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DNS over HTTPS

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21–30 of 195 posts

Re: DNS over HTTPS

#21

Where does the privacy advantage come from? Once you resolve a hostname privately, don't you still need to use its IP address publicly for your traffic to be routed there?

One case where it might help is shared hosting: you don't know which of the domains hosted on that IP you're accessing. Narrows it down to just a few though, so IMHO not a big improvement.

Re: DNS over HTTPS

#22
post #18
post #13

Earlier quoted context omitted.

cURL supports it. See https://ec.haxx.se/usingcurl-persist.html If your question is how to reuse the connection pool for, say, 1000 DNS queries from one machine, curl already uses a connection pool. Next, to use fewer TCP connections and get faster response, my first proposal is HTTP/2 which supports TCP multiplexing such that multiple requests can be issued over a single TCP connection. Every response is return asyn…

> Every response is return asynchronously, we can achieve nonblocking. same goes for UDP which DNS runs over normally. Like the original commenter, I fail to see how stacking DNS over HTTP over TLS over TCP over IP is going to be faster than running DNS over UDP over IP. Also, you still need to resolve the address of your DNS-over-HTTP server, which you'd probably still do over traditional DNS-over-UDP. This feels li…

Zero gain except going from easy eavesdropping, blocking, censoring, etc. to effectively unblockable, private and secure? Ok.

Also you would probably need to put in the IP of the DNS server manually, exactly like you have to with DNS now.

Re: DNS over HTTPS

#23

Where does the privacy advantage come from? Once you resolve a hostname privately, don't you still need to use its IP address publicly for your traffic to be routed there?

Yes, but reverse DNS is not totally trivial (think AWS). Also current DNS can easily be MitM'd allowing attackers to insert JavaScript into web pages etc.

Re: DNS over HTTPS

#24
post #18
post #13

Earlier quoted context omitted.

cURL supports it. See https://ec.haxx.se/usingcurl-persist.html If your question is how to reuse the connection pool for, say, 1000 DNS queries from one machine, curl already uses a connection pool. Next, to use fewer TCP connections and get faster response, my first proposal is HTTP/2 which supports TCP multiplexing such that multiple requests can be issued over a single TCP connection. Every response is return asyn…

> Every response is return asynchronously, we can achieve nonblocking. same goes for UDP which DNS runs over normally. Like the original commenter, I fail to see how stacking DNS over HTTP over TLS over TCP over IP is going to be faster than running DNS over UDP over IP. Also, you still need to resolve the address of your DNS-over-HTTP server, which you'd probably still do over traditional DNS-over-UDP. This feels li…

I would love to know how widely used UDP over TLS is in the wild.

Re: DNS over HTTPS

#25
post #20

So what use does this have? DNSSEC already gives us validation of the records, and thanks to SNI, this doesn't give us any privacy. It is more complex, more centralized, and ends up slower than using actual DNS, and doesn't seem to provide any benefits. Am I missing something?

Easier to prevent censoring. DNSSEC doesn't hide the fact that you're making a DNS call, correct? With HTTPS, censors/MITMs can only see the domain you go to. The censor/MITM won't know whether I went to google.com to search or perform DNS query. Plenty of countries have blocked DNS providers they don't like, now that's harder w/out also blocking the site as a whole.

Re: DNS over HTTPS

#26

> for privacy, performance and security. I understand the privacy and security aspects. But I am wondering - how can DNS over HTTPS be more performant in the case of curl commands? A browser could probably persist the connection to the resolver and issue several requests together, but with a single curl command surely there's the overhead of initiating the first DNS resolve, the HTTPS connection, the second DNS resol…

> Side note - I just learned that performant is not a recognized word ( https://english.stackexchange.com/questions/38945/what-is-wr... ) I don't personally use the word since there are many alternatives, but its use is now definitely widespread and consistently understood. There's really no argument against the fact that it has entered the English lexicon.

Can anyone give examples of cases where “performant” would be better than “efficient”?

To my mind, the difference is that “performant” delivers results quickly, whereas “efficient” uses little energy. A performant solution might be efficient, but not necessarily, and vice versa. Does anyone else share this understanding or am I living in a linguistic bubble?

Not sure about Swedish (Daniel is Swedish), but in Finnish, we have the word “suorituskykyinen”, meaning “efficient” or “able to perform”. I can see how Finnish writers might want to use “performant” to replace this commonly used word. Perhaps there's a similar history for Swedish speakers? I sure have seen “performant” a lot in academic texts written by Finnish and Swedish speakers in the last 20 years.

Re: DNS over HTTPS

#27
I can see how DNS over HTTPS addresses security, but I do not see how it helps with privacy. After resolving the IP address over secure connection HTTPS still sends the host name unencrypted, so one can just eavesdrop on that. And if encrypted DNS becomes widespread, I suspect that various state-imposed firewalls like one Russia will just look for HTTPS connection header to block a particular site.

Re: DNS over HTTPS

#28
post #21

Where does the privacy advantage come from? Once you resolve a hostname privately, don't you still need to use its IP address publicly for your traffic to be routed there?

One case where it might help is shared hosting: you don't know which of the domains hosted on that IP you're accessing. Narrows it down to just a few though, so IMHO not a big improvement.

> One case where it might help is shared hosting: you don't know which of the domains hosted on that IP you're accessing.

That depends on your level of access/monitoring: if it's just a firewall log that shows source/destination IP, then yes - but as soon as you have any kind of packet monitoring, then the domain can be easily sniffed from the SNI header.

Re: DNS over HTTPS

#29

Earlier quoted context omitted.

> Side note - I just learned that performant is not a recognized word ( https://english.stackexchange.com/questions/38945/what-is-wr... ) I don't personally use the word since there are many alternatives, but its use is now definitely widespread and consistently understood. There's really no argument against the fact that it has entered the English lexicon.

Can anyone give examples of cases where “performant” would be better than “efficient”? To my mind, the difference is that “performant” delivers results quickly, whereas “efficient” uses little energy. A performant solution might be efficient, but not necessarily, and vice versa. Does anyone else share this understanding or am I living in a linguistic bubble? Not sure about Swedish (Daniel is Swedish), but in Finnish,…

"My mining algorithm, which uses a lot more CPU and memory, is more performant." The key being that performant is often associated w/ speed (i.e. higher performing) whereas efficient ambiguously can refer to many things you have improved on.

Re: DNS over HTTPS

#30
Anyone has good pointers on DNS over DTLS (draft RFC 8094) vs DNS over TLS (RFC 7858) vs DNS over HTTPS (this draft) ? And if you could throw in DNSSEC in the mix, that would be helpful.
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