[openssl-project] Proposed vote text for the SSL_CB_HANDSHAKE_START change

[Kurt Roeckx]

On Thu, Jan 31, 2019 at 02:19:28PM -0600, David Benjamin wrote:
> On Thu, Jan 31, 2019 at 2:01 PM Matt Caswell <matt at openssl.org> wrote:
> 
> >
> > On 31/01/2019 18:50, David Benjamin wrote:
> > > We will see if this damage turns out fatal for KeyUpdate, but OpenSSL
> > can at
> > > least help slow its spread by issuing a fix
> >
> > That's precisely what PR 8096 does.
> >
> >
> > > As a heuristic for API design: if the caller needs to know the
> > implementation
> > > details of OpenSSL to understand what this API does, the API is no good.
> > > Existing code cannot possibly predict how OpenSSL's implementation will
> > evolve
> > > over time, so there is no way to use such an API in a future-proof way.
> > Do not
> > > introduce such APIs.
> >
> > The info callback has been around a *long* time. In fact OpenSSL did not
> > introduce it at all - we inherited it from SSLeay. Arguments about whether
> > it is
> > a good API or not don't help the issue at hand. The API exists,
> > applications use
> > it, and so (for now at least) we continue to support it.
> >
> > Given that it already existed we had to make a decision about how it was
> > going
> > to work in the presence of TLSv1.3. We did what we believed to be the
> > correct
> > thing at the time. The changes were pretty minimal and we tried to keep
> > things
> > as close to what existing users of the callback would expect. It turns out
> > we
> > got it wrong.
> >
> 
> Right, but SSL_CB_POST_HANDSHAKE_START and SSL_CB_POST_HANDSHAKE_END are
> new. It seems best to just omit it, so OpenSSL is not tied to the nebulous
> notion of "post-handshake exchange".
> 
> I.e. don't bracket post-handshake things with START/END at all.

Matt, do you have any comment on this? Can we go forward with
this?


Kurt