>Thanks again for your review! The PR is on Github 
> and will be incorporated into a new
>version of the document that addresses both your comments and those by Yaron 

Looks good.



On Thu, Sep 19, 2019 at 11:29 PM Christer Holmberg 
<christer.holmb...@ericsson.com<mailto:christer.holmb...@ericsson.com>> wrote:

>Some answers to your questions inline. I'm not sure further changes along the 
>lines suggested here are needed, but I'm open to arguments that point in that 

I am mostly fine with your answers. Just a couple of comments inline still.



>>>> Can the mechanism be used also for DTLS?
>>> I think the answer is yes. I don't see any reason to disallow the use of 
>>> Exported Authenticators in DTLS.
>> Would it be useful to clarify that?
> Going through what the modified text would look like, it seems like a 
> substantial amount of re-writing (even the title!) for what amounts to an 
> unclear use case.
> Keeping in mind that DTLS 1.3 hasn't been finalized and doesn't directly 
> define exporters, I'm disinclined to define how EAs would work with DTLS. If 
> someone
> has a strong use case for EA in DTLS, it may be worth considering it.

Would it then be useful with a statement saying that it might be possible to 
use exporters also with DTLS, but that such usage is outside the scope of the 
document and needs to be specified in a separate document?

I added a line to this effect.



>>>> The documents talk about additional certificates. If I only have one 
>>>> additional
>>>> certificate, can I use that for multiple authenticators throughout the TLS
>>>> session?
>>> Yes, there is nothing disallowing the creation of multiple exported 
>>> authenticators with the same certificate.
>> Would it be useful to clarify that?
> I'm not convinced this is a realistic use case. Since exported authenticators 
> are based on the exporter, there is no inherent ordering.
> If you re-authenticate with the same certificate, there's nothing asserting 
> freshness of the second certificate. Is there something in
> the text that suggests that using a certificate multiple times is disallowed? 
> If there's no suggestion that this is not possible that
> needs to be corrected, I don't see the benefit of calling out this specific 
> use case.

I don't think there is any text suggesting that it is disallowed. But, if you 
don't think it is a realistic use case I'll take your word for it :)



>>>> Section 3 says: "The authenticator request is a structured message that 
>>>> can be
>>>> created..." Section 4 says: "The authenticator is a structured message 
>>>> that can
>>>> be exported..."
>>>> In the 2nd paragraph of Section 4 it is stated that "authenticator" is sent
>>>> based on an "authenticator request". I wonder if that could be stated 
>>>> already
>>>> in the beginning of Section 4, to further clarify the difference between 
>>>> them.
>>>> E.g.,
>>>> "The authenticator is a structured message, triggered by an authenticator
>>>> request, that can be exported from either party of a TLS connection."
>>> The issue is that servers can generate spontaneous exported authenticators 
>>> without
>>> an authenticator request.
>> Where is this written? Did I miss it?
> Section 4:
>   An authenticator message can be constructed by either the client or
>   the server given an established TLS connection, a certificate, and a
>   corresponding private key.  Clients MUST NOT send an authenticator
>   without a preceding authenticator request; for servers an
>   authenticator request is optional.  For authenticators that do not
>   correspond to authenticator requests, the certificate_request_context
>   is chosen by the server.

Ok. Looks good.



TLS mailing list

Reply via email to