kdc - Kerberos 5 server
kdc [-c file | --config-file=file] [-p |
--no-require-preauth]
[--max-request=size] [-H | --enable-http] [--no-524]
[--kerberos4]
[--kerberos4-cross-realm] [-r string |
--v4-realm=string]
[-K | --kaserver] [-P portspec | --ports=portspec]
[--detach]
[--addresses=list of addresses]
kdc serves requests for tickets. When it starts, it first
checks the
flags passed, any options that are not specified with a command line flag
are taken from a config file, or from a default compiled-in
value.
Options supported:
-c file, --config-file=file
Specifies the location of the config file, the default is
/var/heimdal/kdc.conf. This is the only value that
can't be
specified in the config file.
-p, --no-require-preauth
Turn off the requirement for pre-autentication in
the initial ASREQ
for all principals. The use of pre-authentication makes it
more difficult to do offline password attacks. You
might want to
turn it off if you have clients that don't support
pre-authentication.
Since the version 4 protocol doesn't support any pre-authentication,
serving version 4 clients is just
about the same as
not requiring pre-athentication. The default is to
require preauthentication.
Adding the require-preauth per
principal is a
more flexible way of handling this.
--max-request=size
Gives an upper limit on the size of the requests
that the kdc is
willing to handle.
--kerberos4-cross-realm
respond to kerberos 4 requests from foreign realms.
This is a
known security hole and should not be enabled unless
you understand
the consequences and are willing to live with
them.
-H, --enable-http
Makes the kdc listen on port 80 and handle requests
encapsulated
in HTTP.
--no-524
don't respond to 524 requests
--kerberos4
respond to Kerberos 4 requests
--kerberos4-cross-realm
respond to Kerberos 4 requests from foreign realms.
This is a
known security hole and should not be enabled unless
you understand
the consequences and are willing to live with
them.
-r string, --v4-realm=string
What realm this server should act as when dealing
with version 4
requests. The database can contain any number of
realms, but
since the version 4 protocol doesn't contain a realm
for the
server, it must be explicitly specified. The default is whatever
is returned by krb_get_lrealm(). This option is only availabe if
the KDC has been compiled with version 4 support.
-K, --kaserver
Enable kaserver emulation (in case it's compiled
in).
-P portspec, --ports=portspec
Specifies the set of ports the KDC should listen on.
It is given
as a white-space separated list of services or port
numbers.
--addresses=list of addresses
The list of addresses to listen for requests on. By
default, the
kdc will listen on all the locally configured addresses. If only
a subset is desired, or the automatic detection
fails, this option
might be used.
All activities are logged to one or more destinations, see
krb5.conf(5),
and krb5_openlog(3). The entity used for logging is kdc.
The configuration file has the same syntax as krb5.conf(5),
but will be
read before /etc/kerberosV/krb5.conf, so it may override
settings found
there. Options specific to the KDC only are found in the
``[kdc]'' section.
All the command-line options can preferably be added
in the configuration
file. The only difference is the pre-authentication flag,
which has to be specified as:
require-preauth = no
(in fact you can specify the option as
--require-preauth=no).
And there are some configuration options which do not have
command-line
equivalents:
check-ticket-addresses = boolean
Check the addresses in the ticket when processing
TGS requests.
The default is FALSE.
allow-null-ticket-addresses = boolean
Permit tickets with no addresses. This option is
only relevant
when check-ticket-addresses is TRUE.
allow-anonymous = boolean
Permit anonymous tickets with no addresses.
transited-policy = always-check | allow-per-principal
| always-honour-request
This controls how KDC requests with the disabletransitedcheck
flag are handled. It can be one of:
always-check
Always check transited encoding, this
is the default.
allow-per-principal
Currently this is identical to alwayscheck. In a
future release, it will be possible to
mark a principal
as able to handle unchecked requests.
always-honour-request
Always do what the client asked. In a
future release,
it will be possible to force a
check per
principal.
encode_as_rep_as_tgs_rep = boolean
Encode AS-Rep as TGS-Rep to be bug-compatible
with old DCE
code. The Heimdal clients allow both.
kdc_warn_pwexpire = time
How long before password/principal expiration the
KDC should
start sending out warning messages.
The configuration file is only read when the kdc is started.
If changes
made to the configuration file are to take effect, the kdc
needs to be
restarted.
An example of a config file:
[kdc]
require-preauth = no
v4-realm = FOO.SE
key-file = /key-file
If the machine running the KDC has new addresses added to
it, the KDC
will have to be restarted to listen to them. The reason it
doesn't just
listen to wildcarded (like INADDR_ANY) addresses, is that
the replies has
to come from the same address they were sent to, and most
OS:es doesn't
pass this information to the application. If your normal
mode of operation
require that you add and remove addresses, the best option is probably
to listen to a wildcarded TCP socket, and make sure your
clients use
TCP to connect. For instance, this will listen to IPv4 TCP
port 88 only:
kdc --addresses=0.0.0.0 --ports="88/tcp"
There should be a way to specify protocol, port, and address
triplets,
not just addresses and protocol, port tuples.
kinit(1), krb5.conf(5)
HEIMDAL October 22, 2003
[ Back ] |
