Feature Request: Add 25519MLKEM768 Support to Minicrypto Backend

[Ye1v]

Thank you for your great work on picotls!

I would like to request support for the 25519MLKEM768 post-quantum key exchange algorithm in the minicrypto backend.

Background and Motivation

With the growing demand for post-quantum cryptography, 25519MLKEM768 is gaining popularity as a hybrid key exchange mechanism. Support for this in the minicrypto engine would allow picotls to be used in more post-quantum and hybrid scenarios, especially where a lightweight crypto backend is required.

Request

• Please consider adding 25519MLKEM768 (or compatible post-quantum KEMs) to the minicrypto binding.

[kazuho]

I agree that it would be a nice have. For context, we already have support for 25519MLKEM768 in the OpenSSL backend, but in some deployments it makes sense to use a smaller crypto library.