On Thu, May 17, 2018 at 09:48:54PM +0900, Michael Paquier wrote: > On Wed, May 16, 2018 at 09:09:22PM -0400, Bruce Momjian wrote: > > On Thu, May 17, 2018 at 09:56:49AM +0900, Michael Paquier wrote: > >> On Wed, May 16, 2018 at 08:20:49PM -0400, Bruce Momjian wrote: > >>> SCRAM-with-binding is the first password method that attempts to avoid > >>> man-in-the-middle attacks, and therefore is much less likely to be able > >>> to trust what the endpoints supports. I think it is really the > >>> channel_binding_mode that we want to control at the client. The lesser > >>> modes are much more reasonable to use an automatic best-supported > >>> negotiation, which is what we do now. > >> > >> Noted. Which means that the parameter is ignored when using a non-SSL > >> connection, as well as when the server tries to enforce the use of > >> anything else than SCRAM. > > > > Uh, a man-in-the-middle could prevent SSL or ask for a different > > password authentication method and then channel binding would not be > > used. I think when you say you want channel binding, you have to fail > > if you don't get it. > > I am not exactly sure what is the result we are looking for here, so I > am adding for now an open item which refers to this part of the thread. > Please note that I am fine to spend cycles if needed to address any > issues and/or concerns. Let's the discussion continue for now.
Agreed, and I just posted a more detailed email about when authentication downgrades are possible. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + As you are, so once was I. As I am, so you will be. + + Ancient Roman grave inscription +
