remove the last few constants

src/opaque.rs

@@ -15,7 +15,7 @@ use crate::{
     keypair::{KeyPair, SizedBytes},
     oprf,
     oprf::OprfClientBytes,
-    serialization::{serialize, tokenize, ProtocolMessageType},
+    serialization::{serialize, tokenize, CredentialType, ProtocolMessageType},
     slow_hash::SlowHash,
 };
 use generic_array::{typenum::Unsigned, GenericArray};
@@ -23,9 +23,6 @@ use rand_core::{CryptoRng, RngCore};
 use std::{convert::TryFrom, marker::PhantomData};
 use zeroize::Zeroize;
 
-const CREDENTIAL_TYPE_SKU: u8 = 0x01;
-const CREDENTIAL_TYPE_PKS: u8 = 0x03;
-
 // Messages
 // =========
 
@@ -136,8 +133,8 @@ where
         registration_response.extend_from_slice(&serialize(Vec::new(), 2));
 
         // TODO: The following should not be hardcoded, but instead be customizable
-        registration_response.extend_from_slice(&serialize(vec![CREDENTIAL_TYPE_SKU], 1));
+        registration_response.extend_from_slice(&[1u8, CredentialType::SkU as u8 + 1]);
-        registration_response.extend_from_slice(&serialize(vec![CREDENTIAL_TYPE_PKS], 1));
+        registration_response.extend_from_slice(&[1u8, CredentialType::PkS as u8 + 1]);
 
         let mut output: Vec<u8> = Vec::new();
         output.push(ProtocolMessageType::from(self) as u8 + 1);

src/serialization/mod.rs

@@ -22,6 +22,7 @@ pub enum ProtocolMessageType {
     CredentialResponse,
 }
 
+#[allow(dead_code)]
 pub enum CredentialType {
     SkU,
     PkU,