RFR: 8314323: Implement JEP 527: TLS 1.3 Hybrid Key Exchange [v9]

[Deirdre Connolly]

On Mon, 24 Nov 2025 07:51:40 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 three additional commits since the last revision:
> 
>  - Update names to uppercase
>  - Remove fallback in engineGeneratePublic
>  - Change default named group list to have only X25519MLKEM768

src/java.base/share/classes/sun/security/ssl/NamedGroup.java line 231:

> 229:     ML_KEM_1024(0x0202, "MLKEM1024",
> 230:             NamedGroupSpec.NAMED_GROUP_KEM,
> 231:             ProtocolVersion.PROTOCOLS_OF_13,

These are needed in general, should we write up a JEP to support them explicitly?

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PR Review Comment: https://git.openjdk.org/jdk/pull/27614#discussion_r2583145498