Re: [TLS] 0-RTT, server Application Data, and client Finished

2016-01-28 Thread David Benjamin
On Wed, Jan 27, 2016 at 2:44 PM Ilari Liusvaara 
wrote:

> On Wed, Jan 27, 2016 at 07:28:47PM +, David Benjamin wrote:
> > On Tue, Jan 26, 2016 at 10:32 PM Martin Thomson <
> martin.thom...@gmail.com>
> > wrote:
> > >
> > > I get your point, but I don't see that as a simplification.  In my
> > > mind, post-handshake client authentication doesn't happen.  Or, I
> > > don't see it being commonplace.
> >
> > But the only cases where this flow is useful (server sends non-zero
> > unauthenticated bytes at t=0.5 before the authenticated bytes at t=1.5)
> has
> > all the same pitfalls of mid-stream auth (specifically that the stream's
> > authentication switches partway through), so I don't see what avoiding
> > mid-stream auth is supposed to gain.
>
> I don't think the two situations have the same problems:
> - "Server 0-RTT" has _recipient_ identity change.
> - "Dynamic reauth" has _sender_ identity change.
>
> You have more concrete examples of things going wrong with "server
> 0-RTT"? Because I have major problems coming up with troublesome
> cases.


The client also has some 0-RTT data which, in the server 0-RTT case, the
server reports was accepted and processed. That all is associated with the
first identity rather than the second. So I believe we have sender identity
change in both cases.

David
___
TLS mailing list
TLS@ietf.org
https://www.ietf.org/mailman/listinfo/tls


Re: [TLS] 0-RTT, server Application Data, and client Finished

2016-01-28 Thread Ilari Liusvaara
On Thu, Jan 28, 2016 at 05:36:22PM +, David Benjamin wrote:
> On Wed, Jan 27, 2016 at 2:44 PM Ilari Liusvaara 
> wrote:
> 
> > On Wed, Jan 27, 2016 at 07:28:47PM +, David Benjamin wrote:
> > > On Tue, Jan 26, 2016 at 10:32 PM Martin Thomson <
> > martin.thom...@gmail.com>
> >
> > I don't think the two situations have the same problems:
> > - "Server 0-RTT" has _recipient_ identity change.
> > - "Dynamic reauth" has _sender_ identity change.
> >
> > You have more concrete examples of things going wrong with "server
> > 0-RTT"? Because I have major problems coming up with troublesome
> > cases.
> 
> 
> The client also has some 0-RTT data which, in the server 0-RTT case, the
> server reports was accepted and processed. That all is associated with the
> first identity rather than the second. So I believe we have sender identity
> change in both cases.

The 0-RTT being sent under different identity than the application data
does involve sending identity change, but what does it have to do with
"server 0-RTT"? The client could do that (and run into trouble with
badly designed protocols) without "server 0-RTT".


-Ilari

___
TLS mailing list
TLS@ietf.org
https://www.ietf.org/mailman/listinfo/tls