Provided by: login_4.0.13-7ubuntu3_i386 bug

NAME

       login.defs - shadow password suite configuration

DESCRIPTION

       The /etc/login.defs file defines the site-specific configuration for
       the shadow password suite. This file is required. Absence of this file
       will not prevent system operation, but will probably result in
       undesirable operation.

       This file is a readable text file, each line of the file describing one
       configuration parameter. The lines consist of a configuration name and
       value, separated by whitespace. Blank lines and comment lines are
       ignored. Comments are introduced with a ‘#’ pound sign and the pound
       sign must be the first non-white character of the line.

       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.

       The following configuration items are provided:

       CHFN_AUTH (boolean)
              If yes, the chfn and chsh programs will require authentication
              before making any changes, unless run by the superuser.

       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.

       CREATE_HOME (boolean)
              This defines whether useradd should create home directories for
              users by default. This option is OR’ed with the -m flag on
              useradd command line.

       GID_MAX (number), GID_MIN (number)
              Range of group IDs to choose from for the useradd and groupadd
              programs.

       MAIL_DIR (string)
              The mail spool directory. This is needed to manipulate the
              mailbox when its corresponding user account is modified or
              deleted. If not specified, a compile-time default is used.

       PASS_MAX_DAYS (number)
              The maximum number of days a password may be used. If the
              password is older than this, a password change will be forced.
              If not specified, -1 will be assumed (which disables the
              restriction).

       PASS_MIN_DAYS (number)
              The minimum number of days allowed between password changes. Any
              password changes attempted sooner than this will be rejected. If
              not specified, -1 will be assumed (which disables the
              restriction).

       PASS_WARN_AGE (number)
              The number of days warning given before a password expires. A
              zero means warning is given only upon the day of expiration, a
              negative value means no warning is given. If not specified, no
              warning will be provided.

       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.

       UID_MAX (number), UID_MIN (number)
              Range of user IDs to choose from for the useradd program.

       UMASK (number)
              The permission mask is initialized to this value. If not
              specified, the permission mask will be initialized to 077.

       USERDEL_CMD (string)
              If defined, this command is run when removing a user. It should
              remove any at/cron/print jobs etc. owned by the user to be
              removed (passed as the first argument).

CROSS REFERENCE

       The following cross reference shows which programs in the shadow
       password suite use which parameters.

       chfn   CHFN_AUTH CHFN_RESTRICT

       chsh   CHFN_AUTH

       groupadd
              GID_MAX GID_MIN

       newusers
              PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE UMASK

       pwconv PASS_MAX_DAYS PASS_MIN_DAYS PASS_WARN_AGE

       useradd
              CREATE_HOME GID_MAX GID_MIN PASS_MAX_DAYS PASS_MIN_DAYS
              PASS_WARN_AGE UID_MAX UID_MIN UMASK

       userdel
              MAIL_DIR USERDEL_CMD

       usermod
              MAIL_DIR

BUGS

       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 programs such as: login(1), passwd(1), su(1). Please
       refer to the corresponding PAM configuration files instead.

SEE ALSO

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

AUTHORS

       Julianne Frances Haugh (jockgrrl@ix.netcom.com) Chip Rosenthal
       (chip@unicom.com)

                                  09/30/2005                     LOGIN.DEFS(5)