logoalt Hacker News

yjftsjthsd-h • today at 6:35 AM • 3 replies • view on HN

I was under the impression that dnssec's entire value was rather controversial? I'm not a crypographer so I had to skim https://sockpuppet.org/blog/2015/01/15/against-dnssec/ and I still don't understand it, but if

> In fact, it does nothing for any of the “last mile” of DNS lookups: the link between software and DNS servers. It’s a server-to-server protocol.

is true, then I'm ... pretty unsold on its usefulness. Anyone wanna ELI5 whether that's untrue or anything's changed in the last decade?


Replies

jeroenhd • today at 9:33 AM

DNSSEC as designed is pretty useless. It was designed in an era where computers could not be relied upon to do cryptographic validation of something like DNS records, so that duty was delegated to DNS servers like the ones ISPs ran, where records could be cached.

There are also potential downsides (like someone being able to enumerate your subdomains, if you care about such a thing) and it's often switched off by default on operating systems consumers use.

However, it's the only thing that validates DNS records at this moment. That alone makes it worth enabling, in my opinion. For many domain owners, you only need to tick the checkbox in your registrar's domain control pane. If you use a modern DNS server, it's also one config flag and maybe copy/pasting a handful of fields away.

I'll gladly turn off DNSSEC the moment we come up with something better. DoT/DoH doesn't solve the same problem and no real solutions seem to have been proposed. That said, modernisation efforts are still being done. Smaller keys and modern cryptography rather than the massive RSA ones for instance.

usr1106 • today at 6:58 AM

I can't speak about the strength or weaknesses of the whole concept.

Out of curiosity I enabled DNSSEC checking beginning this year. I mostly noted nothing in my browsing. However, with 2 services I noted obscure problems that worked only partially. Some Jira plugins and Swedish railway SJ. I needed to excempt some of their domains from being checked to use their services. Of course you waste a couple of hours every time it happens because you don't think of DNSEC first when some web-based services behaves weirdly. There might be more requests not served to my browser, but I just never noticed or bothered to debug.

So not fit for general use. And even as an experienced developer it's not easy to understand why an exception would be needed. A bug in systemd? Incorrect data in DNS? A real attack?

Edit: I don't use standard DNS on port 53 at all. Blocked outgoing requests on that port. Everything DoH or DoT. Of course I need to trust those endpoints at least in repect to confidentiality. And most domains are unsigned. At least for those unsigned ones I need to just trust also in respect to integrity.

➕ show 1 reply
eqvinox • today at 10:33 AM

Note the linked post is from 2015. But also:

> domain-validated certificates remain insecure

...99% of the internet runs on DV certificates; that's what ACME & Let's Encrypt are at the end of the day.

(You might also note I didn't actually speak in favor of DNSsec, I'm just arguing that running unbound locally without having DNSsec validation enabled isn't particularly useful. I am, generally, in favor of rolling out DNSsec, but it certainly has its problems. It doesn't help against ISP tampering on unsecured domains, for example. DoT and DoH are better against that, if [and only if] you have a trustworthy cache to point them at.)