|
static private GenerateSafePrimes ( int size, int certainty, |
||
| size | int | |
| certainty | int | |
| random | ||
| return | Org.BouncyCastle.Math.BigInteger[] | |
/**
* which Generates the p and g values from the given parameters,
* returning the ElGamalParameters object.
* <p>
* Note: can take a while...
*/
public ElGamalParameters GenerateParameters()
{
//
// find a safe prime p where p = 2*q + 1, where p and q are prime.
//
BigInteger[] safePrimes = DHParametersHelper.GenerateSafePrimes(size, certainty, random);
BigInteger p = safePrimes[0];
BigInteger q = safePrimes[1];
BigInteger g;
int qLength = size - 1;
//
// calculate the generator g - the advantage of using the 2q+1
// approach is that we know the prime factorisation of (p - 1)...
//
do
{
g = new BigInteger(qLength, random);
}while (g.ModPow(BigInteger.Two, p).Equals(BigInteger.One) ||
g.ModPow(q, p).Equals(BigInteger.One));
return(new ElGamalParameters(p, g));
}
public virtual DHParameters GenerateParameters()
{
BigInteger[] array = DHParametersHelper.GenerateSafePrimes(size, certainty, random);
BigInteger p = array[0];
BigInteger q = array[1];
BigInteger g = DHParametersHelper.SelectGenerator(p, q, random);
return(new DHParameters(p, g, q, BigInteger.Two, null));
}
public ElGamalParameters GenerateParameters()
{
BigInteger[] array = DHParametersHelper.GenerateSafePrimes(this.size, this.certainty, this.random);
BigInteger p = array[0];
BigInteger q = array[1];
BigInteger g = DHParametersHelper.SelectGenerator(p, q, this.random);
return(new ElGamalParameters(p, g));
}
/**
* which Generates the p and g values from the given parameters,
* returning the ElGamalParameters object.
* <p>
* Note: can take a while...
* </p>
*/
public ElGamalParameters GenerateParameters()
{
//
// find a safe prime p where p = 2*q + 1, where p and q are prime.
//
BigInteger[] safePrimes = DHParametersHelper.GenerateSafePrimes(size, certainty, random);
BigInteger p = safePrimes[0];
BigInteger q = safePrimes[1];
BigInteger g = DHParametersHelper.SelectGenerator(p, q, random);
return(new ElGamalParameters(p, g));
}
/**
* which Generates the p and g values from the given parameters,
* returning the DHParameters object.
* <p>
* Note: can take a while...</p>
*/
public virtual DHParameters GenerateParameters()
{
//
// find a safe prime p where p = 2*q + 1, where p and q are prime.
//
IBigInteger[] safePrimes = DHParametersHelper.GenerateSafePrimes(size, certainty, random);
IBigInteger p = safePrimes[0];
IBigInteger q = safePrimes[1];
IBigInteger g = DHParametersHelper.SelectGenerator(p, q, random);
return(new DHParameters(p, g, q, BigInteger.Two, null));
}
