BigInteger.genCoPrime C# (CSharp) Method

        public BigInteger genCoPrime(int bits, Random rand)
        {
	        bool done = false;
	        BigInteger result = new BigInteger();

	        while(!done)
	        {
	                result.genRandomBits(bits, rand);
	                //Console.WriteLine(result.ToString(16));

		        // gcd test
		        BigInteger g = result.gcd(this);
			if(g.dataLength == 1 && g.data[0] == 1)
                                done = true;
	        }

	        return result;
        }

        public void TestGenCoPrime()
        {
            { // Test small values
                var bi  = new BigInteger();
                var rng = new RNGCryptoServiceProvider();

                bi.genRandomBits(100, rng);

                var coprime = bi.genCoPrime(10, rng);

                Assert.IsTrue((bi.gcd(coprime)).getBytes()[0] == 1);
            }

            { // Test arbitrary values
                var bi   = new BigInteger();
                var rng  = new RNGCryptoServiceProvider();
                var rand = new Random();

                bi.genRandomBits(rand.Next(2241), rng);

                var coprime = bi.genCoPrime(rand.Next(2241), rng);

                Assert.IsTrue((bi.gcd(coprime)).getBytes()[0] == 1);
            }
        }