[Feature Request] - add mlkem768nistp256-sha256 and mlkem1024nistp384-sha384 KEX methods to OpenSSH

[hd-hd]

Is your feature request related to a problem? Please describe.

Amazon Linux 2023's OpenSSH currently supports the upstream OpenSSH post-quantum key exchange algorithms, namely:

• sntrup761x25519-sha512
• sntrup761x25519-sha512@openssh.com
• mlkem768x25519-sha256

However, it does not provide these FIPS-compatible ML-KEM/NISTP hybrid key exchange algorithms:

• mlkem768nistp256-sha256
• mlkem1024nistp384-sha384

These algorithms would be useful for environments that need post-quantum FIPS-compatible key exchange algorithms. They also align with the recommendation described in Germany's BSI Technical Guideline TR-02102-4 v2026-01.

Describe the solution you'd like

Please consider applying the Red Hat OpenSSH patch that adds support for:

• mlkem768nistp256-sha256
• mlkem1024nistp384-sha384

Describe alternatives you've considered

None.

Additional context

The currently available KEX algorithms can be checked with:

ssh -Q kex