Re:Netgear Signed TLS Cert Private Key Disclosure
by lima on Monday January 20, 2020 @09:14AM
(#22098892)
An attacker can just dump the unique key, impersonate the device and use that for a MitM attack. There's just no way to do this securely without completely locking down the devices using hardware key management (which would be unreasonably expensive for a cheap router, plus bad for people who want to flash their own firmware).
Same level of security, and a lot of extra complexity and cost.
Re:Netgear Signed TLS Cert Private Key Disclosure
by oarsinsync on Tuesday January 21, 2020 @01:05AM
(#22104640)
Yep, and that compromises that one device in the field. Not every device globally, today and tomorrow.
Re:Netgear Signed TLS Cert Private Key Disclosure
by lima on Tuesday January 21, 2020 @03:22AM
(#22105191)
Only if each device has a unique subdomain.
Re:Netgear Signed TLS Cert Private Key Disclosure
by zonidjan on Monday January 20, 2020 @08:42AM
(#22098697)
> Fallback to HTTP reachable via port 80 on the private IP for the server.
How, exactly, is that better than using a common cert? What threat do you propose that applies to HTTPS with a shared cert, and not to HTTP?
Things to do instead of shipping TLS certs and static private keys to consumer-grade routers you sell by the thousand:
Generate a unique keypair per device.
Use this keypair to communicate upstream, in a similar fashion to CloudFlare's Keyless SSL.
This keypair you generate on the device would need to be preloaded at the factory, unique per device, and the public key would need to be stored in a database.
When a TLS handshake comes in, you verify the entire request is signed by that keypair before signing it.
Delegated online signing for a TLS handshake isn't even in the top 10 engineering challenges for cryptography in the 2020s.
Oh, and, if you don't have connectivity to upstream and your need users to connect to configure something?
Fallback to HTTP reachable via port 80 on the private IP for the server.
[0] https://gist.github.com/nstarke/a611a19aab433555e91c656fe1f0...
[1] https://twitter.com/CiPHPerCoder/status/1219228544548720640