Re: [Doh] Suggestion: The final endpoint should be able to temporarly act as a recursive DoH resolver

Ulrich Wisser <> Wed, 24 October 2018 09:54 UTC

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From: Ulrich Wisser <>
Date: Wed, 24 Oct 2018 11:53:57 +0200
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To: Sebastian Nielsen <>
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Subject: Re: [Doh] Suggestion: The final endpoint should be able to temporarly act as a recursive DoH resolver
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I can see the reason behind this but would like to point out a few details.

- clients would have to do dnssec validation
- servers would need to not only provide answers to queries, but also the
dnssec chain for the validation
- what should happen with not dnssec signed answers? Dropped? How will the
client get an answer in that case?

Additionally, I think it should be made clearer that an endpoint should
only answer for a known list of domains, as to not get abused by clients.
- what should a server do if a not dnssec signed domain is configured in
it's list?


Sebastian Nielsen <> schrieb am Mi., 24.
Okt. 2018 um 11:38 Uhr:

> I have a suggestion for extending the DoH specification:
> The final endpoint, should be able to act as a authorative and sometimes
> recursive DoH resolver if it has support for the DoH protocol, during the
> normal HTTPS connection.
> This could mean that once you reach a WWW server, theres no need for
> looking up domains like and such since the result of
> such domains could be returned by the original HTTPS server over the same
> connection as the website traffic goes over.
> If the HTTPS server has other domains for example
> as links it could return those aswell but only
> if they are DNSSEC signed, and for security, a DoH client should only
> accept results for a third-party domain if the result is DNSSEC signed.
> To avoid abuse, a WWW server supporting this extension should only allow
> queries for its own domain and subdomains, and also queries for any
> resources it has been configured to resolve (and this type of configuration
> could be done automatically by for example a script on the web server that
> adds all external links to its ACL)
> This would mean an WWW server serving content for itself and also have
> links to could have those 2 domains cached in
> its internal DoH resolver and resolve for those, thus once you reach a
> webpage’s server, you no longer need to talk to your recursive DoH serverl,
> which also increases privacy.
> This could lead to much faster response times aswell, as the WWW server
> would have the information about all its linked hosts permanently cached
> and updated regularly.
> Think like OCSP stapling but for DNS responses instead.
> Best regard, Sebastian Nielsen
> _______________________________________________
> Doh mailing list
Ulrich Wisser