We used to have three problems:
- overuse of the <Sha256 as Digest>::OutputSize, which is just, well, U32. Sometimes used as a parameter (as in generate_oprf1), sometimes as a constant (as in generate_oprf3).
- the `hash_to_curve` operation for `RistrettoPoint` which requires 64 bits of input entropy, is fed 64 bits of which the last 32 are zero,
- the `hash_to_curve` operation for `Curve25519Point` which requires 32 bits of input entropy, is fed 64 bits of which the last 32 are discarded,
This corrects all three and uses U32 where the size of the digest is not meant to be a constraint.
Addresses #15 partially.
This brings the `Group` and `SizedBytes` traits into some sort of name
coherence (they both return a GenericArray). This also uses
`&my_generic_array[..]` (i.e. the `Deref` impl) over
`my_generic_array.as_slice()`.
This is useful for getting serialization of the KEXState, KEXMessage formats without too much boilerplate
Add client_login, login_first_message roundtrip serialization tests
François Garillot