"number_of_shards" : "5",
        "number_of_replicas" : "1",
        "uuid" : "5fluDb3PStuKaHkl-5gdNw",
        "version" : {
          "created" : "6000051"
        },
        "provided_name" : "fess_config.file_config"
      }
    }
  }

    private static final int SIGNATURE_LENGTH = 16;

    @BeforeAll
    static void setupClass() {
        // Ensure BouncyCastle provider is available for AES-CMAC
        if (Security.getProvider(BouncyCastleProvider.PROVIDER_NAME) == null) {
            Security.addProvider(new BouncyCastleProvider());
        }
    }

    @BeforeEach
    void setup() {
        sessionKey = new byte[16];
        Arrays.fill(sessionKey, (byte) 0xAA);