RFR: 8314323: Implement JEP 527: TLS 1.3 Hybrid Key Exchange [v6]

[Artur Barashev]

On Wed, 15 Oct 2025 06:48:50 GMT, Hai-May Chao <hchao at openjdk.org> wrote:

>> Implement hybrid key exchange support for TLS 1.3 by adding three post-quantum hybrid named groups: X25519MLKEM768, SecP256r1MLKEM768, and SecP384r1MLKEM1024.
>> Please see [JEP 527](https://openjdk.org/jeps/527) for details about this change.
>
> Hai-May Chao has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Revert changes to UseStrongDHSizes test as ffdhe6144/8192 added back
>  - Updated comment in ServerHello and hybrid to upper-case in NamedGroup

src/java.base/share/classes/java/security/spec/NamedParameterSpec.java line 141:

> 139:      * @since 26
> 140:      */
> 141:     public static final NamedParameterSpec SecP384r1MLKEM1024

Nit: Let's make these all upper-case as well to keep things consistent across files.

test/jdk/javax/net/ssl/TLSCommon/NamedGroup.java line 44:

> 42:     X25519MLKEM768("X25519MLKEM768"),
> 43:     SecP256r1MLKEM768("SecP256r1MLKEM768"),
> 44:     SecP384r1MLKEM1024("SecP384r1MLKEM1024");

Nit: Make those uppercase.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27614#discussion_r2432782187
PR Review Comment: https://git.openjdk.org/jdk/pull/27614#discussion_r2432785713