RFR: 8328046: Need to keep leading zeros in TlsPremasterSecret of TLS1.3 DHKeyAgreement [v2]

[Daniel Jeliński]

> TLS 1.3 changed the way it generates the FFDHE shared secret. In TLS 1.2, the leading zeroes in the shared secret were stripped, and in TLS 1.3 the leading zeroes are preserved.
> 
> Thanks to the recent work in [JDK-8189441](https://bugs.openjdk.org/browse/JDK-8189441), we now have a new algorithm name `Generic` that can be used to generate a shared secret with the leading zeroes preserved.
> 
> This PR changes the TLS 1.3 handshake to use the new algorithm name. It also fixes a bug in PKCS11 Generic key derivation, and updates the existing tests to verify that the Generic algorithm doesn't strip leading zeroes.
> 
> I didn't add any tests to verify the correctness of the handshake. This can be verified using tlsfuzzer, see JBS for details.
> 
> Tier1-3 tests continue to pass. The `TestLeadingZeroesP11.java` test fails before the `P11KeyAgreement.java` changes, passes after.

Daniel Jeliński has updated the pull request incrementally with one additional commit since the last revision:

  Revert PKCS11 changes

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/27343/files
  - new: https://git.openjdk.org/jdk/pull/27343/files/7c39df58..7104ae3e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27343&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27343&range=00-01

  Stats: 84 lines in 3 files changed: 23 ins; 51 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/27343.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27343/head:pull/27343

PR: https://git.openjdk.org/jdk/pull/27343