


Yii Framework Official Guide Series 51 - Special Topic: Security Measures (Security)
1. Prevention of cross-site scripting attacks
Cross-site scripting attacks (referred to as XSS), that is, web applications collect information from users User data. Attackers often inject JavaScript, VBScript, ActiveX, HTML or Flash into vulnerable web applications to confuse visitors and collect visitor information. For example, a poorly designed forum system may display user input without checking. An attacker can inject a piece of malicious JavaScript code into the post content. In this way, when other visitors read this post, these JavaScript codes can be run on the visitor's computer.
One of the most important measures to prevent XSS attacks is: Content inspection before displaying the content entered by the user. For example, you can escape HTML in content. But in some cases this method is not advisable, because this method disables all HTML tags.
Yii integrates HTMLPurifier and provides developers with a very useful component CHtmlPurifier, which encapsulates the HTMLPurifier class. It can remove all malicious code from the audited content through effective review, security and whitelisting functions, and ensure that the content filtered after filtering meets standards.
CHtmlPurifier component can be used as a widget or filter. When used as a widget, CHtmlPurifier can safely filter the content displayed in the view. The following is a code example:
##
<?php $this->beginWidget('CHtmlPurifier'); ?> //...这里显示用户输入的内容... <?php $this->endWidget(); ?>
src address of this image points to a bank website:
http://www.php.cn/. If the user visits this malicious webpage after logging into the bank's website, the user's browser will send an instruction to the bank's website. The content of this instruction may be "transfer 10,000 yuan to the attacker's account." Cross-site attacks take advantage of a specific website that the user trusts, while CSRF attacks, on the contrary, take advantage of the user's specific user identity on a website.
GET The request only allows retrieval of data and cannot modify any data on the server. The
POST request should contain some random values that can be recognized by the server to ensure that the source of the form data and the destination of the running results are the same.
POST. The core of this mechanism is to set a random data in the cookie, and then compare it with the corresponding value in the
POST data submitted by the form.
return array( 'components'=>array( 'request'=>array( 'enableCsrfValidation'=>true, ), ), );
- You can use SSL to create a secure channel and only send the authentication cookie over an HTTPS connection. In this way, the attacker cannot decrypt the cookie sent.
- Set the expiration time of cookies. Do the same for all cookies and seesion tokens. This reduces the chance of being attacked.
- Prevent cross-site code attacks, because it can trigger arbitrary code in the user's browser, and these codes may leak the user's cookies.
- Verify the cookie content when the cookie changes.
return array( 'components'=>array( 'request'=>array( 'enableCookieValidation'=>true, ), ), );
$_COOKIES.
// 检索一个名为$name的cookie值 $cookie=Yii::app()->request->cookies[$name]; $value=$cookie->value; ...... // 设置一个cookie $cookie=new CHttpCookie($name,$value); Yii::app()->request->cookies[$name]=$cookie;

Load balancing affects session management, but can be resolved with session replication, session stickiness, and centralized session storage. 1. Session Replication Copy session data between servers. 2. Session stickiness directs user requests to the same server. 3. Centralized session storage uses independent servers such as Redis to store session data to ensure data sharing.

Sessionlockingisatechniqueusedtoensureauser'ssessionremainsexclusivetooneuseratatime.Itiscrucialforpreventingdatacorruptionandsecuritybreachesinmulti-userapplications.Sessionlockingisimplementedusingserver-sidelockingmechanisms,suchasReentrantLockinJ

Alternatives to PHP sessions include Cookies, Token-based Authentication, Database-based Sessions, and Redis/Memcached. 1.Cookies manage sessions by storing data on the client, which is simple but low in security. 2.Token-based Authentication uses tokens to verify users, which is highly secure but requires additional logic. 3.Database-basedSessions stores data in the database, which has good scalability but may affect performance. 4. Redis/Memcached uses distributed cache to improve performance and scalability, but requires additional matching

Sessionhijacking refers to an attacker impersonating a user by obtaining the user's sessionID. Prevention methods include: 1) encrypting communication using HTTPS; 2) verifying the source of the sessionID; 3) using a secure sessionID generation algorithm; 4) regularly updating the sessionID.

The article discusses PHP, detailing its full form, main uses in web development, comparison with Python and Java, and its ease of learning for beginners.

PHP handles form data using $\_POST and $\_GET superglobals, with security ensured through validation, sanitization, and secure database interactions.

The article compares PHP and ASP.NET, focusing on their suitability for large-scale web applications, performance differences, and security features. Both are viable for large projects, but PHP is open-source and platform-independent, while ASP.NET,

PHP's case sensitivity varies: functions are insensitive, while variables and classes are sensitive. Best practices include consistent naming and using case-insensitive functions for comparisons.


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

WebStorm Mac version
Useful JavaScript development tools

mPDF
mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SublimeText3 English version
Recommended: Win version, supports code prompts!

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

Notepad++7.3.1
Easy-to-use and free code editor
