4 ms·

I mean, these are the steps that can bring it. And with Let's Encrypt as a safe fallback, it actually is feasible this time. Long shot? Yes. But not impossible

by cyberax 11mo ago

I mean, these are the steps that can bring it. And with Let's Encrypt as a safe fallback, it actually is feasible this time. Long shot? Yes. But not impossible.

tptacek 11mo ago
The first step you'd need is a reliable way to deliver DNSSEC records to browsers, which does not currently exist. So I feel like you're missing at least a step 0, if not a step -1 (of getting ~anybody to actually sign zones.)
- kbolino 11mo ago
  Aren't browsers generally implementing their own DNS resolution (via DoH) nowadays anyway? Not sure it helps that much, but operating systems not enforcing/delivering DNSSEC seems like a side-stepped problem now.
  - tptacek 11mo ago
    No, not as a general rule they aren't. And remember, the DNSSEC record delivery problem isn't an issue for the majority of all browser sessions, just a small minority that are on paths that won't pass DNSSEC records reliably. Since you can't just write those paths off, and you can't really reliably detect them, you end up needing a resolution fallback --- at which point you might as well not be using DANE. This was a big enough issue that there was a whole standards push to staple DNSSEC records to the TLS handshake (which then fell apart).
- cyberax 11mo ago
  I sign my zones :) The reliable way is DoH/DoT that are rapidly going to become the standard. They don't suffer from fragmentation issues, so they can reliably get the DNSSEC chain. Or maybe the next step is putting the stapled response into the certificate. Perhaps it can even be used by Let's Encrypt as a part of the challenge, providing the incentive to get it right. The original stapled DNSSEC experiment was suffering from misaligned incentives. CAs didn't care at all about it.
  - tptacek 11mo ago
    Huh? What did CAs have to do with stapling?
    - cyberax 11mo ago
      Stapling needs to be an intermediary step, in parallel with existing trusted CAs. When stapling was tried first in Chrome, no CAs were interested in setting up something like Let's Encrypt, using DNSSEC to automatically issue certificates.
      - tptacek 11mo ago
        No it doesn't? Why would it? I'm confused by what it is you think CAs have to do with DNSSEC stapling. CAs are absolutely not the reason DANE staples failed.
        cyberax 11mo ago
        Staples failed because they couldn't work alone. They were considered a replacement for completely self-signed certificates. That's why the committee tried to mandate the stillborn pinning idea. The option to use stapling in addition to a CA-signed certificate was not really considered. After all, if you paid for a CA-signed cert then why would you bother with stapling?
        tptacek 11mo ago
        Whatever thing you're talking about, it does not appear to be DANE stapling.
        cyberax 11mo ago
        It does? The idea was to staple the DNSSEC chain to the TLS, so that clients wouldn't have needed to do the whole DNS pointer chasing themselves. The problem is that the MITM-ing adversary can just strip the DNSSEC chain and then replace the certificate. Without having a DNSSEC-enabled resolver, the client can't detect that. So stapling doesn't provide any additional security over the self-signed certificates. The only proposed fix was to pin the DNSSEC-enabled URLs, using TOFU (Trust On First Use). And nobody wanted that. There was no real discussion about adding the stapling in _addition_ to CA-signed certificates. Because at that time there was no point in doing that, no CA wanted to provide free signing. This is changed now. The self-signed certificates are no longer status quo.
ekr____ 11mo ago
What's the incentive for individual sites or browsers to do this? From the site's perspective, they're going to need to have a WebPKI certificate for the foreseeable future, basically until there is no appreciable population of WebPKI-only clients, which is years in the future. So DANE is strictly more work. From the browser's perspective, very few sites actually support DANE, and the current situation is satisfactory, so why go to any additional effort? In order for technologies to get wide deployment, they usually need to be valuable to individual ecosystem actors at the margin, i.e., they have to get value by deploying them today. Even stipulating that an eventual DANE-only system is better, it doesn't provide any benefit in the near term, so it's very hard to get deployment.
- tptacek 11mo ago
  A fun note: I vibecoded a dumb thingy that monitors the top 1000 zones on the Tranco research list of popular zones for DNSSEC status: https://dnssecmenot.fly.dev/ https://dnssecmenot.fly.dev/ Obviously, the headline is that just 2% of the top 100 zones are signed (thanks to Cloudflare). But the funnier thing is: in 5+ months of letting this thing run, it's picked up just three changes to DNSSEC status among all the zones it monitors. The third happened just an hour or so ago, when Canva disabled DNSSEC.
- crote 11mo ago
  DANE could've worked as an alternative to LetsEncrypt, if all CAs had refused to cross-sign it and essentially killed it for years until everyone's cert stores had caught up.

by cyberax 11mo ago

I mean, these are the steps that can bring it. And with Let's Encrypt as a safe fallback, it actually is feasible this time. Long shot? Yes. But not impossible.

tptacek 11mo ago

The first step you'd need is a reliable way to deliver DNSSEC records to browsers, which does not currently exist. So I feel like you're missing at least a step 0, if not a step -1 (of getting ~anybody to actually sign zones.)

kbolino 11mo ago
Aren't browsers generally implementing their own DNS resolution (via DoH) nowadays anyway? Not sure it helps that much, but operating systems not enforcing/delivering DNSSEC seems like a side-stepped problem now.
- tptacek 11mo ago
  No, not as a general rule they aren't. And remember, the DNSSEC record delivery problem isn't an issue for the majority of all browser sessions, just a small minority that are on paths that won't pass DNSSEC records reliably. Since you can't just write those paths off, and you can't really reliably detect them, you end up needing a resolution fallback --- at which point you might as well not be using DANE. This was a big enough issue that there was a whole standards push to staple DNSSEC records to the TLS handshake (which then fell apart).
cyberax 11mo ago
I sign my zones :) The reliable way is DoH/DoT that are rapidly going to become the standard. They don't suffer from fragmentation issues, so they can reliably get the DNSSEC chain. Or maybe the next step is putting the stapled response into the certificate. Perhaps it can even be used by Let's Encrypt as a part of the challenge, providing the incentive to get it right. The original stapled DNSSEC experiment was suffering from misaligned incentives. CAs didn't care at all about it.
- tptacek 11mo ago
  Huh? What did CAs have to do with stapling?
  - cyberax 11mo ago
    Stapling needs to be an intermediary step, in parallel with existing trusted CAs. When stapling was tried first in Chrome, no CAs were interested in setting up something like Let's Encrypt, using DNSSEC to automatically issue certificates.
    - tptacek 11mo ago
      No it doesn't? Why would it? I'm confused by what it is you think CAs have to do with DNSSEC stapling. CAs are absolutely not the reason DANE staples failed.
      - cyberax 11mo ago
        Staples failed because they couldn't work alone. They were considered a replacement for completely self-signed certificates. That's why the committee tried to mandate the stillborn pinning idea. The option to use stapling in addition to a CA-signed certificate was not really considered. After all, if you paid for a CA-signed cert then why would you bother with stapling?
        tptacek 11mo ago
        Whatever thing you're talking about, it does not appear to be DANE stapling.
        cyberax 11mo ago
        It does? The idea was to staple the DNSSEC chain to the TLS, so that clients wouldn't have needed to do the whole DNS pointer chasing themselves. The problem is that the MITM-ing adversary can just strip the DNSSEC chain and then replace the certificate. Without having a DNSSEC-enabled resolver, the client can't detect that. So stapling doesn't provide any additional security over the self-signed certificates. The only proposed fix was to pin the DNSSEC-enabled URLs, using TOFU (Trust On First Use). And nobody wanted that. There was no real discussion about adding the stapling in _addition_ to CA-signed certificates. Because at that time there was no point in doing that, no CA wanted to provide free signing. This is changed now. The self-signed certificates are no longer status quo.

ekr____ 11mo ago

What's the incentive for individual sites or browsers to do this? From the site's perspective, they're going to need to have a WebPKI certificate for the foreseeable future, basically until there is no appreciable population of WebPKI-only clients, which is years in the future. So DANE is strictly more work. From the browser's perspective, very few sites actually support DANE, and the current situation is satisfactory, so why go to any additional effort? In order for technologies to get wide deployment, they usually need to be valuable to individual ecosystem actors at the margin, i.e., they have to get value by deploying them today. Even stipulating that an eventual DANE-only system is better, it doesn't provide any benefit in the near term, so it's very hard to get deployment.

tptacek 11mo ago
A fun note: I vibecoded a dumb thingy that monitors the top 1000 zones on the Tranco research list of popular zones for DNSSEC status: https://dnssecmenot.fly.dev/ https://dnssecmenot.fly.dev/ Obviously, the headline is that just 2% of the top 100 zones are signed (thanks to Cloudflare). But the funnier thing is: in 5+ months of letting this thing run, it's picked up just three changes to DNSSEC status among all the zones it monitors. The third happened just an hour or so ago, when Canva disabled DNSSEC.
crote 11mo ago
DANE could've worked as an alternative to LetsEncrypt, if all CAs had refused to cross-sign it and essentially killed it for years until everyone's cert stores had caught up.