> On Mar 8, 2016, at 11:31 AM, Brian E Carpenter <[email protected]> 
> wrote:
> 
> Hi Duane,
> 
> OK on the first two points, thanks. On the Security Considerations,
> I was a bit unclear: I was looking for a statement that running DNSSEC
> through a TLS connection will work OK, and that using DNS/TLS does not
> remove the need for DNSSEC validation.


How about this then?

   As noted earlier, DNSSEC and DNS-over-TLS are independent and fully
   compatible protocols, each solving different problems.  The use of
   one does not diminish the need nor the usefulness of the other.

DW



> Thanks
>   Brian
> 
> On 09/03/2016 08:06, Wessels, Duane wrote:
>> Hi Brian,
>> 
>> 
>>> On Mar 7, 2016, at 5:48 PM, Brian E Carpenter <[email protected]> 
>>> wrote:
>>> 
>>> I am the assigned Gen-ART reviewer for this draft. The General Area
>>> Review Team (Gen-ART) reviews all IETF documents being processed
>>> by the IESG for the IETF Chair.  Please treat these comments just
>>> like any other last call comments.
>>> 
>>> For more information, please see the FAQ at
>>> <http://wiki.tools.ietf.org/area/gen/trac/wiki/GenArtfaq>.
>>> 
>>> Document: draft-ietf-dprive-dns-over-tls-07.txt
>>> Reviewer: Brian Carpenter
>>> Review Date: 2016-03-08
>>> IETF LC End Date: 2016-03-15
>>> IESG Telechat date: 2016-03-17
>>> 
>>> Summary: Almost ready
>>> --------
>>> 
>>> Minor Issues:
>>> -------------
>>> 
>>> "3.1.  Session Initiation
>>> 
>>>  A DNS server that supports DNS-over-TLS MUST listen for and accept
>>>  TCP connections on port 853.  By mutual agreement with its clients,
>>>  the server MAY, instead, use a port other than 853 for DNS-over-TLS.
>>> 
>>>  DNS clients desiring privacy from DNS-over-TLS from a particular
>>>  server MUST establish a TCP connection to port 853 on the server.  By
>>>  mutual agreement with its server, the client MAY, instead, use a port
>>>  other than port 853 for DNS-over-TLS."
>>> 
>>> Well, that makes my head hurt. I think the only way to relieve the pain
>>> is if both of those MUSTs are replaced by "MUST by default". However,
>>> that means that both clients and servers need a configuration option
>>> to use a different port, and I think that needs to be stated too.
>> 
>> "Must by default" sounds fine with me.  I've made that change and added a
>> sentence about configuration options.  New text:
>> 
>>   A DNS server that supports DNS-over-TLS MUST by default listen for
>>   and accept TCP connections on port 853.  By mutual agreement with its
>>   clients, the server MAY, instead, use a port other than 853 for DNS-
>>   over-TLS.  In order to use a port other than 853, both clients and
>>   servers would need a configuration option in their software.
>> 
>>   DNS clients desiring privacy from DNS-over-TLS from a particular
>>   server MUST by default establish a TCP connection to port 853 on the
>> 
>> 
>> 
>>> "4.1.  Opportunistic Privacy Profile
>>>  ...
>>>  With opportunistic privacy, a client might learn of a TLS-enabled
>>>  recursive DNS resolver from an untrusted source (such as DHCP while
>>>  roaming), it might or might not validate the resolver."
>>> 
>>> This seems rather underspecified to me. How would a TLS-enabled
>>> resolver be identified in DHCP? How would it be described in
>>> an IPv6 RA (RFC6106)?
>> 
>> Such DHCP features would need to be defined.  
>> 
>> 
>>> I would have thought that the natural thing would have been to
>>> simply try TLS on port 853, and be happy if it worked.
>> 
>> How does this strike you then?
>> 
>>   With opportunistic privacy, a client might simply try port 853 on a
>>   normally configured recursive DNS resolver, or it might learn of a
>>   TLS-enabled recursive DNS resolver from an untrusted source (such as
>>   with a yet-to-be-defined DHCP extension or ICMPv6 type).  The client
>>   might or might not validate the resolver.  These choices maximize
>>   availability and performance, but they leave the client vulnerable to
>>   on-path attacks that remove privacy.
>> 
>> 
>>> 
>>> "9.  Security Considerations"
>>> 
>>> I hoped to find a comment on interaction between DNS/TLS and DNSSEC,
>>> even if the comment is only that there is no issue.
>> 
>> We mention this in the introduction, but I think its fine to repeat
>> it in Security Considerations:
>> 
>>   Note, DNS Security Extensions (DNSSEC) [RFC4033] provide _response
>>   integrity_ by defining mechanisms to cryptographically sign zones,
>>   allowing end-users (or their first-hop resolver) to verify replies
>>   are correct.  By intention, DNSSEC does not protect request and
>>   response privacy.
>> 
>> 
>> 
>> DW
>> 
>> 

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