subresource-integrity
Installation
SKILL.md
Add Subresource Integrity to external scripts
When you load JavaScript from a CDN, you're trusting that CDN completely — if it's compromised, attackers can serve malicious JavaScript to all your users. SRI adds a cryptographic hash to the tag; the browser refuses to execute the script if the hash doesn't match the downloaded content, protecting users even if the CDN is compromised or the URL is hijacked.
Quick Reference
- Add integrity="sha384-..." to and tags loading from CDNs
- Always pair integrity with crossorigin="anonymous"
- Generate hashes with openssl or online tools — CDN providers usually supply them
- SRI blocks execution if the file hash doesn't match, preventing CDN compromise attacks
Check
Find all external and tags in this HTML that load from CDNs and don't have integrity attributes. List each one.
Fix
Add appropriate integrity and crossorigin attributes to external CDN resources. Generate the SHA-384 hashes for each resource.