Before Sequoia when using OpenDNS for VPN, could be on VPN and iMessage and other apps still work, but since Sequoia, when on VPN iMessage (text messages) etc no longer work. Once I disconnect to VPN all goes through. Is this related at all? Do have macOS firewall enabled. But not block all incoming connections.
After upgrading to Sequoia, I could not browse with Safari or Mozilla. What fixed it for me was to go to the DNS settings for my Wi-Fi connection, and add Google's DNS servers (8.8.8.8. and 8.8.4.4). They replaced the autofilled DNS servers that were there.
Were the autofilled DNS servers in RFC1918 private space (10.0.0.0/8, 192.168.0.0/16, etc.)? I had issues after the upgrade with Google Chrome being unable to access hosts in these ranges, and fixed it by going to System Settings -> Privacy & Security -> Local Network and toggling Google Chrome off and on again.
No, they weren't local. I have no idea where they came from. I couldn't even delete them, but when I added the Google servers, they autofilled ones were automatically deleted.
It worked before I upgraded to Sequoia. But I don't know enough to point fingers. Just mentioning that turning off the firewall long enough for Firefox to update fixes the problem.
There is no such thing as a remotely cross-platform DNS resolution API that has the system do the lookup and does not utterly suck for asynchronous use.
I suspect "cross-platform" is doing a lot of heavy lifting for your claim. Browser engines and application frameworks built on top of them have no trouble using platform-specific APIs under the hood.
I remember 20+ years ago when one of the most commonly seen attacks was malware configuring a proxy server in Internet Explorer which by design overrode the operating system's configuration.
What a lot of software does today by ignoring the operating system in lieu of their own shit is just like the above. If your program doesn't (or can't) respect the operating system, your shit is malware and you should reconsider who you write code for.
If you consider the source of income of what's most likely a considerable portion of the HN community, I think this makes more sense. Apple is one of the only companies interested in preventing tracking, and it hurts, in the billions sort of way [1][2].
At some point in my copious spare time, I plan on writing software to allowlist in my firewall outbound connections only to IPs resolved using my DNS servers.
You could also configure your router to intercept rogue plaintext DNS lookups on your network with responses from a resolver you trust (for example a Pihole, Cloudflare or Google Public DNS, Quad9, PCH, etc). Adding something like Pihole would give you comprehensive blocking and custom internal DNS entries too.
How would that work? Do you only access a really small/known set of IPs? Or would you program the firewall to only allow connections to an arbitrary IP if it had seen a DNS query to your preferred servers go out and return that IP within a few seconds prior?
In the latter case, would you have to aggressively disable local DNS caching on devices to make the behavior work (is that even possible on some devices)? How would encrypted DNS fit into this scheme?
I am fine with the only Java application I have used in the lease decade not working. I did not even bother putting a JVM on any of the OS I installed in the last 5 years. So yeah, I’d rather have fewer security holes.
I have one browser setup to do DNS differently than another. I don't want to have to set it at a system level and then need multiple systems just to run 2 browsers with different DNS lookup
Yep, I wish they would go the full way and block socket access entirely so your own outgoing traffic is always introspectable even with cert pinning. It would make it blatantly obvious when apps try shady shit.
I had a great Windows firewall like this about 20 years ago. It would pop up a dialog for every network request from an app. You could block or allow based on port or destination, or "block all". It was amazing, because as you say, it made it very obvious when an app was trying shady shit.
I would love to have that back, but I was never able to find a firewall so hostile to the user experience of the general population.
It sounds similar in spirit to Little Snitch, mentioned in the article (on macOS, but which inspired OpenSnitch, which runs on Linux). It is awesome indeed, if a bit overwhelming at first. Most regular users would just uninstall it to avoid the constant barrage of requests initially, and then every time a new piece of software tries to connect to anything.
Shady shit? Not every network request is a call to an HTTP REST API.
Blocking socket APIs would break every app that supports other protocols. Goodbye file transfer apps, VPN apps, file sync apps, database tools, SSH clients, remote desktop clients, audio and video conferencing apps, etc.