【推荐】JAVA基础◆浅谈3DES加密解密

 1 package my3des;
 2  
 3 import java.io.UnsupportedEncodingException;
 4  
 5 import javax.crypto.Cipher;
 6 import javax.crypto.SecretKey;
 7 import javax.crypto.spec.SecretKeySpec;
 8  
 9  
10 /**
11  * SecretUtils {3DES加密解密的工具类 }
12  * @author William
13  * @date 2013-04-19
14  */
15 public class SecretUtils {
16  
17     //定义加密算法，有DES、DESede(即3DES)、Blowfish
18     private static final String Algorithm = "DESede";    
19     private static final String PASSWORD_CRYPT_KEY = "2012PinganVitality075522628888ForShenZhenBelter075561869839";
20     
21     
22     /**
23      * 加密方法
24      * @param src 源数据的字节数组
25      * @return 
26      */
27     public static byte[] encryptMode(byte[] src) {
28         try {
29              SecretKey deskey = new SecretKeySpec(build3DesKey(PASSWORD_CRYPT_KEY), Algorithm);    //生成密钥
30              Cipher c1 = Cipher.getInstance(Algorithm);    //实例化负责加密/解密的Cipher工具类
31              c1.init(Cipher.ENCRYPT_MODE, deskey);    //初始化为加密模式
32              return c1.doFinal(src);
33          } catch (java.security.NoSuchAlgorithmException e1) {
34              e1.printStackTrace();
35          } catch (javax.crypto.NoSuchPaddingException e2) {
36              e2.printStackTrace();
37          } catch (java.lang.Exception e3) {
38              e3.printStackTrace();
39          }
40          return null;
41      }
42     
43     
44     /**
45      * 解密函数
46      * @param src 密文的字节数组
47      * @return
48      */
49     public static byte[] decryptMode(byte[] src) {      
50         try {
51             SecretKey deskey = new SecretKeySpec(build3DesKey(PASSWORD_CRYPT_KEY), Algorithm);
52             Cipher c1 = Cipher.getInstance(Algorithm);
53             c1.init(Cipher.DECRYPT_MODE, deskey);    //初始化为解密模式
54             return c1.doFinal(src);
55         } catch (java.security.NoSuchAlgorithmException e1) {
56             e1.printStackTrace();
57         } catch (javax.crypto.NoSuchPaddingException e2) {
58             e2.printStackTrace();
59         } catch (java.lang.Exception e3) {
60             e3.printStackTrace();
61         }
62         return null;
63      }
64     
65     
66     /*
67      * 根据字符串生成密钥字节数组 
68      * @param keyStr 密钥字符串
69      * @return 
70      * @throws UnsupportedEncodingException
71      */
72     public static byte[] build3DesKey(String keyStr) throws UnsupportedEncodingException{
73         byte[] key = new byte[24];    //声明一个24位的字节数组，默认里面都是0
74         byte[] temp = keyStr.getBytes("UTF-8");    //将字符串转成字节数组
75         
76         /*
77          * 执行数组拷贝
78          * System.arraycopy(源数组，从源数组哪里开始拷贝，目标数组，拷贝多少位)
79          */
80         if(key.length > temp.length){
81             //如果temp不够24位，则拷贝temp数组整个长度的内容到key数组中
82             System.arraycopy(temp, 0, key, 0, temp.length);
83         }else{
84             //如果temp大于24位，则拷贝temp数组24个长度的内容到key数组中
85             System.arraycopy(temp, 0, key, 0, key.length);
86         }
87         return key;
88     } 
89 }

 1 package my3des;
 2  
 3 public class Main {
 4  
 5     /**
 6      * @param args
 7      */
 8     public static void main(String[] args) {
 9         String msg = "3DES加密解密案例";
10         System.out.println("【加密前】：" + msg);
11         
12         //加密
13         byte[] secretArr = SecretUtils.encryptMode(msg.getBytes());    
14         System.out.println("【加密后】：" + new String(secretArr));
15         
16         //解密
17         byte[] myMsgArr = SecretUtils.decryptMode(secretArr);  
18         System.out.println("【解密后】：" + new String(myMsgArr));
19     }
20 }