Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.DSAParams;
import java.security.interfaces.DSAPrivateKey;
import java.security.interfaces.DSAPublicKey;
import java.security.spec.DSAPrivateKeySpec;
import java.security.spec.DSAPublicKeySpec;
import java.security.spec.KeySpec;

public class Main {
    public static void main(String[] argv) throws Exception {
        KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
        keyGen.initialize(1024);
        KeyPair keypair = keyGen.genKeyPair();
        DSAPrivateKey privateKey = (DSAPrivateKey) keypair.getPrivate();
        DSAPublicKey publicKey = (DSAPublicKey) keypair.getPublic();

        DSAParams dsaParams = privateKey.getParams();
        BigInteger p = dsaParams.getP();
        BigInteger q = dsaParams.getQ();
        BigInteger g = dsaParams.getG();
        BigInteger x = privateKey.getX();
        BigInteger y = publicKey.getY();

        KeyFactory keyFactory = KeyFactory.getInstance("DSA");
        KeySpec publicKeySpec = new DSAPublicKeySpec(y, p, q, g);
        PublicKey publicKey1 = keyFactory.generatePublic(publicKeySpec);
        KeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
        PrivateKey privateKey1 = keyFactory.generatePrivate(privateKeySpec);

        byte[] buffer = new byte[1024];

        Signature sig = Signature.getInstance(privateKey1.getAlgorithm());
        sig.initSign(privateKey1);
        sig.update(buffer, 0, buffer.length);

        byte[] signature = sig.sign();

        sig = Signature.getInstance(publicKey1.getAlgorithm());
        sig.initVerify(publicKey1);
        sig.update(buffer, 0, buffer.length);
        sig.verify(signature);

    }
}