byte[] server = hex("0102030405060708");
        byte[] clientChallenge = hex("0102030405060708");
        long nanos1601 = 0x1122334455667788L;
        byte[] avPairs = hex("A1A2A3A4");

        // Manually build the expected NTLMv2 blob (same as production code)
        int avPairsLength = avPairs.length;
        byte[] blob = new byte[28 + avPairsLength + 4];