private static void AddExtraDataAES(ZipEntry entry, ZipExtraData extraData)
        {
            // Vendor Version: AE-1 IS 1. AE-2 is 2. With AE-2 no CRC is required and 0 is stored.
            const int VENDOR_VERSION = 2;
            // Vendor ID is the two ASCII characters "AE".
            const int VENDOR_ID = 0x4541;             //not 6965;

            extraData.StartNewEntry();
            // Pack AES extra data field see http://www.winzip.com/aes_info.htm
            //extraData.AddLeShort(7);							// Data size (currently 7)
            extraData.AddLeShort(VENDOR_VERSION);                           // 2 = AE-2
            extraData.AddLeShort(VENDOR_ID);                                // "AE"
            extraData.AddData(entry.AESEncryptionStrength);                 //  1 = 128, 2 = 192, 3 = 256
            extraData.AddLeShort((int)entry.CompressionMethod);             // The actual compression method used to compress the file
            extraData.AddNewEntry(0x9901);
        }