Hadoop 2.3 includes miniKdc module. This provides a KDC that can be used by downstream projects to implement unit tests for Kerberos authentication code.
Hive has lot of code related to Kerberos and delegation token for authentication, as well as accessing secure hadoop resources. This pretty much has no coverage in the unit tests. We needs to add unit tests using miniKdc module.
Note that Hadoop 2.3 doesn't include a secure mini-cluster. Until that is available, we can at least test authentication for components like HiveServer2, Metastore and WebHCat.