On 6/28/18 09:35, Magnus Hagander wrote:
> No, we absolutely still have SCRAM channel binding.
>
> *libpq* has no way to *enforce* it, meaning it always acts like our
> default SSL config which is "use it if available but if it's not then
> silently accept the downgrade". From a security perspective, it's just
> as bad as our default ssl config, but unlike ssl you can't configure a
> requirement in 11.
Isn't this similar to what happened whenever we added a new or better
password method? A MITM that didn't want to bother cracking MD5 could
just alter the stream and request "password" authentication. Same with
MD5->SCRAM, SCRAM->SCRAM+CB, and even a hypothetical future change in
the SCRAM hashing method. Clearly, we need a more comprehensive
solution for this.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services