3 ms·

CA model is broken (>500 of CAs, race to the bottom in terms of price, security is not a part of their business model). DANE is no better. What we really want i

by exo762 12y ago

CA model is broken (>500 of CAs, race to the bottom in terms of price, security is not a part of their business model). DANE is no better. What we really want is to be able to withdraw trust. There is no point for me to trust some Iranian CA. Why should I want to trust one? Today - I have to trust it, because you can't just remove CA without breaking a percentage of websites for you. And you can't normally erase CA from existence, because on single CA rely many customers and each of them will have broken website. Please read about Convergence by Moxie Marlinspike. It solves the removing of trust problem.

Nullabillity 12y ago
With DANE it's immediately visible who you have to trust, and that can't easily be changed. If it's a .se domain then you know that only the Swedish govt can MITM that, with the current CA model any CA is able to authorize a MITM.
- tptacek 12y ago
  That would be great if looking at .COM wasn't an immediate guarantee that the USG could MITM something.
  - xorcist 12y ago
    Don't use .com if you distrust them. It's still orders of magnitude better than the CA model. The web site owner gets to choose which top domain to use and trust. It is not the end user that is supposed to value how much trust they put in each CA. That alone is the most important point right there.
    - tptacek 12y ago
      This makes absolutely no sense to me. DNSSEC is a forklift upgrade of a key piece of the architecture of the Internet. We should incur that cost so that all of the most popular sites on the Internet will end up with the USG as their CA? And that's "orders of magnitude" better than what we have now?
      - toast0 12y ago
        Today, for a .com, there are a large number of CAs (let's call it 100?) that can sign a cert. Additionally the registrar or the registry (VeriSign) can change NS and DS records due to a US court order (or otherwise) and the new destination could get a domain control validated certificate. If DANE were adopted and the current CA system abolished, then the registrar or the registry could still change the NS and DS records to takeover a domain, but that takes us from 100+ parties capable of signing a cert to 2 parties that are already part of the system.
      - xorcist 12y ago
        It is. The trifecta of three letter agencies can expropirate and generate valid certificates for .com domains today. But they can't do this for most of the other TLDs. No cryptography in the world can protect you from a fully legal domain trasfer. So, who better to be your CA than the registrar who have this power anyway?
      - xorcist 12y ago
        Also, not a "forklift upgrade". The work is done. DNSSEC is live. Your resolver probably already supports it. Your TLD probably already publishes the records.
tptacek 12y ago
You can look at TACK as a baby-step towards Convergence.
xorcist 12y ago
DANE is about 500x better than the current CA model, using your estimation. All CAs are allowed to issue certificates for almost every (not entirely true, but pretty much so) domain, while only one top domain is involved in DANE trust. I don't need to trust the Iranian top domain (which is what you mean, not "government") for all of the web that is not in .ir. I don't know about you, but 100% of my web use falls in that bucket. And if you want to visit an .ir domain you need to trust the Iranian domain registry, independently if you use CAs, DANE or even Convergence. If they change the legitimate owner of the domain (which is what you mean here!), they can just as easily get a legitimate SSL certificate in every trust model in practical use. (Indeed, if a legitimate owner of a domain couldn't get a legitimate certificate, there'd be no possibility to do things like rotate your keys and change your certificate. That would be an even bigger problem than broken CAs.) So DANE makes sense. And while there are known issues with DNSSEC, trusting governments is not one of them. Not more so than with any other model.

by exo762 12y ago

Nullabillity 12y ago

With DANE it's immediately visible who you have to trust, and that can't easily be changed. If it's a .se domain then you know that only the Swedish govt can MITM that, with the current CA model any CA is able to authorize a MITM.

tptacek 12y ago
That would be great if looking at .COM wasn't an immediate guarantee that the USG could MITM something.
- xorcist 12y ago
  Don't use .com if you distrust them. It's still orders of magnitude better than the CA model. The web site owner gets to choose which top domain to use and trust. It is not the end user that is supposed to value how much trust they put in each CA. That alone is the most important point right there.
  - tptacek 12y ago
    This makes absolutely no sense to me. DNSSEC is a forklift upgrade of a key piece of the architecture of the Internet. We should incur that cost so that all of the most popular sites on the Internet will end up with the USG as their CA? And that's "orders of magnitude" better than what we have now?
    - toast0 12y ago
      Today, for a .com, there are a large number of CAs (let's call it 100?) that can sign a cert. Additionally the registrar or the registry (VeriSign) can change NS and DS records due to a US court order (or otherwise) and the new destination could get a domain control validated certificate. If DANE were adopted and the current CA system abolished, then the registrar or the registry could still change the NS and DS records to takeover a domain, but that takes us from 100+ parties capable of signing a cert to 2 parties that are already part of the system.
    - xorcist 12y ago
      It is. The trifecta of three letter agencies can expropirate and generate valid certificates for .com domains today. But they can't do this for most of the other TLDs. No cryptography in the world can protect you from a fully legal domain trasfer. So, who better to be your CA than the registrar who have this power anyway?
    - xorcist 12y ago
      Also, not a "forklift upgrade". The work is done. DNSSEC is live. Your resolver probably already supports it. Your TLD probably already publishes the records.

tptacek 12y ago

You can look at TACK as a baby-step towards Convergence.

xorcist 12y ago

DANE is about 500x better than the current CA model, using your estimation. All CAs are allowed to issue certificates for almost every (not entirely true, but pretty much so) domain, while only one top domain is involved in DANE trust. I don't need to trust the Iranian top domain (which is what you mean, not "government") for all of the web that is not in .ir. I don't know about you, but 100% of my web use falls in that bucket. And if you want to visit an .ir domain you need to trust the Iranian domain registry, independently if you use CAs, DANE or even Convergence. If they change the legitimate owner of the domain (which is what you mean here!), they can just as easily get a legitimate SSL certificate in every trust model in practical use. (Indeed, if a legitimate owner of a domain couldn't get a legitimate certificate, there'd be no possibility to do things like rotate your keys and change your certificate. That would be an even bigger problem than broken CAs.) So DANE makes sense. And while there are known issues with DNSSEC, trusting governments is not one of them. Not more so than with any other model.