Org.BouncyCastle.Math.BigInteger.BigInteger C# (CSharp) Method

		public BigInteger(
			int		bitLength,
			int		certainty,
			Random	random)
		{
			if (bitLength < 2)
				throw new ArithmeticException("bitLength < 2");

			this.sign = 1;
			this.nBitLength = bitLength;

			if (bitLength == 2)
			{
				this.magnitude = random.Next(2) == 0
					?	Two.magnitude
					:	Three.magnitude;
				return;
			}

			int nBytes = GetByteLength(bitLength);
			byte[] b = new byte[nBytes];

			int xBits = BitsPerByte * nBytes - bitLength;
			byte mask = rndMask[xBits];

			for (;;)
			{
				random.NextBytes(b);

				// strip off any excess bits in the MSB
				b[0] &= mask;

				// ensure the leading bit is 1 (to meet the strength requirement)
				b[0] |= (byte)(1 << (7 - xBits));

				// ensure the trailing bit is 1 (i.e. must be odd)
				b[nBytes - 1] |= 1;

				this.magnitude = MakeMagnitude(b, 0, b.Length);
				this.nBits = -1;
				this.mQuote = -1L;

				if (certainty < 1)
					break;

				if (CheckProbablePrime(certainty, random))
					break;

				if (bitLength > 32)
				{
					for (int rep = 0; rep < 10000; ++rep)
					{
						int n = 33 + random.Next(bitLength - 2);
						this.magnitude[this.magnitude.Length - (n >> 5)] ^= (1 << (n & 31));
						this.magnitude[this.magnitude.Length - 1] ^= ((random.Next() + 1) << 1);
						this.mQuote = -1L;

						if (CheckProbablePrime(certainty, random))
							return;
					}
				}
			}
		}