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);
}