two new methods should be added to java.security.cert.X509Certificate:

> javax.security.auth.x500.X500Principal getIssuerX500Principal()
> javax.security.auth.x500.X500Principal getSubjectX500Principal()

currently, applications call:

java.security.Principal getIssuerDN()
java.security.Principal getSubjectDN()

the returned class is vendor-specific and therefore applications
can not interoperate efficiently. by returning the new public
javax.security.auth.x500.X500Principal class, applications
can rely on a common public X500Principal class.

as part of this fix, sun.security.x509.X500Name will no longer
subclass javax.security.auth.X500Principal,
and X500Principal will no longer have a protected no-arg constructor
(which was necessary to allow X500Name to subclass it).