Org.BouncyCastle.Crypto.Engines.IdeaEngine.Mul C# (CSharp) Method

        private int Mul(
            int x,
            int y)
        {
            if (x == 0)
            {
                x = (BASE - y);
            }
            else if (y == 0)
            {
                x = (BASE - x);
            }
            else
            {
                int     p = x * y;
                y = p & MASK;
                x = (int) ((uint) p >> 16);
                x = y - x + ((y < x) ? 1 : 0);
            }
            return x & MASK;
        }
        private void IdeaFunc(