Re: [Doh] [Ext] Seeking input on draft-03

Paul Hoffman <paul.hoffman@icann.org> Thu, 08 February 2018 18:18 UTC

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From: Paul Hoffman <paul.hoffman@icann.org>
To: Mike Bishop <mbishop@evequefou.be>
CC: "doh@ietf.org" <doh@ietf.org>
Thread-Topic: [Ext] [Doh] Seeking input on draft-03
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Date: Thu, 8 Feb 2018 18:18:15 +0000
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Subject: Re: [Doh] [Ext] Seeking input on draft-03
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On Feb 8, 2018, at 10:11 AM, Mike Bishop <mbishop@evequefou.be>; wrote:
> I’m inclined to think this is a positive change.  We’re trying to do something better than the current world of “trust the local DNS server because unauthenticated DHCP says so”, and promiscuous trust just because a server claims it support DOH via a .well-known endpoint isn’t really any better.  The client should know the hostname(s) of the DOH server(s) it wants to use, and it should authenticate the DOH server against that hostname.

To be clear: that's not what the current draft says. It says that the client needs to know *the full URL to the DOH service* of the DOH server it wants to use.

The effect of this is that, if a user wants to tell its browser to use DOH on example.com, they need to know the full URL and type it into some config dialog for the browser. Or, possibly worse, browsers that want to enable DOH will have to have a list of popular DOH servers and the URL associated with each server, somewhat akin to the preloaded key pinning we see now; that list would also need to allow the user to extend the list.

Using .well-known/ or some other fixed prefix would make it so that configuring DOH was less onerous for users.

--Paul Hoffman