Re: [TLS] WGLC for draft-ietf-tls-exported-authenticator

[Roelof duToit <[e-mail]>]

Perhaps, but it still behooves us to warn implementors that a significant percentage of enterprise traffic will break with this mechanism.

> On May 9, 2018, at 3:39 AM, Martin Thomson <[e-mail]> wrote:
> 
> This isn't really a security consideration though, it's a truism.  A MitM
> can break things that depend on end-to-end integrity of the connection.
> On Wed, May 9, 2018 at 11:25 AM Roelof duToit <[e-mail]> wrote:
> 
>> If the use of the mechanism is not negotiated on the TLS level then I
> would appreciate it if the “Security Considerations” section of the draft
> could be amended to include a paragraph that warns potential implementors
> that protocol-agnostic middleboxes will break the mechanism without any
> clear failure indicators.
> 
>>> On May 8, 2018, at 8:13 PM, Martin Thomson <[e-mail]>
> wrote:
>>> 
>>> On Wed, May 9, 2018 at 2:20 AM Roelof duToit <[e-mail]> wrote:
>>> 
>>>> I understand that there is not really anything to negotiate per se, but
>>> would it not be prudent to add a TLS extension to negotiate support for
>>> exported-authenticator in the TLS layer prior to using it in the
>>> application layer?
>>> 
>>> We don't signal the potential need for exporters.  I see no reason to
>>> signal this either.  Any signaling necessary really belongs at the
> higher
>>> layer.