Re: [TLS] Removing restriction on cross-domain resumption

[Jeffrey Walton <[e-mail]>]

On Wed, Sep 13, 2017 at 5:57 PM, Victor Vasiliev <[e-mail]> wrote:
> Currently, TLS 1.3 specification forbids resuming the session if SNI values
> do not match.  This is inefficient in multiple cases, for example, if you
> have a wildcard domain cert, and the user is likely to visit multiple
> subdomains over a longer timespan, so there is no existing connection to
> pool on (or it's impossible to pool because of different IP addresses).
>
> Last time we discussed this,
>   https://www.ietf.org/mail-archive/web/tls/current/msg21655.html
> no one has pointed out a good security reason why this should be forbidden.

The current models uses origins as a boundary, so they are different
security contexts.

A related twist is, the boundary is established at layer 7, but layer
3/4 has no knowledge of it.

The DBOUND working group was not able to produce a deliverable. There
is no general purpose way to establish those boundaries.

To play devil's advocate, will the TLS stack need to keep a copy of
the certificate or authorized origins (an origin group?) for future
connections?

Jeff