I have working for a long time to get Drupal 7 to perform SSO authentication to a Windows Server 2003 environment.
What I have done so far:
Create a user account for the linux server in Active Directory. Had the Active Directory administrator execute the ktpass command to create a keytab file with the proper authentication types and SPN. Configure Kerberos in krb5.conf on the Linux server to reflect the specifics of our Active Directory environment. I am able to issue the kinit command against my own AD account and it authenticates. When I issue kvno to the SPN for the server account I just created I get the following: kvno: Ticket expired while getting credentials for HTTP/server_name.domain.com@DOMAIN.COM
I also have the keytab uploaded to the server. I just cannot get the KDC to issue a ticket for the SPN I created. Can anyone assist?