Block blacklisted, allow everything else. Allow blacklist if authenticated
Is this possible? I'd like to block
unless a username and password is entered. Everything else will be allowed.
Currently running a transparent proxy with everything allowed, no authentication.
is this possible?
No, you cannot have authentication active in squid while also having transparent mode active.
There may be some other way to reach the same goal, however, it wouldn't involve strictly using pfSense (e.g. second proxy box you could manually configure with auth, or maybe 802.1x auth to drop into another VLAN, etc)