Create Binary stream of file

FileStream fileStream;
            byte[] fileByte;
            using (fileStream = File.OpenRead(filePath))
            {
                fileByte = new byte[fileStream.Length];
                ReadWholeArray(fileStream, fileByte);
            }
            return fileByte;

private static void ReadWholeArray(Stream stream, byte[] data)
        {
            int offset = 0;
            int remaining = data.Length;
            while (remaining > 0)
            {
                int read = stream.Read(data, offset, remaining);
                if (read <= 0)
                {
                    throw new EndOfStreamException(String.Format("{0}:End of stream reached with {1} bytes left to read", "Generate binary stream", remaining));
                }

                remaining -= read;
                offset += read;
            }
        }