port ] [
keytab ] [
sserver and sclient are a simple demonstration
client/server application. When sclient connects to
sserver, it performs a Kerberos authentication, and then
sserver returns to sclient the Kerberos
principal which was used for the Kerberos authentication. It makes a
good test that Kerberos has been successfully installed on a machine.
The service name used by sserver and sclient is
sample. Hence, sserver will require that there be a keytab
entry for the service "sample/[email protected]". This
keytab is generated using the
program. The keytab file is usually installed as "/etc/krb5.keytab".
option allows for a different keytab than the default.
sserver is normally invoked out of
using a line in
/etc/inetd.conf that looks like this:
sample stream tcp nowait root /usr/sbin/sserver sserver
Since sample is normally not a port defined in /etc/services, you will
usually have to add a line to /etc/services which looks like this:
When using sclient, you will first have to have an entry in the Kerberos
database, by using
and then you have to get Kerberos
tickets, by using
Also, if you are running the sclient
program on a different host than the sserver it will be
connecting to, be
sure that both hosts have an entry in /etc/services for the sample tcp
port, and that the same port number is in both files.
When you run sclient you should see something like this:
sendauth succeeded, reply is:
reply len 32, contents:
You are [email protected]
1) kinit returns the error:
kinit: Client not found in Kerberos database while getting initial credentials
This means that you didn’t create an entry for your username in the
2) sclient returns the error:
unknown service sample/tcp; check /etc/services
This means that you don’t have an entry in /etc/services for the
sample tcp port.
3) sclient returns the error:
connect: Connection refused
This probably means you didn’t edit /etc/inetd.conf correctly, or you
didn’t restart inetd after editing inetd.conf.
4) sclient returns the error:
sclient: Server not found in Kerberos database while using sendauth
This means that the "sample/[email protected]" service was not
defined in the Kerberos database; it should be created using kadmin,
and a keytab file needs to be generated to make the key for that service
principal available for ssclient.
5) sclient returns the error:
sendauth rejected, error reply is:
" No such file or directory"
This probably means sserver couldn’t find the keytab file. It was
probably not installed in the proper directory.