DES加解密时 Given final block not properly padded 的解决方案

事情的经过是这个样子的。。。。。。

先说说问题是怎么出现的。根据客户需求，需要完成一个一键登录的功能，于是我的项目中就诞生了DesUtil，但是经过几百次测试，发现有一个登录直接报错！难道又遇到神坑啦！！

让我们先看看源代码，干货来了！

       package com.kwp.main.util.security;

import java.io.IOException;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;

public class DesUtil {

    private final static String DES = "DES";
    public final static String KEY = "EA22DAB57022E2560A376749E3408196A9E287D800E068E5";
    /**
     * Description 根据键值进行加密
     * @param data
     * @param key 加密键byte数组
     * @return
     * @throws Exception
     */
    public static String encrypt(String data, String key) throws Exception {
        byte[] bt = encrypt(data.getBytes(), key.getBytes());
        String strs = new BASE64Encoder().encode(bt);
        return strs;
    }

    /**
     * Description 根据键值进行解密
     * @param data
     * @param key 加密键byte数组
     * @return
     * @throws IOException
     * @throws Exception
     */
    public static String decrypt(String data, String key) throws IOException,
            Exception {
        if (data == null)
            return null;
        BASE64Decoder decoder = new BASE64Decoder();
        byte[] buf = decoder.decodeBuffer(data);
        byte[] bt = decrypt(buf,key.getBytes());
        return new String(bt);
    }

    /**
     * Description 根据键值进行加密
     * @param data
     * @param key 加密键byte数组
     * @return
     * @throws Exception
     */
    private static byte[] encrypt(byte[] data, byte[] key) throws Exception {
        // 生成一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始密钥数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密钥工厂，然后用它把DESKeySpec转换成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);

        // 用密钥初始化Cipher对象
        cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);

        return cipher.doFinal(data);
    }


    /**
     * Description 根据键值进行解密
     * @param data
     * @param key 加密键byte数组
     * @return
     * @throws Exception
     */
    private static byte[] decrypt(byte[] data, byte[] key) throws Exception {
        // 生成一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始密钥数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密钥工厂，然后用它把DESKeySpec转换成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);

        // 用密钥初始化Cipher对象
        cipher.init(Cipher.DECRYPT_MODE, securekey, sr);

        return cipher.doFinal(data);
    }

    public static void main(String[] args)throws Exception{
       //加密
       System.out.println(DesUtil.encrypt("zhaohui", DesUtil.KEY));
       System.out.println(DesUtil.encrypt("0", DesUtil.KEY));
       //解密
       System.out.println(DesUtil.decrypt("/sVcz2jGgPQ=", DesUtil.KEY));
    }
}