Is it possible to have a Java process running on linux access EWS using kerberos only without the need of a pre-defined username/password combination?
My current system architecture consists of a Java process that accesses EWS using a stored username/password combination. Requirement is to ensure that the credentials under which the Java process runs are authenticated on Exchange using Kerberos.
Is it possible to have this setup?
You ticket a TGT in the ticket cache or a keytab for that account.
yes, it should be possible to authenticate to EWS using Kerberos. You can Java GSSAPI to get the Kerberos tickets (from the ticket cache or prompt the user). There is a Java GSS Sample program at http://docs.oracle.com/javase/1.5.0/docs/guide/security/jgss/tutorials/BasicClientServer.html
Your question seems to be more on what Java can do versus what Exchange/IIS can do. I don't know Java well at all, however I do know EWS and IIS topics well.
Here is something to keep in mind - IIS does the authentication and not EWS. You could do an HTTP GET on a file in a virtual folder on an IIS server to verify that your API works. If you can authenticate to IIS, then EWS should work. Now having said that you also need do consifer access issues - ie impersonation and delegateion - you will need to be sure you have the needed content in the EWS XML and have the correct Exchange settings for Impersonation and correct folder permissions set for delegation.
Yes, it is possible. It is already implemented in "JWebServices for Exchange", Java API for EWS