private static BigInteger GenKey(GeneratorWrap gen, BigInteger modulus)
{
var key = gen.GetBig() % modulus;
while (!KeyCheck(key, modulus))
{
key = gen.GetBig() % modulus;
}
return(key);
}
/// <summary>
/// Customizable version with full NewKey parameters.
/// </summary>
/// <param name="wordSize">number of byte of the key</param>
/// <param name="testPrecision">percision of the test, error = 1/2^precision</param>
/// <param name="primePrecision">percision of primality test, error = 1/2^(2*precision)</param>
/// <param name="generator">random number generator, it is not disposed</param>
/// <param name="threads">number of threads to use</param>
/// <returns>result of the test</returns>
public static bool CustomTest(uint wordSize, uint testPrecision, uint primePrecision,
RandomNumberGenerator generator, int threads = 1)
{
if (wordSize < 128 || testPrecision < 1)
{
throw new ArgumentNullException("FiatShamirIdentification test invalid input\n");
}
uint iteration = 0;
bool choice;
BigInteger number;
var result = true;
var priv = PrivateKey.NewKey(generator, wordSize, threads, primePrecision);
var pub = priv.GetPublicKey();
var verifier = pub.GetVerifier();
var proover = priv.GetProover(generator);
//test with key
while (iteration < testPrecision && result)
{
number = proover.Step1();
choice = verifier.Step1(ref number);
number = proover.Step2(choice);
verifier.Step2(number);
result = verifier.CheckState();
iteration++;
}
if (!result) //if not verified, fail
{
return(false);
}
//test without key
var genwrap = new GeneratorWrap(generator, wordSize);
var falseKey = new PrivateKey(genwrap.GetBig(), genwrap.GetBig(), wordSize);
proover = new Proover(falseKey, generator);
iteration = 0;
while (iteration < testPrecision && result)
{
number = proover.Step1();
choice = verifier.Step1(ref number);
number = proover.Step2(choice);
verifier.Step2(number);
result = verifier.CheckState();
iteration++;
}
return(!result);
}
//Generates the modulus using one thread
private static BigInteger SeqGenMod(GeneratorWrap gen, uint wordSize, uint precision)
{
IPrime generator = new SequentialPrime(gen.GetInt(), precision, wordSize);
var firstPrime = gen.GetBig();
var secondPrime = gen.GetBig();
while (!SecurityCheck(firstPrime, secondPrime))
{
secondPrime = gen.GetBig();
}
firstPrime = generator.NextPrime(firstPrime);
secondPrime = generator.NextPrime(secondPrime);
return(firstPrime * secondPrime);
}
/// <summary>
/// Start the protocol and return the init for Verifier.Step1.
/// </summary>
/// <returns>number to send to Verifier</returns>
public BigInteger Step1()
{
_synch = true;
_sessionNumber = _generator.GetBig() % _key.Modulus;
var square = _sessionNumber * _sessionNumber;
var squareMod = square % _key.Modulus;
//avoid comunication of the key
while (_sessionNumber < 3 && 1 != BigInteger.GreatestCommonDivisor(_sessionNumber, _key.Modulus) &&
1 != BigInteger.GreatestCommonDivisor(squareMod, _key.Modulus) && square == squareMod)
{
_sessionNumber = _generator.GetBig() % _key.Modulus;
square = _sessionNumber * _sessionNumber;
squareMod = square % _key.Modulus;
}
return(squareMod);
}
//Generates the modulus using more thread
private static BigInteger ParGenMod(GeneratorWrap gen, uint wordSize, int threads, uint precision)
{
IPrime mainGenerator, workerGenerator;
//threads distribution for primes creation
if (threads < 4)
{
mainGenerator = new SequentialPrime(gen.GetInt(), precision, wordSize);
workerGenerator = new SequentialPrime(gen.GetInt(), precision, wordSize);
}
else
{
mainGenerator = new ParallelPrime(gen.GetInt(), precision, wordSize, threads - threads / 2);
workerGenerator = new ParallelPrime(gen.GetInt(), precision, wordSize, threads / 2);
}
//primes creation
var firstPrime = gen.GetBig();
var secondPrime = gen.GetBig();
while (!SecurityCheck(firstPrime, secondPrime))
{
secondPrime = gen.GetBig();
}
var worker = new Task <BigInteger>(() => workerGenerator.NextPrime(firstPrime));
worker.Start();
secondPrime = mainGenerator.NextPrime(secondPrime);
worker.Wait();
firstPrime = worker.Result;
worker.Dispose();
return(firstPrime * secondPrime);
}