public override byte[] ProcessBytes(
byte[] input,
int inOff,
int length)
{
if (length < 1)
return null;
if (input == null)
throw new ArgumentNullException("input");
if (bufOff + length > buffer.Length)
throw new DataLengthException("attempt to process message to long for cipher");
Array.Copy(input, inOff, buffer, bufOff, length);
bufOff += length;
return null;
}