Depth resolution: The central role of HTTP head in Web security

HTTP Headers is Web Key channels for the exchange of metadata between browsers and servers. While users cannot see them when they view the pages, the head field determines the page's cache strategy, the type of content, cross-domain access and, most importantly, the level of security protection.

Why should developers focus on HTTP heads?

Defense against common attack: By correctly Configure Content-Security-Policy (CSP) and X-Frame-Options , can effectively defend the cross-site script (XSS) and click on the hijacking attack.
Force encrypted transmission: Strict-Transport-Security (HSTS) Tell browsers to access the site only via HTTPS to prevent attacks by intermediaries.
Performance optimization: Cache-Control and ETag The local cache time of the resources is determined, which directly affects the speed of loading the site.
Privacy protection: Referrer-Policy You can control the amount of information leaked to a third party website when you click on a link.

How to solve the specific API and Web security problems?

Scene one: API interface is illegally called. Checking response headers Access-Control-Allow-Origin 。 If set to * And there is no reasonable authentication mechanism, your API may be called in bad faith by any website. This solver will mark this broad CORS Configure to risk.

Scenario 2: Browser misreported "Mixed Content". If you have HTTPS on your website, the script quoted is HTTP, and the browser will intercept. By Parsing Upgrade-Insecure-Requests Head, you can force the browser to upgrade all unsafe requests to HTTPS.

Common security head analysis guide

Strict-Transport-Security： Best practice is set-up max-age At least half a year and includes includeSubDomains 。 This ensures the ecological security of the entire domain name.

X-Content-Type-Options： Set As nosniff The browser can be prevented from trying to “sniff” the content type, thus avoiding certain attacks based on forgery based on mimetypes.