As a way to roll back the genericity, implement an extension trait of group for password-to-curve hashing,

This supersedes #18.

Co-authored-by: KevinLewi <[email protected]>

src/tests/opaque_ke_test.rs

@@ -23,7 +23,6 @@ use std::convert::TryFrom;
 
 struct X255193dhNoSlowHash;
 impl CipherSuite for X255193dhNoSlowHash {
-    type Digest = sha2::Sha256;
     type Group = EdwardsPoint;
     type KeyFormat = X25519KeyPair;
     type SlowHash = NoOpHash;
@@ -248,13 +247,14 @@ fn generate_parameters<CS: CipherSuite>() -> TestVectorParameters {
     )
     .unwrap();
     let r1_bytes = r1.to_bytes().to_vec();
-    let blinding_factor_bytes = *CS::Group::scalar_as_bytes(&client_registration.blinding_factor);
+    let blinding_factor_bytes =
+        CS::Group::scalar_as_bytes(&client_registration.blinding_factor).clone();
     let client_registration_state = client_registration.to_bytes().to_vec();
 
     let mut oprf_key_rng = CycleRng::new(oprf_key_raw.to_vec());
     let (r2, server_registration) = ServerRegistration::<CS>::start(r1, &mut oprf_key_rng).unwrap();
     let r2_bytes = r2.to_bytes().to_vec();
-    let oprf_key_bytes = *CS::Group::scalar_as_bytes(&server_registration.oprf_key);
+    let oprf_key_bytes = CS::Group::scalar_as_bytes(&server_registration.oprf_key).clone();
     let server_registration_state = server_registration.to_bytes().to_vec();
 
     let mut client_s_sk_and_nonce: Vec<u8> = Vec::new();

src/tests/serialization.rs

@@ -21,7 +21,6 @@ use std::convert::TryFrom;
 
 struct Default;
 impl CipherSuite for Default {
-    type Digest = sha2::Sha512;
     type Group = RistrettoPoint;
     type KeyFormat = crate::keypair::X25519KeyPair;
     type SlowHash = crate::slow_hash::NoOpHash;