public static byte[] ComputeAdditionalData(long fileLength) { long chunkCount = Utilities.RoundUp(fileLength, Constants.FileChunkSize); byte[] ciphertextLength = BitConverter.GetBytes(chunkCount * Constants.TotalChunkLength); return(Utilities.ConcatArrays(Constants.KryptorMagicBytes, Constants.EncryptionVersion, ciphertextLength)); }