fix: add support for generating MLDSA-44 and MLDSA-65 keys (#37)

Author: vikram-gaur

src/com/google/cose/CoseKey.java

@@ -132,6 +132,8 @@ public static CoseKey generateKey(Algorithm algorithm) throws CborException, Cos
     switch (algorithm) {
       case SIGNING_ALGORITHM_EDDSA:
         return OkpSigningKey.generateKey();
+      case SIGNING_ALGORITHM_MLDSA_44:
+      case SIGNING_ALGORITHM_MLDSA_65:
       case SIGNING_ALGORITHM_MLDSA_87:
         return AkpSigningKey.generateKey(algorithm, AkpKey.CONSCRYPT_PROVIDER);
       case SIGNING_ALGORITHM_ECDSA_SHA_256:

src/com/google/cose/utils/CoseUtils.java

@@ -331,7 +331,7 @@ public static void verifyCoseSign1Message(CoseKey key, Sign1Message message,
       ((AkpSigningKey) key)
           .verify(algorithm, encodedStructure, message.getSignature(), AkpKey.CONSCRYPT_PROVIDER);
     } else {
-      new CoseException("Incompatible key used.");
+      throw new CoseException("Incompatible key used.");
     }
   }