RFR [13] JDK-8217610: TLSv1.3 fail with ClassException when EC keys are stored in PKCS11

[Xuelei Fan]

Hi,

Could I get the following update reviewed?
    http://cr.openjdk.java.net/~xuelei/8217610/webrev.00/

For EC key exchange in TLS connections, the private key should use the 
specified EC groups.  The current code is calling 
ECPrivateKey.getParams().  However, the private key may be not an 
instance of ECPrivateKey, for example for non-extractable private key in 
the SunPKCS11 provider.

To fix the tricky bug, in this update, if private key is an instance of 
ECPrivateKey, use it; otherwise, try to check the groups in the public 
key of the X.509 certificate bound to the private key.

No hardware to reproduce the issue, and no new regression test.  The 
update is straightforward.  Please help to check the patch if you can 
play with a hardware token.

Thanks,
Xuelei