Your Kerberos database contains all of your realm's Kerberos principals,
their passwords, and other administrative information about each
principal. For the most part, you will use the kdb5_util program
to manipulate the Kerberos database as a whole, and the kadmin
program to make changes to the entries in the database. (One notable
exception is that users will use the kpasswd program to change
their own passwords.) The kadmin program has its own
command-line interface, to which you type the database administrating
commands.
Kdb5_util provides a means to create, delete, load, or dump a
Kerberos database. It also includes a command to stash a copy of the
master database key in a file on a KDC, so that the KDC can authenticate
itself to the kadmind and krb5kdc daemons at boot time.
Kadmin provides for the maintenance of Kerberos principals, KADM5
policies, and service key tables (keytabs). It exists as both a
Kerberos client, kadmin, using Kerberos authentication and an
RPC, to operate securely from anywhere on the network, and as a local
client, kadmin.local, intended to run directly on the KDC without
Kerberos authentication. Other than the fact that the remote client
uses Kerberos to authenticate the person using it, the functionalities
of the two versions are identical. The local version is necessary to
enable you to set up enough of the database to be able to use the remote
version. It replaces the now obsolete kdb5_edit (except for
database dump and load, which are provided by kdb5_util).
The remote version authenticates to the KADM5 server using the service
principal kadmin/admin. If the credentials cache contains a
ticket for the kadmin/admin principal, and the -c ccache
option is specified, that ticket is used to authenticate to KADM5.
Otherwise, the -p and -k options are used to specify the
client Kerberos principal name used to authenticate. Once kadmin has
determined the principal name, it requests a kadmin/admin
Kerberos service ticket from the KDC, and uses that service ticket to
authenticate to KADM5.