On 06/06/18 23:31, Peter Eisentraut wrote:
On 6/6/18 16:26, Heikki Linnakangas wrote:
On 06/06/18 23:20, Peter Eisentraut wrote:
Aren't we attacking this on the wrong level? We are here attempting to
prevent a SCRAM-SHA-256-PLUS -> SCRAM-SHA-256 downgrade, but we are not
preventing a SCRAM-SHA-256-PLUS -> anything-else downgrade.
The latest patch does prevent that, too. That was my complaint at
https://www.postgresql.org/message-id/030284cc-d1d6-ce88-b677-a814f61c1880%40iki.fi,
but it's been fixed now. (Or if you see a case where it still isn't,
that's a bug.)
OK, that would do, but we don't do anything about a SCRAM-SHA-256 ->
anything-else downgrade. Instead of tying this to the channel binding,
should we tie it to the authentication type?
That would certainly be good. We've always had that problem, even with
md5 -> plaintext password downgrade, and it would be nice to fix it.
It's quite late in the release cycle already, do you think we should
address that now? I could go either way..
What should the option look like? Perhaps something like:
allowed_authentication_methods=md5,SCRAM-SHA-256,SCRAM-SHA-256-PLUS
That would not be very user-friendly, though.
- Heikki
