第十五章 加密算法实例1--注册登录（消息摘要算法）

15.1、原理步骤

• 注册：注册时，将用户密码加密放入数据库
• 登录：登录时，将用户密码采用上述相同的算法加密，之后再与数据库中的信息进行比对，若相同，则登录

15.2、实现（这里采用了SHA256算法，其他摘要算法MD5/SHA1/MAC类似）

注意：这里的程序是在我之前写的一个maven+spring+springmvc+mybatis+velocity整合的文章上进行的修改，具体的框架搭建以及数据库表结构等就不再啰嗦了，自己参考下边这篇博客：

http://www.cnblogs.com/java-zhao/p/5096811.html

这里只列出Java类。整个代码结构如下：

UserController

 1 package com.xxx.web;
 2
 3 import org.springframework.beans.factory.annotation.Autowired;
 4 import org.springframework.stereotype.Controller;
 5 import org.springframework.web.bind.annotation.RequestMapping;
 6 import org.springframework.web.bind.annotation.RequestParam;
 7 import org.springframework.web.bind.annotation.ResponseBody;
 8 import org.springframework.web.servlet.ModelAndView;
 9
10 import com.xxx.model.User;
11 import com.xxx.service.UserService;
12
13 @Controller
14 @RequestMapping("user")
15 public class UserController {
16
17     @Autowired
18     private UserService userService;
19
20     @ResponseBody
21     @RequestMapping("register")
22     public boolean register(@RequestParam("username") String username,
23                             @RequestParam("password") String password){
24
25         return userService.register(username, password);
26     }
27
28     @RequestMapping("login")
29     public ModelAndView login(@RequestParam("username") String username,
30                               @RequestParam("password") String password){
31         User user = userService.login(username, password);
32
33         ModelAndView modelAndView = new ModelAndView();
34         if(user == null){
35             modelAndView.addObject("message", "用户不存在或者密码错误！请重新输入");
36             modelAndView.setViewName("error");
37         }else{
38             modelAndView.addObject("user", user);
39             modelAndView.setViewName("userinfo");
40         }
41
42         return modelAndView;
43     }
44 }

UserService（这里是加解密的主战场）

 1 package com.xxx.service;
 2
 3 import java.io.UnsupportedEncodingException;
 4 import java.security.NoSuchAlgorithmException;
 5
 6 import org.springframework.beans.factory.annotation.Autowired;
 7 import org.springframework.stereotype.Service;
 8
 9 import com.util.encoder.ShaEncoder;
10 import com.xxx.dao.UserDAO;
11 import com.xxx.model.User;
12
13 @Service
14 public class UserService {
15
16     @Autowired
17     private UserDAO userDao;
18
19     public boolean register(String username, String password){
20         User user = new User();
21         user.setUsername(username);
22         try {
23             user.setPassword(ShaEncoder.encodeSHAHex(password));//对密码进行sha256加密
24         } catch (NoSuchAlgorithmException e) {
25             e.printStackTrace();
26         } catch (UnsupportedEncodingException e) {
27             e.printStackTrace();
28         }
29         return userDao.register(user);
30     }
31
32     public User login(String username, String password) {
33         User user = null;
34         try {
35             user = userDao.login(username, ShaEncoder.encodeSHAHex(password));//对密码进行sha256加密
36         } catch (NoSuchAlgorithmException e) {
37             e.printStackTrace();
38         } catch (UnsupportedEncodingException e) {
39             e.printStackTrace();
40         }
41         return user;
42     }
43 }

UserDAO

 1 package com.xxx.dao;
 2
 3 import org.springframework.beans.factory.annotation.Autowired;
 4 import org.springframework.stereotype.Repository;
 5
 6 import com.xxx.mapper.UserMapper;
 7 import com.xxx.model.User;
 8
 9 @Repository
10 public class UserDAO {
11
12     @Autowired
13     private UserMapper userMapper;
14
15     public boolean register(User user){
16         return userMapper.insertUser(user)==1?true:false;
17     }
18
19     public User login(String username ,String password){
20         return userMapper.selectByUsernameAndPwd(username, password);
21     }
22 }

UserMapper

 1 package com.xxx.mapper;
 2
 3 import org.apache.ibatis.annotations.Insert;
 4 import org.apache.ibatis.annotations.Param;
 5 import org.apache.ibatis.annotations.Result;
 6 import org.apache.ibatis.annotations.Results;
 7 import org.apache.ibatis.annotations.Select;
 8
 9 import com.xxx.model.User;
10
11 public interface UserMapper {
12
13     @Insert("INSERT INTO userinfo(username, password) VALUES(#{username},#{password})")
14     public int insertUser(User user);
15
16     @Select("SELECT * FROM userinfo WHERE username = #{username} AND password = #{password}")
17     @Results(value = { @Result(id = true, column = "id", property = "id"),
18                        @Result(column = "username", property = "username"),
19                        @Result(column = "password", property = "password")})
20     public User selectByUsernameAndPwd(@Param("username")String username ,@Param("password")String password);
21 }

ShaEncoder（这里基于Commons Codec，即CC实现的Sha256工具类）

 1 package com.util.encoder;
 2
 3 import java.io.UnsupportedEncodingException;
 4 import java.security.NoSuchAlgorithmException;
 5 import org.apache.commons.codec.digest.DigestUtils;
 6
 7 public class ShaEncoder {
 8     private static final String ENCODING = "UTF-8";
 9
10     public static String encodeSHAHex(String data) throws NoSuchAlgorithmException,UnsupportedEncodingException {
11         return new String(DigestUtils.sha256Hex(data.getBytes(ENCODING)));
12     }
13 }

代码简单易懂，自己去看逻辑，然后进行测试即可。