There are some services that I expose to the internet (using Apache reverse proxy) that really should be accessed by only a small set of devices. Requiring client certificates seems like a great way to reduce the attack surface and prevent brute force attacks (since the attacker doesn’t even get a chance to attempt a login).
I wonder about the difficulty on the client side as well as other practical implications. The clients are smartphones of various makes.
I’m already running Headscale, and it works great. But to expose individual services to individual devices it feels like an overkill. I don’t actually need all these devices to connect to the tailnet all the time, and some of these devices I don’t even want to be able to access the entire tailnet.
I recommend taking a look at the new Tailscale access controls > policies (aka “grants”). Much easier to understand than their old ACLs. You can quickly draw up rules that only let specific devices access specific nodes and even only specific ports.
There’s one small potential point of confusion, in that you can’t use node names directly in the rules. You have to go to access controls > definitions > hosts and make up a name there assigned to the node IP address, and then you can use that name in a policy.
In other words, even if you already have a tailnode called “nas” with a fixed IP, you can’t just say “nas” in a policy. You have to go to hosts, define one called “nas” that points to that tailnode’s IP, and then you can use “nas” in the policy… 🤪
I understand the logic, which is that hosts and definitions in general are much more powerful and can define IP netmasks and IP groups and then you can use those groups in policies… but boy, the redundancy when you have to do this for single nodes that are already assigned a name and an IP is rubbing me wrong.