[Node implements data encryption]

一、Node实现数据加密

1、加密的分类

（1）对称加密：也称为单密钥加密.The same key is used for encryption and decryption.
（2）非对称加密：有两把钥匙（公钥和私钥）
（3）摘要算法：把任意长度的输入,Generates a series of fixed-length pseudo-random numbers according to the algorithm(没有密钥,The encryption process is irreversible)

2、MD5（摘要算法）在Node的使用方法

（1）安装crypto模块

npm install crypto

（2）使用crypto.createHash(‘md5’)32字节/(‘sha256’)64bytes to create encrypted objects
（3）使用加密对象的update（明文）进行加密,然后调用digest(‘hex’)Returns a fixed-length hexadecimal string

3、示例

• The user's registered password is encrypted and stored in the database

（1）首先安装模块

npm install mysql2
npm install sequelize

（2）Next, create a configuration object for the database connectionseqconfig.js文件.

//1、导入sequelize模块,引入框架
const Sequelize = require('sequelize')

//2、配置数据库连接对象
const mysqlDemo = new Sequelize('xy','root','123456',{
    
    host:'localhost',
    port:3306,
    dialect:'mysql',//数据库方言,类型
    pool:{
    //数据库连接池
        max:10,
        min:3,
        idle:100000
    }
})
//3、Export a configuration object for a database connection
 module.exports = mysqlDemo

（3）model的admin.js的模块,使用sequelize建立模型(类),该模型实现与数据表的orm映射.

const Sequelize = require('sequelize')
const orm =require('../seqconfig')

const AdminModel =orm.define('admin',{
    
    Id:{
    
        type:Sequelize.INTEGER,
        primaryKey:true,//主键
        autoIncrement:true,//自增
        field:'id'
    },
    userName:{
    
        type:Sequelize.STRING,
        allowNull:false,
        field:'username'
    },
    userPwd:{
    
        type:Sequelize.STRING,
        field:'userpwd'
    }
},{
    
    freezeTableName:true,
    timestamps:false
})
module.exports = AdminModel;

（4）Use the model created in step 3 to proceedcrud操作

const express = require('express')
const crypto = require('crypto')
const AdminModel = require('../config/model/admin')
const router = express.Router()

//http://localhost:3000/md5/register
router.post('/register',(req, res) => {
    
    let name =req.body.username
    let pwd = req.body.userpwd
    //对密码进行加密
    //生成加密对象
  let hash = crypto.createHash('md5')
  //Encrypt with an encryption object and generate a hex string
  let newPwd = hash.update(pwd).digest('hex')
  //Save the username and encrypted password to the database
    AdminModel.create({
    
        userName:name,
        userPwd:newPwd
    }).then((result)=>{
    
        res.json({
    
            code:1001,
            msg:'保存成功'
        })
    }).catch((err)=>{
    
        console.log(err)
        res.json({
    
            code:1002,
            msg:'保存失败'
        })
    })
})

//http://localhost:3000/md5/login
router.post('/login',(req, res) => {
    
    let name = req.body.username
    let pwd =req.body.userpwd
    //对密码进行加密
    //生成加密对象
    let hash = crypto.createHash('md5')
    //Encrypt with an encryption object and generate a hex string
    let newPwd = hash.update(pwd).digest('hex')
    AdminModel.findOne({
    
        where:{
    
            userNmae:name
        }
    }).then((admin)=>{
    
        if(admin.userPwd === newPwd){
    
            res.json({
    
                code:1001,
                msg:'验证成功'
            })
        }else{
    
            res.json({
    
                code:1002,
                msg:'密码错误,验证失败'
            })
        }
    })
})

module.exports =router;

（5）Don't forget to configure at the endapp.js文件

var md5Router = require('./routes/md5')
app.use('/md5',md5Router)

验证：
Part of the code for the fourth step：The user's registered password is encrypted and stored in the database

//http://localhost:3000/md5/register
router.post('/register',(req, res) => {
    
    let name =req.body.username
    let pwd = req.body.userpwd
    //对密码进行加密
    //生成加密对象
  let hash = crypto.createHash('md5')
  //Encrypt with an encryption object and generate a hex string
  let newPwd = hash.update(pwd).digest('hex')
  //Save the username and encrypted password to the database
    AdminModel.create({
    
        userName:name,
        userPwd:newPwd
    }).then((result)=>{
    
        res.json({
    
            code:1001,
            msg:'保存成功'
        })
    }).catch((err)=>{
    
        console.log(err)
        res.json({
    
            code:1002,
            msg:'保存失败'
        })
    })
})

可以看到在postman测试成功：
我们再来看看数据库,You can see that the user's password encryption information is saved in the database：

Part of the code for the fourth step,验证用户是否可以登录：

//http://localhost:3000/md5/login
router.post('/login',(req, res) => {
    
    let name = req.body.username
    let pwd =req.body.userpwd
    //对密码进行加密
    //生成加密对象
    let hash = crypto.createHash('md5')
    //Encrypt with an encryption object and generate a hex string
    let newPwd = hash.update(pwd).digest('hex')
    AdminModel.findOne({
    
        where:{
    
            userName:name
        }
    }).then((admin)=>{
    
        if(admin.userPwd === newPwd){
    
            res.json({
    
                code:1001,
                msg:'验证成功'
            })
        }else{
    
            res.json({
    
                code:1002,
                msg:'密码错误,验证失败'
            })
        }
    })
})

可以看到在postman测试成功：

（6）前后端分离,So we are going to write a front-end page,进行前后端交互.

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style> div{
       width: 500px; margin: 100px auto; } </style>
<body>
    <div>
        <!-- <form action="" method="post"> -->
            <label>
                用户名：<input type="text" id="userName" name="username">
            </label>
            <br><br>
            <label>
                密&nbsp;&nbsp;&nbsp;码：<input type="password" id="userPwd" name="userpwd">
            </label>
            <br><br>
            &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
           <button type="button" id="btn_reset">重置</button>
           &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
           <button type="button" id="btn_submit">提交</button>
        <!-- </form> -->
        <br><br>
       <span id="msg"></span>
    </div>
    <script src="../js/jquery-3.4.1.js"></script>
    <script> $(function(){
      //jQuery入口函数 //1、给登录按钮绑定click事件 $('#btn_submit').click(function(){
       //2、获取用户输入的密码和用户名 let name=$('#userName').val() let pwd = $('#userPwd').val() //3.调用ajax函数向服务器发送异步的请求 $.post('http://localhost:3000/md5/login',{
      username:name,userpwd:pwd},function(result){
       $('#msg').html(result.msg) },'json') }) }) </script>
</body>
</html>

Enter the user Zhang Sanhe password123456后,显示验证成功,It also indicates that the login is successful：