Use raw encodings for EDDSA Public Key ECPoint

[janklaussner]

Hey composite sigs authors, I just wanted to point out that I think the ASN.1 for EDDSA composites is wrong. It uses ECPoint for the SecondPublicKeytype, but EDDSA public keys aren't encoded using ECPoint, they are raw.

pk-MLDSA65-Ed25519-SHA512 PUBLIC-KEY ::= pk-CompositeSignature{ id-MLDSA65-Ed25519-SHA512, OCTET STRING, ECPoint} RFC 8410:

pk-Ed25519 PUBLIC-KEY ::= {
    IDENTIFIER id-Ed25519
    -- KEY no ASN.1 wrapping --
    PARAMS ARE absent
    CERT-KEY-USAGE {digitalSignature, nonRepudiation,
                    keyCertSign, cRLSign}
    PRIVATE-KEY CurvePrivateKey
}

So however you do the encoding for the ML-DSA keys is how you should do the encoding for EDDSA keys as well.

Daniel

[janklaussner]

done with #47