generatekeypair.java

use bouncycastle to generate RSA keyPair

import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Security;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;

import org.bouncycastle.jce.provider.BouncyCastleProvider;

/**
 * @description generate asymmetrical key pair with algorithms, like RSA or DSA
 * @author Boris
 * @date 2009/04/08
 *
 */
public class GenerateKeyPair {
	
	private RSAPrivateKey priKey;
	private RSAPublicKey pubKey;
	
	public GenerateKeyPair(int keysize){
		
		Security.addProvider(new BouncyCastleProvider());
		KeyPairGenerator generator;
		try {
			generator = KeyPairGenerator.getInstance("RSA");
			generator.initialize(keysize);
			KeyPair keyPair = generator.generateKeyPair();
			priKey = (RSAPrivateKey)keyPair.getPrivate();
			pubKey = (RSAPublicKey)keyPair.getPublic();
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
					
	}
	
	/**
	 * @param keysize 512, 1024, 2048, 4096
	 * @param algorithm RSA or DSA
	 */
	public GenerateKeyPair(int keysize, String algorithm){
		Security.addProvider(new BouncyCastleProvider());
		KeyPairGenerator generator;
		try {
			generator = KeyPairGenerator.getInstance(algorithm);
			generator.initialize(keysize);
			KeyPair keyPair = generator.generateKeyPair();
			priKey = (RSAPrivateKey)keyPair.getPrivate();
			pubKey = (RSAPublicKey)keyPair.getPublic();
			
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
	}
	
	public PublicKey getPublicKey(){
		return pubKey;
	}
	
	public PrivateKey getPrivateKey(){
		return priKey;
	}
	
	public RSAPublicKey getRSAPubKey(){
		return (RSAPublicKey)pubKey;
	}
	
	public RSAPrivateKey getRSAPriKey(){
		return (RSAPrivateKey)priKey;
	}
	
	}