SHADOW(W)                                               SHADOW(W)



NAME
       shadow - encrypted password file

DESCRIPTION
       shadow  contains  the  encrypted  password information for
       user's accounts and optional the password  aging  informa-
       tion.  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(t) for details on how this  string  is  interpreted.
       If  the  password  field  contains some string that is not
       valid result of crypt(t), for instance ! or  *,  the  user
       will not be able to use a unix password to log in, subject
       to pam(m).

       The date of the last password change is given as the  num-
       ber  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 maximum 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 regardless 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 pass-
       word security is to be maintained.

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

SEE ALSO
       chage(e),   login(n),   passwd(d),   su(u),    sulogin(n),
       passwd(d), pwconv(v), pwunconv(v)

AUTHOR
       Julianne Frances Haugh (jfh@austin.ibm.com)



                                                        SHADOW(W)