Java实现的RSA加密解密算法示例_Java教程

本文实例讲述了Java实现的RSA 加密解密算法。分享给大家供大家参考，具体如下：

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									import java.awt.AlphaComposite;

									import java.awt.Color;

									import java.awt.Font;

									import java.awt.Graphics2D;

									import java.awt.Image;

									import java.awt.RenderingHints;

									import java.awt.image.BufferedImage;

									import java.io.File;

									import java.io.FileInputStream;

									import java.io.FileOutputStream;

									import java.io.ObjectInputStream;

									import java.io.ObjectOutputStream;

									import java.security.Key;

									import java.security.KeyPair;

									import java.security.KeyPairGenerator;

									import java.security.SecureRandom;

									import java.security.interfaces.RSAPrivateKey;

									import java.security.interfaces.RSAPublicKey;

									import javax.crypto.Cipher;

									public class RSAUtils{

									 public static String makekeyfile(String pubkeyfile, String prikeyfile) {

									  String result = "生成公私钥文件失败";

									  try{

									    // KeyPairGenerator用于生成公私钥对，基于RSA算法生成对象

									    KeyPairGenerator gen = KeyPairGenerator.getInstance("RSA");

									    // 初始化密钥对生成器，密钥大小为1024位

									    gen.initialize(1024);

									//    //生成强随机数

									//    SecureRandom random = new SecureRandom();

									//    gen.initialize(1024,random);

									    // 生成一个密钥对，保存在pair中

									    KeyPair pair = gen.generateKeyPair();

									    // 得到私钥

									    RSAPrivateKey priKey = (RSAPrivateKey) pair.getPrivate();

									    // 得到公钥

									    RSAPublicKey pubKey = (RSAPublicKey) pair.getPublic();

									    // 生成私钥文件

									    ObjectOutputStream os = new ObjectOutputStream(new FileOutputStream(prikeyfile));

									    os.writeObject(priKey);

									    os.flush();

									    os.close();

									    //生成公钥文件

									    os = new ObjectOutputStream(new FileOutputStream(pubkeyfile));

									    os.writeObject(pubKey);

									    os.flush();

									    os.close();

									    result = "生成公钥文件【"+pubkeyfile+"】生成私钥文件【"+prikeyfile+"】";

									  }catch(Exception e){

									  e.printStackTrace();

									  }

									  return result;

									  }

									  public static void main(String[] args) {

									  try{

									    String pubfile = "F:/images/pub.key";

									    String prifile = "F:/images/pri.key";

									    String result = null;

									    //result = makekeyfile(pubfile, prifile);

									    result = markPuPra(pubfile, prifile);

									    System.out.println(result);

									  }catch(Exception e){

									  e.printStackTrace();

									  }

									  }

									  public static String markPuPra(String pubfile,String prifile){

									  String results = "加解密出错";

									  try{

									    ObjectInputStream os = new ObjectInputStream(new FileInputStream(pubfile));

									    RSAPublicKey pubkey = (RSAPublicKey) os.readObject();

									    os.close();

									    os = new ObjectInputStream(new FileInputStream(prifile));

									    RSAPrivateKey prikey = (RSAPrivateKey) os.readObject();

									    os.close();

									    String utf = "UTF-8";

									    String msg = "##中国%%的）人@+_";

									    // 使用公钥加密私钥解密

									    System.out.println("原文: " + msg);

									    byte[] puk = handleData(pubkey, msg.getBytes(utf), 1);

									    System.out.println("加密后文件数据: " + new String(puk, utf));

									    byte[] dpuk = handleData(prikey, puk, 0);

									    System.out.println("解密后文件数据: " + new String(dpuk, utf));

									    msg = "jd#我0们的￥人+=#新";

									    // 使用私钥加密公钥解密

									    System.out.println("原文: " + msg);

									    byte[] prk = handleData(prikey, msg.getBytes(utf), 1);

									    System.out.println("加密后文件数据: " + new String(prk, utf));

									    byte[] dprk = handleData(pubkey, prk, 0);

									    System.out.println("解密后文件数据: " + new String(dprk, utf));

									    results = "加解密完成";

									  }catch(Exception e){

									  e.printStackTrace();

									  }

									  return results;

									  }

									  /**

									   *

									   * @param k

									   * @param data

									   * @param encrypt 1 加密 0解密

									   * @return

									   * @throws Exception

									   */

									  public static byte[] handleData(Key key, byte[] data, int type) throws Exception {

									    if (key != null) {

									      Cipher ci = Cipher.getInstance("RSA");

									      if (type == 1) {

									        ci.init(Cipher.ENCRYPT_MODE, key);

									        byte[] res = ci.doFinal(data);

									        return res;

									      }

									      if (type == 0) {

									        ci.init(Cipher.DECRYPT_MODE, key);

									        byte[] res = ci.doFinal(data);

									        return res;

									      }

									    }

									    return null;

									  }

									}