3 ms·

Why do they have to use self-signed certs? Ship the device with a valid cert for $last_three_octets_of_mac_address.$vendor.com to the device, and print it clear

by geofft 7y ago

Why do they have to use self-signed certs? Ship the device with a valid cert for $last_three_octets_of_mac_address.$vendor.com to the device, and print it clearly on the setup instructions. Typing in something like d63d15.ui.com isn't onerous. The CA/Browser Forum allows certs up to 27 months - do routers sit on store shelves for 27 months before being configured? Do they even sit for 12 months? (Once they're online, they can renew their cert, possibly with the help of the vendor who can track the private key or something.)

londons_explore 7y ago
No need for even that. TLS should have an extension which says "I don't know how to verify my identity, but send this data to vendor.com and then they'll verify my identity". Vendor.com can then look at the opaque blob forwarded from their hardware and decide if they want to deligate trust to it.
- geofft 7y ago
  That doesn't quite work, because the premise of accessing a router setup page is that your internet connection doesn't work yet. So your router has to be able to prove its identity to the client entirely offline. (You cannot special-case "This server is untraceable", else a repressive government could blackhole that server and trigger the relaxed validation rules.)
jeroenhd 7y ago
That would require significant effort for the vendor to set up and most internet devices such as routers are an absolutely minimal cost device. Literally every cent counts in production and vendors rather remove some features than shell out the 2 cents extra to add another 64mb of storage. Furthermore, this would require either not being able to change the IP for your device (bad) or sending information about the layout of your network to the vendor (I wouldn't trust them with that info). Very few people care about this and the effort of maintaining a custom DNS and a CA certificate system (which, by the way, would need to be subjected to rigorous security testing) just isn't worth it. Lastly, what's the point? Adding a little padlock isn't worth it if anyone can get a certificate for the router ip anyway. How do you ensure that the router connecting to your IP really has the mac address it claims? It only takes one person to get root on their router to invalidate the entire security system and given how somehow router vendors are still shipping command injection vulnerabilities, I wouldn't assume that they can prevent that as much as they'd like. What I want is the option to give a router my own security certificate instead of the self signed one. Let me use my own CA or let me mess around with letsencrypt, split-horizon DNS and Selenium scripts if that's what I need. Consumers don't care about TLS on their router and this would be the cheapest option to solve it for prosumers.
therealjumbo 7y ago
We sell industrial equipment which will live its entire life (20+ years) off the internet. Browsers and the people who sit on these committees are understandably more focused on their own use cases, but there really does need to be a viable certificate solution for small embedded devices, preferably works with mDNS too. I'm not going to hold my breath, but until this happens any/all IOT devices will remain largely insecure. Big co's (like my employer) can develop and deploy a custom solution, most companies cannot.
- geofft 7y ago
  That's a little bit of a different problem, since the client end of the connection isn't the general public. (At least for industrial equipment.) The router problem is that you need a normal, unconfigured web browser to be able to access the router's config page. The immediate solution that occurs to me is installing a private CA, possibly one with name constraints for the vendor, because private CAs aren't held to the same rules about validity. I'm curious why this doesn't work - is it just that the tooling needed to make it happen isn't polished enough for small vendors? I'm guessing that internet of things devices are, by their name, on the internet and can talk to a CA. Yes, this will require some way to give them a real domain name, but you could either give them names on the vendor's site or encourage people to get a domain name for themselves.

by geofft 7y ago

londons_explore 7y ago

No need for even that. TLS should have an extension which says "I don't know how to verify my identity, but send this data to vendor.com and then they'll verify my identity". Vendor.com can then look at the opaque blob forwarded from their hardware and decide if they want to deligate trust to it.

geofft 7y ago
That doesn't quite work, because the premise of accessing a router setup page is that your internet connection doesn't work yet. So your router has to be able to prove its identity to the client entirely offline. (You cannot special-case "This server is untraceable", else a repressive government could blackhole that server and trigger the relaxed validation rules.)

jeroenhd 7y ago

That would require significant effort for the vendor to set up and most internet devices such as routers are an absolutely minimal cost device. Literally every cent counts in production and vendors rather remove some features than shell out the 2 cents extra to add another 64mb of storage. Furthermore, this would require either not being able to change the IP for your device (bad) or sending information about the layout of your network to the vendor (I wouldn't trust them with that info). Very few people care about this and the effort of maintaining a custom DNS and a CA certificate system (which, by the way, would need to be subjected to rigorous security testing) just isn't worth it. Lastly, what's the point? Adding a little padlock isn't worth it if anyone can get a certificate for the router ip anyway. How do you ensure that the router connecting to your IP really has the mac address it claims? It only takes one person to get root on their router to invalidate the entire security system and given how somehow router vendors are still shipping command injection vulnerabilities, I wouldn't assume that they can prevent that as much as they'd like. What I want is the option to give a router my own security certificate instead of the self signed one. Let me use my own CA or let me mess around with letsencrypt, split-horizon DNS and Selenium scripts if that's what I need. Consumers don't care about TLS on their router and this would be the cheapest option to solve it for prosumers.

therealjumbo 7y ago

We sell industrial equipment which will live its entire life (20+ years) off the internet. Browsers and the people who sit on these committees are understandably more focused on their own use cases, but there really does need to be a viable certificate solution for small embedded devices, preferably works with mDNS too. I'm not going to hold my breath, but until this happens any/all IOT devices will remain largely insecure. Big co's (like my employer) can develop and deploy a custom solution, most companies cannot.

geofft 7y ago
That's a little bit of a different problem, since the client end of the connection isn't the general public. (At least for industrial equipment.) The router problem is that you need a normal, unconfigured web browser to be able to access the router's config page. The immediate solution that occurs to me is installing a private CA, possibly one with name constraints for the vendor, because private CAs aren't held to the same rules about validity. I'm curious why this doesn't work - is it just that the tooling needed to make it happen isn't polished enough for small vendors? I'm guessing that internet of things devices are, by their name, on the internet and can talk to a CA. Yes, this will require some way to give them a real domain name, but you could either give them names on the vendor's site or encourage people to get a domain name for themselves.