userdb(4)						     Kernel Interfaces Manual							 userdb(4)

NAME

       userdb - user database for per-user information

SYNOPSIS

DESCRIPTION

       The  user  database  is	used for storing per-user information.	It consists of the directory and the files within it.  Each file name is a
       two-digit hexadecimal number from to The directory and files are created either at installation time or by the command.

       The per-user information resides in user entries in the database, and consists of any number of pairs, which are used to define the  behav-
       ior  of configurable features.  A per-user value in overrides any corresponding system-wide default configured in the file, as described in
       security(4).

       The file indicates which attributes can be configured with a per-user value in This  list  includes  the  following  attributes	which  are
       described in security(4):

       Allow or do not allow null passwords.

       Audit or do not audit users.

       Maximum number of authentication failures allowed.

       Display or do not display last login information.

       Restrict login time periods.

       Minimum password length.

       Number of simultaneous logins allowed per user.

       Password history depth.
	      Minimum number of lower case characters allowed in a password.

       Minimum number of upper case characters allowed in a password.
	      Minimum number of digit characters allowed in a password.

       Minimum number of special characters allowed in a password.

       Define umask for file creation.

   Notes
       When defining attributes, first configure default values in as described in security(4), and then configure per-user exceptions in the user
       database,

       In addition to the configurable attributes, there are internal attributes that are not user configurable and are normally modified only	by
       programs that enforce system security.  The file indicates which attributes are configurable and which are internal.

       Use the command to verify or fix information in the user database,

       To  disable  the  user database, create a file called This causes all database reads and writes to return an error code indicating that the
       database is disabled and should be ignored.  Note that, if the user database is disabled for a long period and  then  re-enabled,  it  will
       contain stale data.  This can cause unwanted side effects.

WARNINGS

       Use  the command to modify information in Do not use a text editor, because the database contains checksums and other binary data, and edi-
       tors do not follow the file locking conventions that are used to control access to the database.

       NFS mounting this database is not supported.

FILES

       user database
       security defaults configuration file
       security attributes description file

SEE ALSO

       userdbck(1M), userdbget(1M), userdbset(1M), userdb_read(3), security(4).

																	 userdb(4)