Add support for EdDSA (Ed25519 and Ed448)

[AlexLaroche]

[mlindgren]

Hi AlexLaroche, historically Microsoft has disallowed the use of EdDSA in our products because it was not a FIPS-approved algorithm. As of 2023, EdDSA is now FIPS approved, but we're now in the process of implementing and adopting PQC algorithms such as ML-DSA, so it remains a low priority for us. As such, I do not expect that we'll implement EdDSA any time soon, if ever.

[AlexLaroche]

I understand that priority is given to the implementation of post-quantum algorithms.

At the same time, traditional cryptography is here to stay for a while since there is no consensus on how to make the transition between different countries.

Hybrids required: BSI (Germany), ANSSI (France)
Hybrids allowed: ENISA (EU), ETSI
Hybrids discouraged: NSA (US), NCSC (UK), CSE (Canada)

In this context, hybridization is at my opinion the best option considering the lack of history of post quantum algorithms in general (except LMS and XMSS).

The case of SIKE is a good example of the lack of perspective on the new post quantum algorithms. (It was a round 4 candidate.)

Are there any plans to implement at least X25519 which is considered in several TLS 1.3 hybridization ciphersuites and used in X-Wing?

[samuel-lee-msft]

X25519 is already supported with SymCryptEcDhSecretAgreement (using SymCryptEcurveParamsCurve25519)