public void Init(byte[] x)
 {
     this.x = GcmUtilities.AsUints(x);
 }
        public void Init(byte[] H)
        {
            if (M == null)
            {
                M = new uint[32][][];
            }
            else if (Arrays.AreEqual(this.H, H))
            {
                return;
            }

            this.H = Arrays.Clone(H);

            M[0]    = new uint[16][];
            M[1]    = new uint[16][];
            M[0][0] = new uint[4];
            M[1][0] = new uint[4];
            M[1][8] = GcmUtilities.AsUints(H);

            for (int j = 4; j >= 1; j >>= 1)
            {
                uint[] tmp = (uint[])M[1][j + j].Clone();
                GcmUtilities.MultiplyP(tmp);
                M[1][j] = tmp;
            }

            {
                uint[] tmp = (uint[])M[1][1].Clone();
                GcmUtilities.MultiplyP(tmp);
                M[0][8] = tmp;
            }

            for (int j = 4; j >= 1; j >>= 1)
            {
                uint[] tmp = (uint[])M[0][j + j].Clone();
                GcmUtilities.MultiplyP(tmp);
                M[0][j] = tmp;
            }

            for (int i = 0; ;)
            {
                for (int j = 2; j < 16; j += j)
                {
                    for (int k = 1; k < j; ++k)
                    {
                        uint[] tmp = (uint[])M[i][j].Clone();
                        GcmUtilities.Xor(tmp, M[i][k]);
                        M[i][j + k] = tmp;
                    }
                }

                if (++i == 32)
                {
                    return;
                }

                if (i > 1)
                {
                    M[i]    = new uint[16][];
                    M[i][0] = new uint[4];
                    for (int j = 8; j > 0; j >>= 1)
                    {
                        uint[] tmp = (uint[])M[i - 2][j].Clone();
                        GcmUtilities.MultiplyP8(tmp);
                        M[i][j] = tmp;
                    }
                }
            }
        }