public static Task <bool> IsPrime(this BigInteger source, IPrimalityTest primalityTest)
{
if (source == null)
{
throw new ArgumentNullException(nameof(source));
}
if (primalityTest == null)
{
throw new ArgumentNullException(nameof(primalityTest));
}
return(primalityTest.TestAsync(source));
}
public static async Task <BigInteger> GeneratePrime(uint bitLength, IRandomProvider randomProvider, IPrimalityTest primalityTest)
{
if (randomProvider == null)
{
throw new ArgumentNullException(nameof(randomProvider));
}
if (bitLength < 8)
{
throw new ArgumentOutOfRangeException(nameof(bitLength), "Bit length must be at least of length 8.");
}
var bytes = bitLength / 8;
var randomNumberBytes = new byte[bytes];
randomProvider.NextBytes(randomNumberBytes);
var result = new BigInteger(randomNumberBytes);
if (result.Sign < 0)
{
result = BigInteger.Negate(result);
}
if (result.IsEven)
{
result = result + 1;
}
while (!await primalityTest.TestAsync(result))
{
result = result + 2;
}
return(result);
}