Support SM2/SM3 algorithms

[SunFulong]

SM2/SM3 are Chinese cryptographic algorithms: SM3 (hash function) and SM2 (public-private key cryptography), widely used in China, will you support them?

[martinthomson]

@SunFulong Does this relate to the message signatures specification or something else? (SM3 might apply to digest, say.)

[SunFulong]

Yes, SM2 is a public key cryptographic algorithm that based on elliptic curves, signature is part of it.

[martinthomson]

@SunFulong my question was about which specification you are referring to. There are multiple specifications in this repository. I doubt that this applies to the retrofit work, for example.

If your goal is to request the addition of SM3 and SM2 to a particular specification, we need to know which. If this is a more general inquiry, then our mailing list is probably a better place to start.