4 ms·
> And, for bonus points, had they done so, they likely would have been able to lock out MIT of regaining control of the domain for longer than it actually took.
by agwa 8y ago
> And, for bonus points, had they done so, they likely would have been able to lock out MIT of regaining control of the domain for longer than it actually took.
How would DNSSEC have made it take longer?
- geofft 8y agoMaybe I'm confused about this detail of DNSSEC in which case I retract that claim - I thought it's possible to advertise a false key with a long TTL and use that to prevent people from accepting records from the true key, if they still have the false key cached. If it doesn't work that way (e.g. if all resolvers will update to new keys and accept signatures from them), great.
- agwa 8y agoAn attacker could certainly do that, but they could also advertise bogus records (e.g. the MX record in mit.edu's case) with long TTLs so I don't think DNSSEC makes the worst-case recovery time any longer.
- tptacek 8y agoThe ostensible difference is that they can advertise records that cryptographically lock out corrections, right? (I think this particular critique is mooted by the maximum TTLs mainstream caches will work on). This was Colm Maccarthaigh's scenario on Twitter last week.
- agwa 8y agoI did see Colm's Tweet last week. I'm just not sure what the attacker gains from the lockout being cryptographic, as opposed to being based on old-fashioned DNS caching. If the attacker gets an A record pointing to a bogus IP address cached in a bunch of places, that's just as bad as getting a bogus DNSSEC key cached - either way, users are locked out until the malicious records expire at their resolvers. DNSSEC makes many things worse, but I don't think this is one.
- tptacek 8y agoYeah, I feel like Paul Wouters also shot this scenario down pretty conclusively, but I'm sort of doing my best to reconstruct what colmmac was talking about and might not be doing the best job of it.
- geofft 8y agoAha, I think I saw that tweet too and that's where this idea got into my head. I don't know much about the low-level details of DNSSEC so please just ignore that part :)