Laravel is a popular PHP framework that provides many practical tools and security measures, allowing developers to easily build advanced web applications. Among them, preventing cross-site request forgery (CSRF) attacks is a very important security measure. In this article, we will introduce how to effectively prevent CSRF attacks in Laravel.

What is a CSRF attack?

Before taking a deeper look at how Laravel prevents CSRF attacks, let’s first understand what a CSRF attack is. CSRF attack (Cross-Site Request Forgery), also known as "one-click attack" or "session riding", is a network attack technique. The attacker uses the user's session permissions on the authenticated website to perform the attack without the user's knowledge. perform illegal operations. In short, attackers trick users into performing operations on a website, thereby illegally transferring funds or stealing users' sensitive information.

The principle of a CSRF attack is not complicated. The attacker forges a form or link on a website, which contains requests to perform some dangerous operations. The attacker will then induce the user to click or submit these fake forms. When the user performs these operations, the attacker can use this opportunity to steal the user's information and perform some illegal operations.

How to prevent CSRF attacks?

Laravel provides some methods to prevent CSRF attacks. The following are some commonly used methods:

1. CSRF Token

Laravel uses CSRF token to To prevent CSRF attacks, the token is sent on form submission and is verified on the server side. Laravel provides a unique token for each form and AJAX request in each application. This token can be embedded in the form and AJAX request. When the request is sent to the server, Laravel will verify that the token matches the Randomly generated token matching in the application. If the match is successful, the request is processed.

In Laravel, you can use the csrf_field() function to generate a hidden field containing the CSRF token, which can be embedded in the form. For example:

<form action="/your/url" method="POST">
    {{ csrf_field() }}
    <!-- 其他表單字段 -->
</form>

2. X-CSRF-Token header

When using AJAX to send a POST request, you can add the X-CSRF-Token field in the request header. This field Contains the CSRF token, which Laravel will validate against.

For example:

$.ajaxSetup({
    headers: {
        'X-CSRF-Token': $('meta[name="_token"]').attr('content')
    }
});

3. CSRF validation middleware

In Laravel, through the CSRF validation middleware, you can create a new value for each POST, PUT, PATCH or DELETE request to force CSRF verification. If the request does not contain the correct CSRF token, the request will be rejected and an HTTP 419 status code will be returned.

In order to enable CSRF verification middleware, just add CSRF middleware in the middleware group.

// app/Http/Kernel.php
protected $middlewareGroups = [
    'web' => [
        // 其他中間件
        IlluminateFoundationHttpMiddlewareVerifyCsrfToken::class,
    ],

    // 其他中間件組
];

Note: The CSRF token will change with each request, so when making an Ajax request, you need to reset the X-CSRF-Token field in the request header, otherwise the verification will fail.

Summary

Laravel provides developers with powerful tools and security measures to prevent CSRF attacks. By using CSRF tokens, X-CSRF-Token headers and CSRF verification middleware, CSRF attacks can be effectively prevented and user information security protected. When using Laravel for web development, it is important to pay attention to security issues and actively seek out and apply various security measures to ensure that the website and user information are not attacked and threatened.

The above is the detailed content of How to prevent csrf in laravel. For more information, please follow other related articles on the PHP Chinese website!