OPNsense Forum

English Forums => Web Proxy Filtering and Caching => Topic started by: bryanjones on January 05, 2026, 08:31:26 AM

Title: Question about Squid Web Proxy
Post by: bryanjones on January 05, 2026, 08:31:26 AM
Hello,
Can the Squid web proxy be configured to filter URLs without requiring a certificate installation on client devices?

I've successfully set it up with a manually imported certificate, but I'm curious if Squid can perform URL filtering like some commercial firewalls do, without needing to install a certificate on the endpoints.

Thanks in advance!

Last edited by geometry dash 3d (https://geometrydash3d.com) two days ago
Title: Re: Question about Squid Web Proxy
Post by: Patrick M. Hausen on January 05, 2026, 09:17:49 AM
With explicit proxy configuration on the client, yes. Transparently, no.
Title: Re: Question about Squid Web Proxy
Post by: meyergru on January 05, 2026, 09:28:42 AM
@bryanjones: No firewall can do that, unless you configure the client to use a specific proxy. If they claim that they can, they are selling snake oil. The best they could do is to do DNS-based filtering, which is limited to the host part of the URL.

The very principle of traffic introspection relies on breaking up the encrypted traffic, thus presenting a fake certificate to the client which it must trust. If you cannot make all of your clients do that, you are out of luck.