WordPress Data Security: Purification, Escape and Verification
When building WordPress plugins and themes for thousands of websites, be sure to handle data entering and leaving WordPress carefully. This tutorial will explore native functions for protecting, cleaning, and checking WordPress data, which is crucial in creating settings pages, HTML forms, manipulating shortcodes, and more.
What is data purification?
In short, data purification is to clean up user input. It removes text, characters, or code that are not allowed in the input.
Example: Gmail removes tags and contents from HTML messages before displaying them to prevent CSS from overwriting Gmail styles. WordPress widget titles do not allow HTML tags, and if any, will be automatically removed before saving the title.
WordPress provides multiple functions to purify different types of data:
-
sanitize_email()
: Removes characters that are not allowed in the email address. For example:sanitize_email("narayan prusty@sitepoint.com")
Output"narayanprusty@sitepoint.com"
. -
sanitize_file_name()
: Removes characters from the file name that may cause problems with the command line reference file. WordPress Media Uploader uses this function to purify media file names. For example:sanitize_file_name("_profile pic--1_.png")
Output"profile-pic-1_.png"
. -
sanitize_key()
: Options, metadata, and transient keys can only contain lowercase alphanumeric characters, dashes, and underscores. This function is used to purify the keys. For example:sanitize_key("http://SitePoint.com")
Output"httpsitepointcom"
. -
sanitize_text_field()
: Removes invalid UTF-8 characters, converts HTML-specific characters to entities, removes all tags, and removes line breaks, tabs, and extra spaces. WordPress uses this function to purify widget titles. For example:sanitize_text_field("<b>Bold</b>")
Output"Bold"
. -
sanitize_title()
: Removes PHP and HTML tags, as well as accents from strings. Convert space characters to dash. This function is used to generate slugs of articles/pages based on the article/page title, rather than purifying the title (purifying the title requiressanitize_text_field
). For example:sanitize_title("Sanítizing, Escaping and Validating Data in WordPress")
Output"sanitizing-escaping-and-validating-data-in-wordpress"
.
What is data escape?
In short, data escape is to protect the output. This is done to prevent XSS attacks and ensure that the data is displayed as expected.
Data escape converts special HTML characters into HTML entities for display rather than execution.
Example: Facebook escapes chat messages when they display to ensure that users do not run code on each other's computers.
WordPress provides some functions to escape different types of data:
-
esc_html()
: Escape HTML specific characters. -
esc_textarea()
: When displaying text in the text area, useesc_textarea()
instead ofesc_html()
becauseesc_textarea()
can double-encode entities. -
esc_attr()
: Encode,
,&
,"
, and'
characters. It never double-encodes entities. This function is used to escape the value of HTML tag attributes. -
esc_url()
: The URL may also contain JavaScript code. Therefore, if you want to display a URL or a full<a></a>
tag, thehref
attribute should be escaped, otherwise it may result in an XSS attack. -
esc_url_raw()
: Use this function if you want to store the URL in a database or for URL redirection. The difference betweenesc_url
andesc_url_raw
is thatesc_url_raw
does not replace the versus and single quotes. -
antispambot()
: This function converts email address characters into HTML entities to block spam bots.
What is data verification?
In short, data verification is about checking user input. This is to check whether the user has entered a valid value.
If the data is invalid, it will not be processed or stored. The system will ask the user to re-enter the value.
Example: When you create an account on a website, you will be asked to enter your password twice. The system will verify that the two passwords are the same.
HTML5 verification should not be relied on, as it is easily bypassed. Server-side verification is required before specific data is processed or stored.
WordPress provides some functions to verify certain types of data. Developers usually define their own functions for data validation.
-
is_email()
: Check whether the given string is an email address. -
is_serialized()
: Check whether the passed data is a string.
Conclusion
We understand the concepts of data purification, verification and escaping and their importance. Be sure to include these functions when developing WordPress themes or plugins. Many plugins are not well developed and have no escaped output, which makes the website vulnerable to potential XSS attacks.
FAQ (FAQ)
This section contains frequently asked questions about data purification, escaping, and validation in WordPress, covering its importance, how to work, best practices, and how to use WordPress functions to implement these security measures.
The above is the detailed content of Sanitizing, Escaping and Validating Data in WordPress. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

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)

The main reasons why WordPress causes the surge in server CPU usage include plug-in problems, inefficient database query, poor quality of theme code, or surge in traffic. 1. First, confirm whether it is a high load caused by WordPress through top, htop or control panel tools; 2. Enter troubleshooting mode to gradually enable plug-ins to troubleshoot performance bottlenecks, use QueryMonitor to analyze the plug-in execution and delete or replace inefficient plug-ins; 3. Install cache plug-ins, clean up redundant data, analyze slow query logs to optimize the database; 4. Check whether the topic has problems such as overloading content, complex queries, or lack of caching mechanisms. It is recommended to use standard topic tests to compare and optimize the code logic. Follow the above steps to check and solve the location and solve the problem one by one.

Miniving JavaScript files can improve WordPress website loading speed by removing blanks, comments, and useless code. 1. Use cache plug-ins that support merge compression, such as W3TotalCache, enable and select compression mode in the "Minify" option; 2. Use a dedicated compression plug-in such as FastVelocityMinify to provide more granular control; 3. Manually compress JS files and upload them through FTP, suitable for users familiar with development tools. Note that some themes or plug-in scripts may conflict with the compression function, and you need to thoroughly test the website functions after activation.

The most effective way to prevent comment spam is to automatically identify and intercept it through programmatic means. 1. Use verification code mechanisms (such as Googler CAPTCHA or hCaptcha) to effectively distinguish between humans and robots, especially suitable for public websites; 2. Set hidden fields (Honeypot technology), and use robots to automatically fill in features to identify spam comments without affecting user experience; 3. Check the blacklist of comment content keywords, filter spam information through sensitive word matching, and pay attention to avoid misjudgment; 4. Judge the frequency and source IP of comments, limit the number of submissions per unit time and establish a blacklist; 5. Use third-party anti-spam services (such as Akismet, Cloudflare) to improve identification accuracy. Can be based on the website

When developing Gutenberg blocks, the correct method of enqueue assets includes: 1. Use register_block_type to specify the paths of editor_script, editor_style and style; 2. Register resources through wp_register_script and wp_register_style in functions.php or plug-in, and set the correct dependencies and versions; 3. Configure the build tool to output the appropriate module format and ensure that the path is consistent; 4. Control the loading logic of the front-end style through add_theme_support or enqueue_block_assets to ensure that the loading logic of the front-end style is ensured.

To add custom user fields, you need to select the extension method according to the platform and pay attention to data verification and permission control. Common practices include: 1. Use additional tables or key-value pairs of the database to store information; 2. Add input boxes to the front end and integrate with the back end; 3. Constrain format checks and access permissions for sensitive data; 4. Update interfaces and templates to support new field display and editing, while taking into account mobile adaptation and user experience.

The key to adding custom rewrite rules in WordPress is to use the add_rewrite_rule function and make sure the rules take effect correctly. 1. Use add_rewrite_rule to register the rule, the format is add_rewrite_rule($regex,$redirect,$after), where $regex is a regular expression matching URL, $redirect specifies the actual query, and $after controls the rule location; 2. Custom query variables need to be added through add_filter; 3. After modification, the fixed link settings must be refreshed; 4. It is recommended to place the rule in 'top' to avoid conflicts; 5. You can use the plug-in to view the current rule for convenience

robots.txt is crucial to the SEO of WordPress websites, and can guide search engines to crawl behavior, avoid duplicate content and improve efficiency. 1. Block system paths such as /wp-admin/ and /wp-includes/, but avoid accidentally blocking the /uploads/ directory; 2. Add Sitemap paths such as Sitemap: https://yourdomain.com/sitemap.xml to help search engines quickly discover site maps; 3. Limit /page/ and URLs with parameters to reduce crawler waste, but be careful not to block important archive pages; 4. Avoid common mistakes such as accidentally blocking the entire site, cache plug-in affecting updates, and ignoring the matching of mobile terminals and subdomains.

1. Use performance analysis plug-in to quickly locate problems. For example, QueryMonitor can view the number of database queries and PHP errors, BlackboxProfiler generates function execution reports, and NewRelic provides server-level analysis; 2. Analyzing PHP execution performance requires checking time-consuming functions, debugging tools usage and memory allocation, such as Xdebug generates flame graphs to assist in optimization; 3. Monitor database query efficiency can be checked through slow query logs and index checks, QueryMonitor can list all SQL and sort by time; 4. Combining external tools such as GooglePageSpeedInsights, GTmetrix and WebPageTest to evaluate front-end plus
