Backend Development
PHP Tutorial
PHP implements authentication example through session control_php example
PHP implements authentication example through session control_php example
The idea of session control is to be able to track users based on a session on the website. The detailed code is compiled here, friends in need can refer to it.
Overview
http protocol is stateless. For each request, the server cannot distinguish the user. PHP session control gives the user a key (an encrypted session string), which is also a proof of the user's identity. The server stores the box (database, memory database or file) that can be opened by this key. The box contains the user's various variable information.
Traditional php session usage
<?php //page1.php 启动一个会话并注册一个变量 session_start(); $_SESSION['user_var'] = "hello,codekissyoung!"; //这里的可以将$_SESSION理解为用户的箱子，实际的实现是php在服务器端生成的小文件 ?>
<?php //page2.php session_start(); echo $_SESSION['user_var'];//通过钥匙访问自己的箱子内的变量 $_SESSION['user_var'] = "bey,codekissyoung!"; ?>
<?php //page3.php 销毁钥匙,一般在用户注销时，访问page3.php文件 session_start(); session_destroy(); ?>
Ask a question, where is the key? Didn’t you see the operation of giving the user the key?
This operation is done for us by PHP behind the scenes. Since you visit page1.php and run the program, session_start();, PHP will generate a PHPSESSID based on some conditions at the moment (user IP, browser number, time, etc.) After the variable, http response is returned to the client, the PHPSESSID is already stored in your browser cookie. Every time you visit this domain name again, the PHPSESSID will be sent to the server. This PHPSESSID is the user key I am talking about here.
One more question, the security of this PHPSESSID, is it easy to be stolen, is it easy to be forged, is it easy to be tampered with?
Using HTTPS can prevent tampering. Do not use PHPSESSID, but generate a secret key for the user to prevent forgery. As for whether it is easy to be stolen, there is really no research on it. For example, if your computer is connected to the Internet and hackers invade your computer.
Save the generated secret key in the browser cookie
- Set cookies
- setCookie('key','value',time()+3600);
- Delete cookies
- setCookie('key','',time()-1);
Achieve single sign-on: session sharing
Single sign-on: Multiple subsystems share a user authentication system. If you log in at one place, you can access all subsystems.
Imagine this scenario: Assume that the php environments of servers A and B are the same. The user got his key on server A, and then he took the key to access server B. Does he know server B?
Obviously not, the key generated by server A is not recognized by the server.
Solution: Regardless of whether the user accesses A or B, I store the generated key in C (the same database, or cache system). When the user accesses A or B again, both A and B will ask C: the user's key. Is the key right? If it is correct, the user can use the box stored in A or B.
<?php
session_regenerate_id();//重置 session 字符
$session_info=array('uid'=>$uid,'session'=>session_encrypt(session_id().time()));
//下一步将，$session_info 存到 C 中
?>The following is an example of php implementing authentication through session control
Authentication application principal: authmain.PHP
<?php
//开启一个会话
session_start();
if((!isset($userid))||(!isset($password))) {
$userid=$_POST['userid'];
$password=$_POST['password'];
//连接数据库
$db_conn=new mysqli("localhost", "root", "","auth");
if(mysqli_connect_errno()){
echo '连接数据库失败：'.mysqli_connect_error();
exit();
}
//执行SQL查询语句
$query="SELECT * FROM authorized_users WHERE name='".$userid."' and password=sha1('".$password."')";
$result=$db_conn->query($query);
if($result->num_rows>0){
//注册一个会话变量
$_SESSION['valid_user']=$userid;
}
//断开数据库连接
$db_conn->close();
}
?>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>身份验证</title>
</head>
<body>
<h1>主页</h1>
<?php
//判断用户是否已经登录
if(isset($_SESSION['valid_user'])){
echo $_SESSION['valid_user'].',您好，你已经登录';
echo '<a href="logout.php">退出登录</a><br/>';
}else{
if(isset($userid)){
echo '您没有登录成功';
}else{
echo '您还没有登录<br/>';
}
?>
<form method="post" action="authmain.php">
<p>用户名：<input type="text" name="userid"></p>
<p>密码：<input type="password" name="password"></p>
<p><input type="submit" name="submit" value="登录"></p>
</form>
<?php
}
?>
<br/>
<a href="members_only.php">登录进入</a>
</body>
</html>
Valid user check for website: members_only.php
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>身份验证</title>
</head>
<body>
<?php
//启用会话
session_start();
echo '<h1>会员有效</h1>';
if(isset($_SESSION['valid_user'])){
echo "<p>".$_SESSION['valid_user'].",您好，您已经登录成功</p>";
echo '<p>会员可享受折扣优惠</p>';
}else{
echo '<p>您还没有登录成功</p>';
echo '<p>只有登录成功才能查看此页</p>';
}
echo '<a href="authmain.php">返回主页</a>';
?>
</body>
</html>
Logout session variables and destroy session: logout.php
<?php
//启用会话
session_start();
$olduser=$_SESSION['valid_user'];
//注销会话变量
unset($_SESSION['valid_user']);
//销毁会话
session_destroy();
?>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>退出登录</title>
</head>
<body>
<h1>您退出登录了！</h1>
<?php
if(!empty($olduser)){
echo '退出登录了<br/>';
}else{
echo '您没有登录过，所以当然也不存在退出登录<br/>';
}
?>
<a href="authmain.php">返回主页</a>
</body>
</html> The above is the entire content of this article. I hope it will be helpful to everyone’s study. I also hope that everyone will support Script Home.
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1664
14
1423
52
1317
25
1268
29
1242
24
Explain JSON Web Tokens (JWT) and their use case in PHP APIs.
Apr 05, 2025 am 12:04 AM
JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,
Explain late static binding in PHP (static::).
Apr 03, 2025 am 12:04 AM
Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.
PHP Program to Count Vowels in a String
Feb 07, 2025 pm 12:12 PM
A string is a sequence of characters, including letters, numbers, and symbols. This tutorial will learn how to calculate the number of vowels in a given string in PHP using different methods. The vowels in English are a, e, i, o, u, and they can be uppercase or lowercase. What is a vowel? Vowels are alphabetic characters that represent a specific pronunciation. There are five vowels in English, including uppercase and lowercase: a, e, i, o, u Example 1 Input: String = "Tutorialspoint" Output: 6 explain The vowels in the string "Tutorialspoint" are u, o, i, a, o, i. There are 6 yuan in total
What are PHP magic methods (__construct, __destruct, __call, __get, __set, etc.) and provide use cases?
Apr 03, 2025 am 12:03 AM
What are the magic methods of PHP? PHP's magic methods include: 1.\_\_construct, used to initialize objects; 2.\_\_destruct, used to clean up resources; 3.\_\_call, handle non-existent method calls; 4.\_\_get, implement dynamic attribute access; 5.\_\_set, implement dynamic attribute settings. These methods are automatically called in certain situations, improving code flexibility and efficiency.
PHP and Python: Comparing Two Popular Programming Languages
Apr 14, 2025 am 12:13 AM
PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.
PHP in Action: Real-World Examples and Applications
Apr 14, 2025 am 12:19 AM
PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.
PHP: A Key Language for Web Development
Apr 13, 2025 am 12:08 AM
PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
The Enduring Relevance of PHP: Is It Still Alive?
Apr 14, 2025 am 12:12 AM
PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.
