Subject: Re: [Unbearable] [TBPROTO] clarification of renego and EKM 2nd parag

From: =JeffH <[email-masked]>
Date: Tue, 29 Nov 2016 14:55:17 -0800

>  >   and a mechanism
 >  >    preventing a TokenBindingMessage from being split across the
 >  >    renegotiation boundary.
 >
 > Nick refers...

ah yes, this stuff is in that long "Renegotiation info extension" thread 
(and associated threads) on the list it seems.

here's a relevant msg from nick (nharper) from that thread...

<https://www.ietf.org/mail-archive/web/unbearable/current/msg00691.html>

..though I do not find on the list where Nick discussed the below wrt 
the the possibility of the TB message (which is included in an app-layer 
msg, which is conveyed in a TLS application_data msg) being "split" 
across a renego boundary.

 > to the fact that an application_data message can be
 > fragmented, with some fragments delivered before renegotiation and
 > others after renegotiation. If one fragmented TB message is therefore
 > sent both before and after a renegotiation, it's not clear which EKM
 > it's using (probably from before the renegotiation, but then it's not
 > the current one). Nick's solution is to prohibit such splitting of TB
 > messages across the renegotiation boundary.

though, the language he apparently proposed for both HTTPSTB and TBPROTO 
is here..

https://github.com/TokenBinding/Internet-Drafts/commit/99e6b49392b417cd23c5341fd57f720e5e2575ee

..however the explanation above is more understandable due to including 
some details.

=JeffH

---

From: =JeffH <[email-masked]>
Date: Tue, 29 Nov 2016 16:14:45 -0800

Oh, and because DMARC and (ietf) mailing lists do not play well 
together, I didn't see the last couple replies to this thread from Nick 
and Andrei until just now (after I'd sent my reply prior to this one).

fyi/fwiw...

=JeffH