How to implement HTML content cleaning and filtering on the GoLang backend of AnQiCMS?

Implementing HTML content cleaning and filtering at the GoLang backend level in AnQiCMS is a crucial link to ensure website content safety, maintain healthy website operation, and enhance user experience.It is particularly important to clean and filter the content submitted by users before storing and displaying it, as it may contain malicious scripts (XSS), irregular HTML tags, and even sensitive information.

Understand the importance of HTML content cleaning and filtering

Website content management is not just about publishing information, but also about the quality and security of the content. When users can post content on the website (such as comments, forum posts, custom articles, etc.), if these contents are stored and displayed directly without restriction, it may lead to a series of problems:

1. security vulnerability (XSS attack)The malicious user may inject JavaScript code to steal other users' data (such as Cookies) or tamper with page content, which seriously harms the website and users' security.
2. Page layout is chaoticIncorrect or erroneous HTML tags may destroy the original CSS style of the page, causing layout chaos and affecting the professional image and user experience of the website.
3. Content compliance issue: Posting content that contains sensitive words, politically incorrect, or violates laws and regulations may pose operational risks to the website.
4. SEO negative impact: Links to spam, low-quality content, or pages deemed unsafe by search engines can severely damage a website's search engine ranking.

Therefore, AnQiCMS, as an enterprise-level content management system developed based on GoLang, provides an efficient and flexible HTML content cleaning and filtering mechanism to meet these challenges.

AnQiCMS backend security mechanism overview

AnQiCMS from the very beginning of the project design has considered security and efficiency as the core considerations.Its high-concurrency features based on the Go language allow for quick and real-time security checks while handling large amounts of content.The document clearly mentions that AnQiCMS includes security mechanisms such as 'anti-collection interference codes, content security management, sensitive word filtering, and other functions to ensure content safety and compliance.'This "Content Security Management" is the scope of HTML content cleaning and filtering.

On the GoLang backend, content cleaning and filtering usually occurs after user data submission, before data storage, and before reading content from the database for rendering.This intervention at critical points in the data lifecycle can ensure the purity and safety of the content from the source.

Implementation of core cleaning and filtering strategies

AnQiCMS implements HTML content cleaning and filtering on the GoLang backend, mainly focusing on the following aspects:

1. Sensitive word filtering

AnQiCMS has built-in sensitive word filtering functionality, which is the foundation of content compliance.On the GoLang backend, this feature is usually implemented by maintaining a sensitive word library.When the user submits HTML content, the system will parse the text content and match it with the vocabulary in the library.

• Implementation mechanism: An efficient matching engine based on Trie (prefix tree) or AC automata can be adopted to ensure quick response under large vocabularies and high concurrency requests. Sensitive words found can be replaced (for example, replaced with ***Or a predefined alternative word), or directly block the content and prompt the user.
• Application scenario: Articles, comments, messages, and even custom content model text fields published by users will be filtered through this layer.

2. White-list mechanism for HTML tags and attributes

To prevent XSS attacks and the destruction of the page by irregular HTML, adopting the whitelist (Whitelist) mechanism is a recognized practice in the industry.AnQiCMS strictly controls which HTML tags and attributes are allowed to appear on the backend.

• Implementation mechanismIn GoLang, you can use a dedicated HTML sanitization library (such asgithub.com/microcosm-cc/bluemondayor in the Go standard librarygolang.org/x/net/htmlThe extended application). These libraries can parse HTML text and remove all tags, attributes, and their contents that are not allowed according to the preset whitelist rules. For example,<script>tags,onerrorThe carriers of properties and malicious code will be completely deleted.
• Flexibility: For fields that need to support rich text editors (such as the editor provided by AnQiCMS), the system will allow more diverse tags and attributes (such as<img>,<a>,<strong>,<em>,<div>,<span>and the correspondingsrc,href,class,styleProperties that are secure, but still ensure that the values of these tags and properties are safe, such as checkinghrefwhether the property containsjavascript:malicious links in the protocol.

3. External link processing andrel="nofollow"

Inserting external links in content is a common requirement, but excessive and unrestricted external links may affect SEO or lead to malicious websites.AnQiCMS provides the function 'Whether to automatically filter external links' in the content settings.

• Implementation mechanismWhen this feature is enabled, the AnQiCMS GoLang backend will parse the content submitted by the user.<a>Label. The system will automatically addrel="nofollow"Property.
• function:nofollowThe attribute indicates that the search engine should not follow the link and should not pass the "weight" to the target page.This helps prevent the negative impact of spam links on website SEO and reduces the risk that the website may take on by pointing to bad content.

4. Deep defense against malicious script injection (XSS)

In addition to whitelist filtering, AnQiCMS will also strengthen XSS defense at multiple levels.

• Encoding output: Although the whitelist mechanism is already very powerful, in some cases, for special characters that may be contained in user content, the system will perform HTML entity encoding when rendering to the front-end (such as converting<Encoded as<Ensure that even if there are any fish that slip through the net, they will only be displayed as text on the browser side and not as executable code.The GoLang template engine (such as the AnQiCMS template engine similar to Django template engine) usually performs this kind of default security escaping.
• Content security managementThis may involve virus scanning and content analysis of uploaded files (especially HTML files or text files containing HTML content) to ensure that the file itself does not contain malicious payloads.

Practice: Application in AnQiCMS Content Model

AnQiCMS's flexible content model is one of its core strengths.This means that users can customize various fields, including rich text fields.Whether it is an article, product details, or a custom model introduction, the AnQiCMS backend filtering mechanism will automatically take effect for any field that may contain HTML content.

• User Content Posting: When the user creates or edits content in the backend editor, the HTML filter will be executed before the content is saved to the database.This ensures that the data stored in the database is clean and safe.
• Content Collection and Import：AnQiCMS supports content collection and batch import.For the content from external sources, backend filtering is particularly important, as it can effectively clean up potential malicious code and irregular HTML from unknown sources, protecting the website from external pollution.
• Full site content replacementAlthough it is mainly used for batch updates of keywords or links, this feature can also be used to make large-scale format adjustments or remove specific irregular HTML when the content needs it, and it can achieve deeper cleaning in conjunction with the backend logic.

Summary

In AnQiCMS, the cleaning and filtering of HTML content is not a single feature, but a series of security strategies and technical implementations integrated into the entire GoLang backend architecture.From sensitive word filtering to ensure compliance, to the white list mechanism effectively resist XSS, to the intelligent processing of external links to optimize SEO, AnQiCMS provides a comprehensive and powerful solution.This not only enhances the security of the website, reduces operation risks, but also ensures the quality of user content and the overall healthy operation of the website.As a website operator, understanding and trusting the backend mechanisms of AnQiCMS allows you to focus more on the content itself, without having to worry too much about the underlying technical security issues.

Frequently Asked Questions (FAQ)

1. The user has used in the article content<iframe>Tags, will AnQiCMS automatically filter them? What should I do if I need to embed Bilibili videos?AnQiCMS' HTML cleaning usually adopts a whitelist mechanism. By default, for security reasons,<iframe>These tags that may load external content are likely to be filtered out. If you need to allow embedding Bilibili or other videos, there are usually two ways: one is that AnQiCMS backend may provide specific configuration options, allowing administrators to add to the whitelist<iframe>Tags and their specificsrc(Source address) Domain (for example, only iframe from bilibili.com is allowed).<iframe>.

2. Does AnQiCMS support regular expression for sensitive word filtering? Can I implement batch replacement of specific HTML structures?The sensitive word filtering function of AnQiCMS mainly focuses on text matching, which usually relies on built-in or customized dictionaries for precise or fuzzy matching.The document mentions that the "Batch Replace Article Content" feature supports regular expressions.<div>Replace<span>or delete specific attributes), it can be replaced in bulk through configuration