RFR JDK-8240871: SSLEngine handshake status immediately after the handshake can be NOT_HANDSHAKING rather than FINISHED with TLSv1.3

[Xuelei Fan]

Hi,

Could I get the following update reviewed:
     http://cr.openjdk.java.net/~xuelei/8240871/webrev.00/

For TLS 1.3 full handshake, if the last handshake flight wraps the 
Finished together with other handshake message, for example client 
certificate, the flight could be wrapped and encrypted in one record and 
delegated tasks would be used.  There is no chance to return FINISHED 
handshake status with SSLEngine.(un)wrap(). However, per the 
HandshakeStatus.FINISHED specification, this handshake status is only 
generated by a call to SSLEngine.wrap()/unwrap() and it is never 
generated by SSLEngine.getHandshakeStatus().

In order to workaround this case for TLS 1.3, the FINISHED status could 
present with SSLEngine.wrap() while delivering of the NewSessionTicket 
post-handshake message.  If this post-handshake message is not needed, a 
follow-on SSLEngine.wrap() should be called to indicate the FINISHED 
handshake status.  Although this special SSLEngine.wrap() should not 
consume or produce any application or network data.

I also clean up some debug log, names and code style a little bit.

The update could be confirmed with Tomcat and Firefox in private mode, 
as described in the bug description.  As this case happens only when 
psk_key_exchange_modes does not present, which is not a behavior 
supported by JDK, I did not find a workaround for a new regression test 
yet.  I added the labels, noreg-external and noreg-hard.

Thanks,
Xuelei