Encryption is corrupting BMP files but not jpeg files

Question

My decryption code is, for some strange reason, cutting off the last few bits:

Why is this happening? Have I forgotten some code, or am I making some naïve mistake?

private static int chunkSize = 1048576;
public void Decrypt(string Input, string passPhrase, string sender)
{
    for (long i = 0; i < fsInput.Length; i += chunkSize)
    {
        byte[] chunkData = new byte[chunkSize];
        int bytesRead = 0;
        while ((bytesRead = fsInput.Read(chunkData, 0, chunkSize)) > 0)
        {
            cryptoStream.Write(chunkData, 0, bytesRead);
        }
    }
}

Answer 1

I was missing cryptoStream.FlushFinalBlock(); from the decrypt method