconv
           PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE

       su
           CONSOLE_GROUPS DEFAULT_HOME ENV_PATH ENV_SUPATH SULOG_FILE SU_NAME
           SYSLOG_SU_ENAB

       sulogin
           ENV_HZ

       useradd
           CREATE_HOME GID_MAX GID_MIN MAIL_DIR MAX_MEMBERS_PER_GROUP
           PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE SYS_GID_MAX SYS_GID_MIN
           SYS_UID_MAX SYS_UID_MIN UID_MAX UID_MIN UMASK

       userdel
           MAIL_DIR MAIL_FILE MAX_MEMBERS_PER_GROUP USERDEL_CMD
           USERGROUPS_ENAB

       usermod
           MAIL_DIR MAIL_FILE MAX_MEMBERS_PER_GROUP

ОШИБКИ РЕАЛИЗАЦИИ

       Much of the functionality that used to be provided by the shadow
       password suite is now handled by PAM. Thus, /etc/login.defs is no
       longer used by passwd(1), or less used by login(1), and su(1). Please
       refer to the corresponding PAM configuration files instead.

СМОТРИТЕ ТАКЖЕ

       login(1), passwd(1), su(1), passwd(5), shadow(5), pam(8).