Clarifications sought on Kerberos SA: TGS_REQ and Server Auth??

[Donn Cave]

In article <001101c5fb2a$76d25060$16466c6b at sisodomain.com>,
 surendra.a at samsung.com (Surendra Babu A) wrote:

> - Now we initiated the email operation from  Multi Funtion Printer. It 
> contacted the ESMTP server from ESMTP client.
> - Sent the EHLO command. ESMTP Server Gave me the AUTH GSSAPI response. So 
> Kerberos is supported at server sid. Right??
> - After seeing this GSSAPI string, sending the Service ticket to ESMTP 
> server.
> 
> Is it correct? We are assuming that, GSSPAI is supported means, Kerberos is 
> supported. Is it right?

Yes, all sounds right to me.

> Could you please explain about the Application Server transactions??? How to 
> communicate with GSSAPI?

If you have downloaded the MIT Kerberos distribution, you
could look at src/appl/gss-sample/.  Therein you will find
example code for a simple GSS application.

gss-sample uses functions like send_token() to transmit the
authentication data.  Your application won't use those, and
instead will send and receive authentication data according
to the ESMTP AUTH protocol.  That's probably explained in
an ESMTP RFC.

   Donn Cave, donn at u.washington.edu