https://dns.google/dns-query – RFC 8484 (GET and POST)
https://dns.google/resolve? – JSON API (GET)
And tunneling obfuscated traffic is easy... =3
I wonder if DoH requests can be easily proxied? So if I set up https://www.mydomain.com/dns-query on a U.S.-based cloud server and proxy_pass all requests to Google or Cloudflare, and point my browser at my server, will it work?
Perhaps someone will put a configured wifi router image together over Christmas holidays for demonstration purposes... because it is fun to ignore tcp drop DoS too.
Tunneling well-obfuscated traffic is easier than most imagine... and IDS technology will fail to detect such things without an OS OSI layer snitch. =3
That's not how that works. DoH resolvers need an IP address, not a domain name. Sure, Google could host DoH on www.google.com, www.youtube.com, etc. but most users are not going to be savvy enough to find those IPs and use them.
Then again, perhaps users savvy enough to try to use DoH to bypass these blocks would also be fine with this.
Very few people configure DoH on their own. It's up to the DoH-enabled client software (mostly browsers) to obtain lists of resolver IPs and keep them up to date.
If Cloudflare, for example, really wanted to make their DoH traffic indistinguishable from other HTTPS traffic, they could literally host DoH on any domain or IP under their control and rotate the list every now and then.
Even the UK/China firewall can be tunneled over, but the ramifications for those that do so can be dire. =3
So far clients have chosen availability instead of fighting this fight.
It is quite easy for example, to bonce traffic through a reverse proxy on a Tor tunnel, and start ignoring spoofed drop-connection packets (hence these bypass local DNS, tunnel to a proxy IP to obfuscate Tor traffic detection, and exit someplace new every minute or so.) This is a common method to escape the cellular LTE/G5 network sandbox.
Ever played chase the Kl0wN? Some folks are difficult to find for various reasons.
Have a nice day, =3