avt.DynamicFlashRotator.Net.RegCore.Cryptography.BigInteger.genRandomBits C# (CSharp) Method

        public void genRandomBits(int bits, Random rand)
        {
            int dwords = bits >> 5;
            int remBits = bits & 0x1F;

            if (remBits != 0)
                dwords++;

            if (dwords > maxLength)
                throw (new ArithmeticException("Number of required bits > maxLength."));

            for (int i = 0; i < dwords; i++)
                data[i] = (uint)(rand.NextDouble() * 0x100000000);

            for (int i = dwords; i < maxLength; i++)
                data[i] = 0;

            if (remBits != 0) {
                uint mask = (uint)(0x01 << (remBits - 1));
                data[dwords - 1] |= mask;

                mask = (uint)(0xFFFFFFFF >> (32 - remBits));
                data[dwords - 1] &= mask;
            } else
                data[dwords - 1] |= 0x80000000;

            dataLength = dwords;

            if (dataLength == 0)
                dataLength = 1;
        }

        //***********************************************************************
        // Tests the correct implementation of sqrt() method.
        //***********************************************************************

        public static void SqrtTest(int rounds)
        {
            Random rand = new Random();
            for (int count = 0; count < rounds; count++) {
                // generate data of random length
                int t1 = 0;
                while (t1 == 0)
                    t1 = (int)(rand.NextDouble() * 1024);

                Console.Write("Round = " + count);

                BigInteger a = new BigInteger();
                a.genRandomBits(t1, rand);

                BigInteger b = a.sqrt();
                BigInteger c = (b + 1) * (b + 1);

                // check that b is the largest integer such that b*b <= a
                if (c <= a) {
                    Console.WriteLine("\nError at round " + count);
                    Console.WriteLine(a + "\n");
                    return;
                }
                Console.WriteLine(" <PASSED>.");
            }
        }