obfuscates a file using 1-byte xor

filexor.cs

static void xorFile(string inputFilename, string outputFilename, byte xorValue)
{
    const int CHUNK_SIZE = 4096;
    using (FileStream inputStream = new FileStream(inputFilename, FileMode.Open, FileAccess.Read))
    {
        BinaryReader binaryReader = new BinaryReader(inputStream, Encoding.ASCII);
        using (FileStream outputStream = new FileStream(outputFilename, FileMode.Create, FileAccess.Write))
        {
            BinaryWriter binaryWriter = new BinaryWriter(outputStream, Encoding.ASCII);
            byte[] chunk = binaryReader.ReadBytes(CHUNK_SIZE);
            while (chunk.Length > 0)
            {
                for (int i = 0; i < chunk.Length; i++)
                {
                    chunk[i] ^= xorValue;
                }
                binaryWriter.Write(chunk);
                chunk = binaryReader.ReadBytes(CHUNK_SIZE);
            }
        }
    }
}