@Override
  public DeterministicAead getPrimitive(ByteString serializedKey) throws GeneralSecurityException {
    try {
      AesSivKey keyProto =
          AesSivKey.parseFrom(serializedKey, ExtensionRegistryLite.getEmptyRegistry());
      validateKey(keyProto);
      return new AesSiv(keyProto.getKeyValue().toByteArray());
    } catch (InvalidProtocolBufferException e) {
      throw new GeneralSecurityException("Expected serialized AesSivKey proto", e);
    }
  }
Custom type url that this manager does support.
java_src/src/main/java/com/google/crypto/tink/daead/internal/testing/LegacyAesSivTestKeyManager.java