Re: [PATCH] user mapping extension to pg_ident.conf

Magnus Hagander <magnus(at)hagander(dot)net> writes:
>> Yup, you would need a protocol change that would allow the client to
>> change its mind about what the username was after it got the auth
>> challenge. And then what effects does that have on username-sensitive
>> pg_hba.conf decisions? We go back and change our minds about the
>> challenge type, perhaps? The whole thing seems like a nonstarter to me.

> "challenge type"? Not sure I understand what you are referring to here.

The point is that pg_hba.conf allows the selection of auth method to
depend on username. What happens if, after being told auth method is
(say) Kerberos, the client comes back and wants to use a different
username that should have resulted in a different auth method according
to pg_hba.conf? It's not hard to construct scenarios where that would
be seen as a security breach.

regards, tom lane