| package org.bouncycastle.jcajce.provider.asymmetric.dsa; |
| |
| import java.security.AlgorithmParameters; |
| import java.security.InvalidAlgorithmParameterException; |
| import java.security.InvalidParameterException; |
| import java.security.SecureRandom; |
| import java.security.spec.AlgorithmParameterSpec; |
| import java.security.spec.DSAParameterSpec; |
| |
| import org.bouncycastle.crypto.digests.SHA256Digest; |
| import org.bouncycastle.crypto.generators.DSAParametersGenerator; |
| import org.bouncycastle.crypto.params.DSAParameterGenerationParameters; |
| import org.bouncycastle.crypto.params.DSAParameters; |
| import org.bouncycastle.jcajce.provider.asymmetric.util.BaseAlgorithmParameterGeneratorSpi; |
| |
| public class AlgorithmParameterGeneratorSpi |
| extends BaseAlgorithmParameterGeneratorSpi |
| { |
| protected SecureRandom random; |
| protected int strength = 1024; |
| protected DSAParameterGenerationParameters params; |
| |
| protected void engineInit( |
| int strength, |
| SecureRandom random) |
| { |
| if (strength < 512 || strength > 3072) |
| { |
| throw new InvalidParameterException("strength must be from 512 - 3072"); |
| } |
| |
| if (strength <= 1024 && strength % 64 != 0) |
| { |
| throw new InvalidParameterException("strength must be a multiple of 64 below 1024 bits."); |
| } |
| |
| if (strength > 1024 && strength % 1024 != 0) |
| { |
| throw new InvalidParameterException("strength must be a multiple of 1024 above 1024 bits."); |
| } |
| |
| this.strength = strength; |
| this.random = random; |
| } |
| |
| protected void engineInit( |
| AlgorithmParameterSpec genParamSpec, |
| SecureRandom random) |
| throws InvalidAlgorithmParameterException |
| { |
| throw new InvalidAlgorithmParameterException("No supported AlgorithmParameterSpec for DSA parameter generation."); |
| } |
| |
| protected AlgorithmParameters engineGenerateParameters() |
| { |
| DSAParametersGenerator pGen; |
| |
| if (strength <= 1024) |
| { |
| pGen = new DSAParametersGenerator(); |
| } |
| else |
| { |
| pGen = new DSAParametersGenerator(new SHA256Digest()); |
| } |
| |
| if (random == null) |
| { |
| random = new SecureRandom(); |
| } |
| |
| if (strength == 1024) |
| { |
| params = new DSAParameterGenerationParameters(1024, 160, 80, random); |
| pGen.init(params); |
| } |
| else if (strength > 1024) |
| { |
| params = new DSAParameterGenerationParameters(strength, 256, 80, random); |
| pGen.init(params); |
| } |
| else |
| { |
| pGen.init(strength, 20, random); |
| } |
| |
| DSAParameters p = pGen.generateParameters(); |
| |
| AlgorithmParameters params; |
| |
| try |
| { |
| params = createParametersInstance("DSA"); |
| params.init(new DSAParameterSpec(p.getP(), p.getQ(), p.getG())); |
| } |
| catch (Exception e) |
| { |
| throw new RuntimeException(e.getMessage()); |
| } |
| |
| return params; |
| } |
| } |