Re: [Doh] Suggestion on draft-ietf-doh-dns-over-https-13: Recommend DANE-TLS to authenticate the TLS-certificate
Adam Roach <adam@nostrum.com> Thu, 16 August 2018 16:29 UTC
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To: "Rene 'Renne' Bartsch, B.Sc. Informatics" <ietf=40bartschnet.de@dmarc.ietf.org>, doh@ietf.org
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From: Adam Roach <adam@nostrum.com>
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Subject: Re: [Doh] Suggestion on draft-ietf-doh-dns-over-https-13: Recommend DANE-TLS to authenticate the TLS-certificate
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On 8/16/18 10:42, Rene 'Renne' Bartsch, B.Sc. Informatics wrote: > > > Am 16.08.2018 um 15:38 schrieb Eric Rescorla: >> >> >> On Thu, Aug 16, 2018 at 1:13 AM, Rene 'Renne' Bartsch, B.Sc. >> Informatics <ietf=40bartschnet.de@dmarc.ietf.org >> <mailto:ietf=40bartschnet.de@dmarc.ietf.org>> wrote: >> >> Hi, >> >> as TLS-certificates forged or obtained by devious means have >> become common in MITM-attacks by intelligence and criminals >> I suggest to RECOMMEND authentication of the DoH-server >> TLS-certificate via DANE-TLS (RFC 6698) in section 10 (Security >> considerations). >> >> >> I don't think we should make this change. Much of the value >> proposition of DoH is that it's straightforward to run on top of >> existing HTTPS infrastructure, and as a practical matter nearly all >> of that infrastructure depends on WebPKI certs and does not do DANE. >> For that reason, this recommendation would be more aspirational than >> practical. > > The problem I see is that e.g. firewall appliances with fake > certificates by intermediate certificates can break privacy and > manipulate the DNS records. > Without proper authentication of the DoH-server certificate DoH only > protects from script-kiddies. The document does not suggest that DoH servers are used without authentication. What DoH does -- and this is a huge part of its appeal -- is leverage the existing web security model. Because it's used on top of HTTPS in general (rather than any specific version of HTTPS), I would expect that its security model evolves in lock-step with the web security model. If that eventually includes DANE in some capacity, then DoH will naturally do the same thing. For your own uses, if you are so opposed to the web security model that you believe it will not work for your application, I encourage you to look into RFC 7858, with particular attention to section 4, as well as draft-ietf-dprive-dtls-and-tls-profiles. /a
- [Doh] Suggestion on draft-ietf-doh-dns-over-https… Rene 'Renne' Bartsch, B.Sc. Informatics
- Re: [Doh] Suggestion on draft-ietf-doh-dns-over-h… Star Brilliant
- Re: [Doh] Suggestion on draft-ietf-doh-dns-over-h… Rene 'Renne' Bartsch, B.Sc. Informatics
- Re: [Doh] Suggestion on draft-ietf-doh-dns-over-h… Star Brilliant
- Re: [Doh] Suggestion on draft-ietf-doh-dns-over-h… Rene 'Renne' Bartsch, B.Sc. Informatics
- Re: [Doh] Suggestion on draft-ietf-doh-dns-over-h… Eric Rescorla
- Re: [Doh] Suggestion on draft-ietf-doh-dns-over-h… Rene 'Renne' Bartsch, B.Sc. Informatics
- Re: [Doh] Suggestion on draft-ietf-doh-dns-over-h… Eric Rescorla
- Re: [Doh] Suggestion on draft-ietf-doh-dns-over-h… Adam Roach