Java Des 加密与解密

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/mrlin6688/article/details/88574179

package com.sobot.util.crypto;


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 org.apache.commons.codec.binary.Base64;

/**
 * Des加密解密类
 * 
 * @author sobot
 */

public class Des {
 
    private final static String DES = "DES";
 
    public static void main(String[] args) throws Exception {
        String data = "123 456";
        String key = "wang!@#$%";
        System.err.println(encrypt(data, key));
        System.err.println(decrypt(encrypt(data, key), key));
 
    }
     
    /**
     * DES字符串加密
     * @param data 要加密的数据
     * @param key  加密密钥
     * @return 加密后base64编码密文
     * @throws Exception
     */
    public static String encrypt(String data, String key) throws Exception {
        byte[] bt = encrypt(data.getBytes(), key.getBytes());
        String strs = Base64.encodeBase64String(bt);
        return strs;
    }
 
    /**
     * DES字符串解密
     * @param data 要解密数据
     * @param key  解密密钥
     * @return 解密后明文数据
     * @throws IOException
     * @throws Exception
     */
    public static String decrypt(String data, String key) throws IOException,
            Exception {
        if (data == null)
            return null;
        byte[] buf = Base64.decodeBase64(data);
        byte[] bt = decrypt(buf,key.getBytes());
        return new String(bt);
    }
 
    /**
     * 对byte数组进行des加密
     * @param data 加密数据byte数组
     * @param key  加密密钥byte数组
     * @return 加密后byte数组
     * @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);
    }
     
     
    /**
     * 对byte数组进行解密
     * @param data 解密bute数组
     * @param key  解密密钥byte数组
     * @return 解密后byte数组
     * @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);
    }
}