4 ms·
How is that not equivalent to TLS? The fact that you can talk about invididual domains and their key length should be evidence enough that Qualys, or anyone els
by xorcist 9y ago
How is that not equivalent to TLS? The fact that you can talk about invididual domains and their key length should be evidence enough that Qualys, or anyone else, could do the same.
You can get a ed25519 certificate for your web server today too, but hardly anyone would be able to communicate securely with you. Until deployment reaches critical mass you are in need of a fallback. Sunsetting protocols are even harder, so there's complete equivalency there. The use of TLS is just orders of magnitude more deployed than DNSSEC.
There's also no need to suggest I am an advocate of something when stating basic facts about it. Real world systems are dependent on DNSSEC today, and nothing you or I believe will change that. I will not discuss specifics, but I am sure you recognize its use within well known public protocols such as SMTP and SSH.
- tptacek 9y agoBecause if I get a Qualys A+ configuration for my nginx, my CA can't make me vulnerable to BEAST. That's not true with the DNS.
- xorcist 9y agoHow is BEAST relevant to any of this? It might be to some theoretical encrypted DNS, but not to the signature my CA provides to my certificate ownership just as it is not to the signature my registrar provides to my domain ownership.
- tptacek 9y agoAgain: individual site owners can reliably enable modern curve crypto in TLS. Nobody can do that with DNSSEC; all DNSSEC crypto is lowest-common-denominator, where the lcd is 1024 bit or even 512(!) bit RSA.
- xorcist 9y agoI will refrain from begging you to answer the question. It is sufficient to note that every PKI is as secure as its weakest link. If my CA is 512 bit RSA, that is the security I am going to get. That public DNSSEC infrastructure is neglected in places is not really controversial or what we're discussing here, but the use of a singular trust root in place of hundreds should not be taken as evidence of incompetence from the protocol designer.
- tptacek 9y agoPlease point to the 512 bit RSA CA that Chrome, Firefox, or Safari trusts.
- xorcist 9y agoThose are public web browsers and not really relevant to the matter here. They do not, as far as I know, implement DANE and if they did they would likely not trust 512-bit RSA certificates either. (Who knows? That might even have been a good way to bootstrap a good policy baseline, had they supported it.)
- tptacek 9y agoI seriously don't understand what you're trying to say at this point.
- ietf-dane 9y agoThe 512-bit RSA keys are a distraction. You're allowed to not care about the security of your own domain, but if your DNS hosting provider does not, and you do, get a better DNS hosting provider, all but two (of any size) use stronger keys. ECDSA P-256 and P-384 are widely deployed. New algorithms will take some time to be widely supported by peer resolvers, just as TLS 1.3 will take time to be widely supported by web sites (browsers are more agile, but many websites still don't do forward-secrecy with TLS 1.2). Algorithm agility is a thorny problem.
- tptacek 9y agoI agree that 512-bit keys are a distraction; the actual problem is the number of 1024-bit keys scattered throughout the DNSSEC PKI. Algorithm agility is hard, but it's much harder in DNSSEC than it is in TLS.