Subject: Re: Kathleen Moriarty's Discuss on draft-ietf-httpbis-tunnel-protocol-04: (with DISCUSS and COMMENT)

From: Martin Thomson <[email-masked]>
Date: Tue, 9 Jun 2015 15:26:00 -0700

Hi Kathleen,

I've responded separately to the secdir review.  There was a lot of
overlap between that and Stephen's review.

On 9 June 2015 at 13:59, Kathleen Moriarty
<[email-masked]> wrote:
> It seems to me that authentication relies on TLS.  Maybe stating this
> explicitly would address the concern?  Is there a reason this should be
> in the ALPN header(I'm not sure of that, just asking)?

We're not actually authenticating this stuff.  As I noted in my other
response, this is a promise that the client makes and one that the
proxy cannot enforce (because, TLS).  So the real uses for this header
field are: prioritization (move connections from slow and fat pipes to
fast and thin pipes, maybe), or early and cleaner denial.

The latter allows the proxy to quickly generate an HTTP status code
without having to do DPI or whatever other eldritch horrors they
currently are forced to do to recognize and deny things they don't
want.

The WebRTC case is interesting, because you can actually have some
assurance about the trustworthiness of the header field.  If you trust
the browsers, that is (though I'm not advocating that, browser people
are the most untrustworthy).

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From: "Kathleen Moriarty" <[email-masked]>
Date: Tue, 09 Jun 2015 20:59:49 +0000

Kathleen Moriarty has entered the following ballot position for
draft-ietf-httpbis-tunnel-protocol-04: Discuss

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DISCUSS:
----------------------------------------------------------------------

The SecDir review called out an important point on authentication &
authorization for 

http://www.ietf.org/mail-archive/web/secdir/current/msg05748.html

The SecDir review has the the fuller set of questions.  Here is the
summary:
   "The draft never says what the proxy should do if the client makes
one claim
   in the ALPN header, but then does something different (including
using different
   ALPNs in encapsulated TLS negotiations). Seems like it should.

   Also, the draft seems to suggest that it is okay to use the ALPN for
policy/
   authorization decisions. This is unreliable from a security
perspective. At minimum,
   I think the draft should explicitly call this out."  

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COMMENT:
----------------------------------------------------------------------

I support Stephen's discuss and comments.

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From: Kathleen Moriarty <[email-masked]>
Date: Wed, 10 Jun 2015 02:26:11 +0000

Hi Martin,

On Tue, Jun 9, 2015 at 6:26 PM, Martin Thomson <[email-masked] <mailto:[email-masked]>> wrote:
Hi Kathleen,

Yes, thank you for your response.  I'm sorry you didn't see my No Objection before responding to this as I did see the discussion and the responses shortly after issuing the discuss and changed it.

Thanks for your work on this draft.
Kathleen 

-- 

Best regards,
Kathleen