content: /*
   * This file is part of the zyan/wework-msgaudit.
   *
   * (c) 读心印 <aa24615@qq.com>
   *
   * This source file is subject to the MIT license that is bundled
   * with this source code in the file LICENSE.
   */
  
  package com.php127.wework.utils;
  
  import org.apache.commons.codec.binary.Base64;
  import javax.crypto.Cipher;
  import java.security.KeyFactory;
  import java.security.KeyPair;
  import java.security.KeyPairGenerator;
  import java.security.NoSuchAlgorithmException;
  import java.security.SecureRandom;
  import java.security.interfaces.RSAPrivateKey;
  import java.security.interfaces.RSAPublicKey;
  import java.security.spec.PKCS8EncodedKeySpec;
  import java.security.spec.X509EncodedKeySpec;
  import java.util.HashMap;
  import java.util.Map;
  
  public class RSAEncrypt {
      private static Map<Integer, String> keyMap = new HashMap<Integer, String>();  //用于封装随机产生的公钥与私钥
  //    public static void main(String[] args) throws Exception {
  //        //生成公钥和私钥
  //        genKeyPair();
  //        //加密字符串
  //        String message = "df723820";
  //        System.out.println("随机生成的公钥为:" + keyMap.get(0));
  //        System.out.println("随机生成的私钥为:" + keyMap.get(1));
  //        String messageEn = encrypt(message,keyMap.get(0));
  //        System.out.println(message + "\t加密后的字符串为:" + messageEn);
  //        String messageDe = decrypt(messageEn,keyMap.get(1));
  //        System.out.println("还原后的字符串为:" + messageDe);
  //    }
  
      /**
       * 随机生成密钥对
       * @throws NoSuchAlgorithmException
       */
      public static void genKeyPair() throws NoSuchAlgorithmException {
          // KeyPairGenerator类用于生成公钥和私钥对，基于RSA算法生成对象
          KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
          // 初始化密钥对生成器，密钥大小为96-1024位
          keyPairGen.initialize(1024,new SecureRandom());
          // 生成一个密钥对，保存在keyPair中
          KeyPair keyPair = keyPairGen.generateKeyPair();
          RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();   // 得到私钥
          RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();  // 得到公钥
          String publicKeyString = new String(Base64.encodeBase64(publicKey.getEncoded()));
          // 得到私钥字符串
          String privateKeyString = new String(Base64.encodeBase64((privateKey.getEncoded())));
          // 将公钥和私钥保存到Map
          keyMap.put(0,publicKeyString);  //0表示公钥
          keyMap.put(1,privateKeyString);  //1表示私钥
      }
      /**
       * RSA公钥加密
       *
       * @param str
       *            加密字符串
       * @param publicKey
       *            公钥
       * @return 密文
       * @throws Exception
       *             加密过程中的异常信息
       */
      public static String encrypt( String str, String publicKey ) throws Exception{
          //base64编码的公钥
          byte[] decoded = Base64.decodeBase64(publicKey);
          RSAPublicKey pubKey = (RSAPublicKey) KeyFactory.getInstance("RSA").generatePublic(new X509EncodedKeySpec(decoded));
          //RSA加密
          Cipher cipher = Cipher.getInstance("RSA");
          cipher.init(Cipher.ENCRYPT_MODE, pubKey);
          String outStr = Base64.encodeBase64String(cipher.doFinal(str.getBytes("UTF-8")));
          return outStr;
      }
  
      /**
       * RSA私钥解密
       *
       * @param str
       *            加密字符串
       * @param privateKey
       *            私钥
       * @return 铭文
       * @throws Exception
       *             解密过程中的异常信息
       */
      public static String decrypt(String str, String privateKey) throws Exception{
          //去头尾
          privateKey = privateKey.replaceAll("-----BEGIN PRIVATE KEY-----","").replaceAll("-----END PRIVATE KEY-----","");
          //64位解码加密后的字符串
          byte[] inputByte = Base64.decodeBase64(str.getBytes("UTF-8"));
          //base64编码的私钥
          byte[] decoded = Base64.decodeBase64(privateKey);
          RSAPrivateKey priKey = (RSAPrivateKey) KeyFactory.getInstance("RSA").generatePrivate(new PKCS8EncodedKeySpec(decoded));
          //RSA解密
          Cipher cipher = Cipher.getInstance("RSA");
          cipher.init(Cipher.DECRYPT_MODE, priKey);
          String outStr = new String(cipher.doFinal(inputByte));
          return outStr;
      }
  
  }
  
  