k5login(5)

     NAME
     DESCRIPTION
          The .k5login file, which resides in a user's home directory,
          contains a list of the Kerberos principals.  Anyone with
          valid tickets for a principal in the file is allowed host
          access with the UID of the user in whose home directory the
          file resides.  One common use is to place a .k5login file in
          root's home directory, thereby granting system
          administrators remote root access to the host via Kerberos.

     EXAMPLES
          Suppose the user "janedoe" had a .k5login file in her home
          directory containing the following line:

                    johndoe@FUBAR.ORG

          This would allow her husband "johndoe" to use any of the
          Kerberos network applications, such as telnet(1), rlogin(1),
          rsh(1), and rcp(1), to access her account, using his own
          Kerberos tickets.

          Let us further suppose that "janedoe" is a system
          administrator.  She and the other system administrators
          would have their principals in root's .k5login file on each
          host:

                    janedoe@BLEEP.COM
                    joeadmin/root@BLEEP.COM

          This would allow either system administrator to log in to
          these hosts using their Kerberos tickets instead of having
          to type the root password.  Note that because "janedoe"'s
          husband retains the Kerberos tickets for his own principal,
          "johndoe@FUBAR.ORG", he would not have any of the privileges
          that require his wife's tickets, such as root access to any
          of her site's hosts, or the ability to change her password.

     SEE ALSO
          telnet(1), rlogin(1), rsh(1), rcp(1), ksu(1), telnetd(8),
          klogind(8)