With all the CDNs and content been served from several locations for a single web page for example, would it be possible to implement a maintainable whitelist in something like a proxy? Does it makes sense? Or I would break half of the websites?
With all the CDNs and content been served from several locations for a single web page for example, would it be possible to implement a maintainable whitelist in something like a proxy? Does it makes sense? Or I would break half of the websites?
yes, it would be possible
Any suggestions on the how?
Noscript. Ublock origin strict/export mode, where you must manually accept connections. Dns filtering. A socks proxy. VPN. Etc, there exist many ways.
But which of these methods is best depends on what you are trying to do.
Not enough context. Depending on what you proxy, you can allowlist DNS and IPs. You can use DNS to query domains for alternative delivery sources.