RFR: 8314323: TLS 1.3 Hybrid Key Exchange

[Jamil Nimeh]

On Fri, 3 Oct 2025 17:20:32 GMT, Bernd <duke 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.
>
> src/java.base/share/classes/sun/security/ssl/NamedGroup.java line 802:
> 
>> 800:                         FFDHE_3072,
>> 801:                         FFDHE_4096,
>> 802:                         FFDHE_6144,
> 
> Unrelated change?

No, the choise to knock out ffdhe6144 and 8192 from the default list was done on purpose.  I don't think they get much use and they can always be re-enabled via SSLParameters or the system property.  We're open to feedback on this if you or others feel like they should remain in place, though.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27614#discussion_r2402940752