Comment by rixthefox
3 years ago
I disagree. Forging DNSSEC requires LE to strong arm the domain registrar to modify the DS keys per domain which would also require them pointing to an adversary DNS server to answer those requests with a valid signature. That action would definitely be noticed. Without DNSSEC you are back to square 1 of unsigned DNS that can be modified in-flight, a much worse situation. I personally believe we should be advocating for more DNSSEC, not less.
What I think you're advocating for is that DNSSEC should have it's own transparency log that shows when domains update or cycle their DNSSEC KSK/ZSKs which is a great idea, we would just need to get all the domain registrars on board as well which as we can already see with the transparency project, you can't get buy in from everyone.
Well, with transparency project we _did_ get buy in from everyone because browsers (like Mozilla and Google) forced it. And there are severe penalties for not obeying transparency log, and well as technical measures to enforce it (for example certs with no CT log would not work in Chrome).
This of course only works because there is competition. If TrustCor fails to behave, then this CA is dropped. Customers complain, but not very strongly - there are plenty of CAs around, it's annoying to have to switch to another one but still eminently doable. And TrustCor is out of business completely, all their investment is permanently gone.
With DNSSEC.. what do you do if you domain registrar does not play by the rules, say is caught double-issuing DS keys?
Answer is: likely nothing. Most orgs are not going to move .com to .io because of that -- there links, SEO, even things like business cards. People would complain, _maybe_ registrar would get a fine for 0.0001% of their annual income (but I would not count on this). And that's it, the system will stay insecure and they will continue to double-issue certificates.
The separation of CA from registrar is a _feature_, and a very helpful one. Competition is good, and we should not make our existing natural monopolies even more useful.
> LE to strong arm the domain registrar to modify the DS keys per domain
It is important to note that when a law enforcement with this capability would just legally take ownership of the domain instead. If the domain is under control getting domain validated certificates is trivial. There are many legal precedents with domain takedowns.
It is equally important to note that only TLDs under LE jurisdiction is ever an issue. It is not clear whether this specific attack under .ru had been ever remotely possible with any type of authenticated domains.