package org.bouncycastle.jcajce.provider.asymmetric.elgamal;
import java.security.AlgorithmParameters;
import java.security.InvalidAlgorithmParameterException;
import java.security.SecureRandom;
import java.security.spec.AlgorithmParameterSpec;
import javax.crypto.spec.DHGenParameterSpec;
import javax.crypto.spec.DHParameterSpec;
import org.bouncycastle.crypto.generators.ElGamalParametersGenerator;
import org.bouncycastle.crypto.params.ElGamalParameters;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
public class AlgorithmParameterGeneratorSpi
extends java.security.AlgorithmParameterGeneratorSpi
{
protected SecureRandom random;
protected int strength = 1024;
private int l = 0;
protected void engineInit(
int strength,
SecureRandom random)
{
this.strength = strength;
this.random = random;
}
protected void engineInit(
AlgorithmParameterSpec genParamSpec,
SecureRandom random)
throws InvalidAlgorithmParameterException
{
if (!(genParamSpec instanceof DHGenParameterSpec))
{
throw new InvalidAlgorithmParameterException("DH parameter generator requires a DHGenParameterSpec for initialisation");
}
DHGenParameterSpec spec = (DHGenParameterSpec)genParamSpec;
this.strength = spec.getPrimeSize();
this.l = spec.getExponentSize();
this.random = random;
}
protected AlgorithmParameters engineGenerateParameters()
{
ElGamalParametersGenerator pGen = new ElGamalParametersGenerator();
if (random != null)
{
pGen.init(strength, 20, random);
}
else
{
pGen.init(strength, 20, new SecureRandom());
}
ElGamalParameters p = pGen.generateParameters();
AlgorithmParameters params;
try
{
params = AlgorithmParameters.getInstance("ElGamal", BouncyCastleProvider.PROVIDER_NAME);
params.init(new DHParameterSpec(p.getP(), p.getG(), l));
}
catch (Exception e)
{
throw new RuntimeException(e.getMessage());
}
return params;
}
}