shadow (5)





NAME

       shadow - encrypted password file


DESCRIPTION

       shadow  contains the encrypted password information for user's accounts
       and optional the password aging information.  Included is

            Login name

            Encrypted password

            Days since Jan 1, 1970 that password was last changed

            Days before password may be changed

            Days after which password must be changed

            Days before password is to expire that user is warned

            Days after password expires that account is disabled

            Days since Jan 1, 1970 that account is disabled

            A reserved field

       The password field must be filled.  The encryped password  consists  of
       13  to 24 characters from the 64 character alphabet a thru z, A thru Z,
       0 thru 9, . and /.  Refer to crypt(3) for details on how this string is
       interpreted.

       The  date  of  the  last password change is given as the number of days
       since Jan 1, 1970.  The password may not be  changed  again  until  the
       proper  number of days have passed, and must be changed after the maxi-
       mum number of days.  If the minimum number of days required is  greater
       than  the  maximum  number  of  day  allowed,  this password may not be
       changed by the user.

       An account is considered to be inactive and is disabled if the password
       is  not  changed within the specified number of days after the password
       expires.  An account will also be disabled on the specified day regard-
       less of other password expiration information.

       This  information  supercedes  any password or password age information
       present in /etc/passwd.

       This file must not be readable by regular users if password security is
       to be maintained.


FILES

       /etc/passwd - user account information
       /etc/shadow - encrypted user passwords


SEE ALSO

       chage(1),  login(1),  passwd(1),  su(1),  passwd(5),  pwconv(8),  pwun-
       conv(8), sulogin(8)