if (!initialised) { throw new IllegalStateException("Null engine not initialised"); }
    public int processBlock(byte[] in, int inOff, byte[] out, int outOff)        throws DataLengthException, IllegalStateException    {            if ((inOff + BLOCK_SIZE) > in.length)            {                throw new DataLengthException("input buffer too short");            }            if ((outOff + BLOCK_SIZE) > out.length)            {                throw new DataLengthException("output buffer too short");            }                        for (int i = 0; i < BLOCK_SIZE; ++i)            {                out[outOff + i] = in[inOff + i];            }                        return BLOCK_SIZE;    }