PHP security protection: strengthen HTTP security header configuration

With the continuous development and maturity of the Internet, security issues have also received increasing attention. As a commonly used web back-end development language, the security issues faced by PHP cannot be ignored. Here, we will introduce how to improve the security of PHP by strengthening HTTP security header configuration.

What are HTTP security headers?

HTTP security header was invented to prevent HTTP protocol attacks. Simply put, HTTP security headers are a collection of additional information included in the HTTP response. These headers tell the browser what steps it should take to protect itself. HTTP security headers usually contain the following content:

1. Content-Security-Policy: used to limit the scripts, plug-ins, etc. that can be executed in the browser to prevent cross-site scripting attacks and other types of attacks .
2. Strict-Transport-Security: Used to convey a message to the browser that this website can only be accessed through HTTPS, which can prevent man-in-the-middle attacks, etc.
3. X-Content-Type-Options: Used to prevent XSS attacks from bypassing the MIME type set by the browser in the response through the MIME type vulnerability, causing the browser to mistakenly believe that the web page content and the MIME type do not match, resulting in Cross-site scripting attacks.
4. X-Frame-Options: Used to prevent click-jacking attacks. Websites that set X-Frame-Options prohibit other sites from embedding this site's pages through iframes to achieve click-jacking attack effects.
5. X-XSS-Protection: If this response header is enabled, the browser will turn on its own XSS filter to prevent cross-site scripting attacks.

Methods to strengthen HTTP security header configuration

1. Configuring Content-Security-Policy

When configuring Content-Security-Policy, Factors such as each web application's architecture, deployment method, and dependencies need to be considered. At the same time, we need to ensure that the value of the CSP response header does not undermine the availability of the application.

If you are using a newer web application framework (such as Laravel or Symfony), then these frameworks may provide predefined CSP settings. Otherwise, it can be configured via the following code example:

header('Content-Security-Policy: default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; img-src 'self' data:');

2. Configuring Strict-Transport-Security

Strict-Transport-Security only allows connections to the website via HTTPS, so Can effectively prevent man-in-the-middle attacks or session hijacking. Strict-Transport-Security can be configured with the following code example:

header('Strict-Transport-Security: max-age=31536000; includeSubDomains; preload');

This configuration will force the browser to mark the website as Strict-Transport-Security and always use HTTPS to connect to it for the next 366 days. Website (including subdomains).

3. Configuring X-Content-Type-Options

Through the following code, you can configure X-Content-Type-Options:

header('X-Content-Type-Options: nosniff');

This configuration will Tells the browser that when the MIME type declared in the response's Content-Type header does not match the requested MIME type, the browser's interpretation of the response should be rejected.

4. Configure X-Frame-Options

Through the following code, you can configure X-Frame-Options:

header('X-Frame-Options: SAMEORIGIN');

SAMEORIGIN means that the website is only allowed in Use iframe within the same origin site. Depending on the requirements, it may also be possible to use DENY to deny all iframe embeddings.

5. Configuring Responses are checked for suspicious code and automatically blocked if suspicious code is detected.

The above is the detailed content of PHP security protection: strengthen HTTP security header configuration. For more information, please follow other related articles on the PHP Chinese website!