DES 加密

java 代码

package encrypt;

import java.security.*;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;


public class DesEncrypt {

    private static final String PASSWORD_CRYPT_KEY = "xredleaf";
    private final static String DES = "DES";



/**

* 加密

* @param src 数据源

* @param key 密钥，长度必须是8的倍数

* @return  返回加密后的数据

* @throws Exception

*/

public static byte[] encrypt(byte[] src, byte[] key)throws Exception {

       //DES算法要求有一个可信任的随机数源

       SecureRandom sr = new SecureRandom();

       // 从原始密匙数据创建DESKeySpec对象

       DESKeySpec dks = new DESKeySpec(key);

       // 创建一个密匙工厂，然后用它把DESKeySpec转换成

       // 一个SecretKey对象

       SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);

       SecretKey securekey = keyFactory.generateSecret(dks);

       // Cipher对象实际完成加密操作

       Cipher cipher = Cipher.getInstance(DES);

       // 用密匙初始化Cipher对象

       cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);

       // 现在，获取数据并加密

       // 正式执行加密操作

       return cipher.doFinal(src);

    }



    /**

    * 解密

    * @param src 数据源

    * @param key 密钥，长度必须是8的倍数

    * @return   返回解密后的原始数据

    * @throws Exception

    */

    public static byte[] decrypt(byte[] src, byte[] key)throws Exception {

       // DES算法要求有一个可信任的随机数源

       SecureRandom sr = new SecureRandom();

       // 从原始密匙数据创建一个DESKeySpec对象

       DESKeySpec dks = new DESKeySpec(key);

       // 创建一个密匙工厂，然后用它把DESKeySpec对象转换成

       // 一个SecretKey对象

       SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);

       SecretKey securekey = keyFactory.generateSecret(dks);

       // Cipher对象实际完成解密操作

       Cipher cipher = Cipher.getInstance(DES);

       // 用密匙初始化Cipher对象

       cipher.init(Cipher.DECRYPT_MODE, securekey, sr);

       // 现在，获取数据并解密

       // 正式执行解密操作

       return cipher.doFinal(src);

    }

 /**

  * 密码解密

  * @param data

  * @return

  * @throws Exception

  */

 public final static String decrypt(String data){

    try {

     return new String(decrypt(hex2byte(data.getBytes()),

        PASSWORD_CRYPT_KEY.getBytes()));

   }catch(Exception e) {

   }

   return null;

 }

 /**

  * 密码加密

  * @param password

  * @return

  * @throws Exception

  */

 public final static String encrypt(String password){

   try {

     return byte2hex(encrypt(password.getBytes(),PASSWORD_CRYPT_KEY.getBytes()));
   }catch(Exception e) {

   }

   return null;

 }

/**

* 二行制转字符串

* @param b

* @return

*/

 public static String byte2hex(byte[] b) {

       String hs = "";

       String stmp = "";

       for (int n = 0; n < b.length; n++) {

           stmp = (java.lang.Integer.toHexString(b[n] & 0XFF));

           if (stmp.length() == 1)

               hs = hs + "0" + stmp;

           else

               hs = hs + stmp;

       }

       return hs.toUpperCase();

  }



 public static byte[] hex2byte(byte[] b) {

   if((b.length%2)!=0)

      throw new IllegalArgumentException("长度不是偶数");

       byte[] b2 = new byte[b.length/2];

       for (int n = 0; n < b.length; n+=2) {

         String item = new String(b,n,2);

         b2[n/2] = (byte)Integer.parseInt(item,16);

       }

   return b2;
 }
}