ad-initial-verified-cas logic broken

ad-initial-verified-cas logic broken

In the initial pkinit implementation, the server plugin generates an
incorrect encoding for ad-initial-verified-cas.  In particular, it
assumes that ad-if-relevant takes a single authorization data element
not a sequence of authorization data elements.  Nothing looked at the
authorization data in 1.6.3 so this was not noticed.  However in 1.7,
the FAST implementation looks for authorization data.  In 1.8 several
more parts of the KDC examine authorization data.  The net result is
that the KDC fails to process the TGT it issues.

However on top of this bug, there is a spec problem.  For many of its intended uses, ad-initial-verified-cas needs to be integrity protected by the KDC in order to prevent a client from injecting it.  So, it should be contained in kdc-issued not ad-if-relevant.

For now we're simply removing the generation of this AD element until the spec is clarified.

ticket: 6587
status: open

git-svn-id: svn://anonsvn.mit.edu/krb5/branches/anonymous@23492 dc483132-0cff-0310-8789-dd5450dbe970