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

[Nick Sullivan <[e-mail]>]

I've put together some PRs to address the comments from last call. Comments
welcome.

Failing CertificateVerify due to MITM text:
https://github.com/tlswg/tls-exported-authenticator/pull/28

Comments from Ben Kaduk:
https://github.com/tlswg/tls-exported-authenticator/pull/26

Authenticated Denial:
https://github.com/tlswg/tls-exported-authenticator/pull/27


Nick

On Thu, May 24, 2018 at 5:54 PM Martin Thomson <[e-mail]>
wrote:

> Mike just inadvertently (?) discovered a problem with exported
> authenticators.
>
> TLS post handshake authentication provides an authenticated refusal when a
> certificate can't be found.  It turns out that the current design of the
> HTTP/2 CERTIFICATE frame might need to rely on the same capability here.
>
> The current draft doesn't really say anything about what happens.
>
> https://github.com/tlswg/tls-exported-authenticator/issues/25
>
> On Sat, May 12, 2018 at 9:59 AM Nick Sullivan <[e-mail]
> >
> wrote:
>
> > Thanks all for the comments on the draft. Let me try to summarize the
> comments and propose next steps.
>
> > Tim Hollebeek had a comment about 0 as the separator. I generally don’t
> think this is a big issue, and prefer 0 because it is a natural way to
> terminate a string. If anyone strongly disagrees, please reply to the list.
>
> > Roelof duToit raised a question about middlebox interoperability,
> specifically that the exporters will not match if the TLS connection is not
> end-to-end. There was a subsequent discussion about where to signal this
> property. Martin Thomson suggested a signaling mechanism at the application
> layer (https://github.com/httpwg/http-extensions/issues/617) and Eric
> Rescorla suggested that the fact that this could cause CertificateVerify
> failures should be called out in the document. I'll put a PR together to
> add some helpful text around debugging CertificateVerify failures to
> address Eric's suggestion.
>
> > Ben Kaduk had three points:
> > - The certificate_request_context is prone to collisions with
> post-handshake authentication and there are different spaces for the server
> and client context values. He suggested some text in Section 3 and maybe
> more explanation in Section 5.2 as well. I’ll put together a PR for this.
> > - Section 4.1 talks of the length of the exporter value in terms of the
> length of the
> > TLS PRF hash, adding that cipher suites not using TLS PRF have to define
> a hash function, but TLS 1.3 ciphersuites do not use the TLS PRF. I’ll put
> together a PR to clarify the text around this clarifying that for TLS 1.3
> cipher suites, the HDKF hash is what is meant.
> > - The “signature_algorithms_cert” extension was not incorporated into the
> draft. I’ll put together a PR for 4.2.1., 4.2.2. and 5.1. to incorporate
> this extension.
>
> > I'll have the proposed changes for the above comments ready next week.
>
> > There were also some uncontroversial suggestions that I propose merging:
> > https://github.com/tlswg/tls-exported-authenticator/pull/21
> > https://github.com/tlswg/tls-exported-authenticator/pull/22
> > https://github.com/tlswg/tls-exported-authenticator/pull/23
> > https://github.com/tlswg/tls-exported-authenticator/pull/24
>
>
> > Nick
>
>
> > On Thu, May 3, 2018 at 1:16 PM Nick Sullivan <
> [e-mail]>
> wrote:
>
> >> Does anyone have any comments about the draft, criticisms, or votes of
> support?
>
> >> Nick
>
>
> >> On Thu, May 3, 2018 at 1:12 PM Sean Turner <[e-mail]> wrote:
>
>
>
> >>> > On Apr 21, 2018, at 10:25, Sean Turner <[e-mail]> wrote:
> >>> >
> >>> >
> >>> >> On Apr 19, 2018, at 16:32, Sean Turner <[e-mail]> wrote:
> >>> >>
> >>> >> All,
> >>> >>
> >>> >> This is the working group last call for the "Exported Authenticators
> in TLS" draft available at
> https://datatracker.ietf.org/doc/draft-ietf-tls-exported-authenticator/.
> Please review the document and send your comments to the list by 2359 UTC
> on 4 April 2018.
> >>> >
> >>> > … 4 May 2018 ...
>
> >>> Just a reminder the WGLC ends tomorrow.
>
> >>> spt
> >>> _______________________________________________
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> >>> https://www.ietf.org/mailman/listinfo/tls
>
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>