RFR 8014628: Support AES Encryption with HMAC-SHA2 for Kerberos 5

[Weijun Wang]

Hi All

Please take a review at

   http://cr.openjdk.java.net/~weijun/8014628/webrev.00/

Most changes are just duplicating existing classes/methods/fields on AES-SHA1 etypes. One day we might do some refactoring to simplify this.

Real changes:

- AesSha2DkCrypto.java:

1. A new dr() method, explained in https://tools.ietf.org/html/rfc8009#section-3

2. etype name used in stringToKey(), explained in https://tools.ietf.org/html/rfc8009#section-4

3. A separate deriveKey() method. Not only it reduces duplicated codes, but it is also used in KerberosAesSha2.java the test.

- Config.java:

Previous AES-SHA1 etypes now have aliases aes128-sha1 and aes256-sha1.

- EType.java:

The default enctypes set now includes the new aes-sha2 etypes, but aes-sha1 etypes are more preferred. This is also what MIT krb5 is doing.

- KerberosAesSha2.java

Test vectors in https://tools.ietf.org/html/rfc8009#appendix-A.

Thanks
Max