Re: [Doh] New Privacy Considerations Section Proposal

[nusenu <[e-mail]>]

Patrick McManus wrote:
> On Thu, Jun 21, 2018 at 7:08 AM, nusenu <[e-mail]> wrote:
>> So because a comprehensive treatment is hard and obviously not the primary
>> goal of the
>> document a comparative statement of the privacy implications of DoH wrt
>> other DNS protocols
>> from Sara's text is no longer mentioned at all?
>>
>>
> I feel like it is absolutely mentioned!
> 
> The text makes clear that issues arise at the IP, TCP, TLS, and HTTPS
> layers.

by "comparative statement" I was referring to 
"
DNS-over-TLS, for example, would normally contain no client identifiers in the DNS messages and a resolver would see only a stream of DNS queries originating from a client IP address. Whereas if DoH clients commonly include several headers in a DNS message (e.g. user-agent and accept-language) this could lead to the resolver being able to identify the source of individual DNS requests not only to a specific end user device but to a specific application.
"

but Sara made already a better version of it in [1]:
> I propose:
> 
> OLD:
> “DoH inherits the privacy properties of the HTTPS stack and is not known to introduce new concerns beyond that of HTTPS."
> 
> NEW:
> “As a deliberate design choice DoH inherits the privacy properties of
> the HTTPS stack and is not known to introduce new concerns beyond that of HTTPS.
> As a consequence, however, it does introduce new privacy concerns when compared
> with DNS over UDP, TCP or TLS (RFC7858). The rationale for this decision is that 
> retaining the ability to leverage the full functionality of the HTTP ecosystem is more
> important than placing any constraints on this new protocol based on privacy considerations."


that hasn't gotten any feedback from the draft authors yet.

[1] https://mailarchive.ietf.org/arch/msg/doh/_ju-J52e5cf7UNpgwhCbq5pln5Y



>> I'd like to understand the reasoning for NOT including specific privacy
>> friendly
>> recommendations in the document, because currently the document mentions
>>
> 
> DoH uses and requires HTTP but does not redefine it. DoH is not a mere
> tunnel for DNS and applications should leverage what features fit their
> needs. 

Understood. Now it primarily about making this clear in the draft and the
proposed paragraph above is IMHO doing that very well.


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