OPSnet
Enable Tor detection of user IPs without plugging all exit nodes into IP ban list
There's two possible ways to detect if a given IP address is part of Tor or not. We could just generate a static list (and update it once in a while) based off using something like https://check.torproject.org/cgi-bin/TorBulkExitList.py. Alternatively, we could generate requests to https://www.torproject.org/projects/tordnsel.html.en (example NodeJS script at https://github.com/assafmo/IsTorExit), but this might involve quite a bit of overhead to do this.
In either case, after doing the check, we can catch the response of "is it tor?" into a $_SERVER variable (or within $LoggedUser) such that so long as the IP address remains constant, we don't have to re-ask that question.
Has this been implemented?
Inserting this static IP list into an nginx blocking rule can prevent users from using Tor.
An example: https://help.dreamhost.com/hc/en-us/articles/216456127-Blocking-IPs-with-Nginx
