Normalize generic parameters for LoginSecondMessage

(aka use the CipherSuite just like the others)

Repair the generics in KE trait: it makes sense that generate_ke[1-3] should operate on the same key representation.

src/key_exchange/traits.rs

@@ -12,19 +12,19 @@ use rand_core::{CryptoRng, RngCore};
 
 use std::convert::TryFrom;
 
-pub trait KeyExchange<D: Hash> {
+pub trait KeyExchange<D: Hash, KeyFormat: KeyPair<Repr = Key>> {
     type KE1State: TryFrom<Vec<u8>, Error = InternalPakeError> + ToBytes;
     type KE2State: TryFrom<Vec<u8>, Error = ProtocolError> + ToBytes;
     type KE1Message: TryFrom<Vec<u8>, Error = InternalPakeError> + ToBytes;
     type KE2Message: TryFrom<Vec<u8>, Error = ProtocolError> + ToBytes;
     type KE3Message: TryFrom<Vec<u8>, Error = ProtocolError> + ToBytes;
 
-    fn generate_ke1<R: RngCore + CryptoRng, KeyFormat: KeyPair<Repr = Key>>(
+    fn generate_ke1<R: RngCore + CryptoRng>(
         l1_component: Vec<u8>,
         rng: &mut R,
     ) -> Result<(Self::KE1State, Self::KE1Message), ProtocolError>;
 
-    fn generate_ke2<R: RngCore + CryptoRng, KeyFormat: KeyPair<Repr = Key>>(
+    fn generate_ke2<R: RngCore + CryptoRng>(
         rng: &mut R,
         l1_bytes: Vec<u8>,
         l2_bytes: Vec<u8>,
@@ -33,7 +33,7 @@ pub trait KeyExchange<D: Hash> {
         server_s_sk: KeyFormat::Repr,
     ) -> Result<(Self::KE2State, Self::KE2Message), ProtocolError>;
 
-    fn generate_ke3<KeyFormat: KeyPair<Repr = Key>>(
+    fn generate_ke3(
         l2_component: Vec<u8>,
         ke2_message: Self::KE2Message,
         ke1_state: &Self::KE1State,

src/key_exchange/tripledh.rs

@@ -31,14 +31,14 @@ static STR_3DH: &[u8] = b"3DH keys";
 /// The Triple Diffie-Hellman key exchange implementation
 pub struct TripleDH;
 
-impl<D: Hash> KeyExchange<D> for TripleDH {
+impl<D: Hash, KeyFormat: KeyPair<Repr = Key>> KeyExchange<D, KeyFormat> for TripleDH {
     type KE1State = KE1State<<D as FixedOutput>::OutputSize>;
     type KE2State = KE2State<<D as FixedOutput>::OutputSize>;
     type KE1Message = KE1Message;
     type KE2Message = KE2Message<<D as FixedOutput>::OutputSize>;
     type KE3Message = KE3Message<<D as FixedOutput>::OutputSize>;
 
-    fn generate_ke1<R: RngCore + CryptoRng, KeyFormat: KeyPair<Repr = Key>>(
+    fn generate_ke1<R: RngCore + CryptoRng>(
         l1_component: Vec<u8>,
         rng: &mut R,
     ) -> Result<(Self::KE1State, Self::KE1Message), ProtocolError> {
@@ -69,7 +69,7 @@ impl<D: Hash> KeyExchange<D> for TripleDH {
         ))
     }
 
-    fn generate_ke2<R: RngCore + CryptoRng, KeyFormat: KeyPair<Repr = Key>>(
+    fn generate_ke2<R: RngCore + CryptoRng>(
         rng: &mut R,
         l1_bytes: Vec<u8>,
         l2_bytes: Vec<u8>,
@@ -132,7 +132,7 @@ impl<D: Hash> KeyExchange<D> for TripleDH {
         ))
     }
 
-    fn generate_ke3<KeyFormat: KeyPair<Repr = Key>>(
+    fn generate_ke3(
         l2_component: Vec<u8>,
         ke2_message: Self::KE2Message,
         ke1_state: &Self::KE1State,