Subject: Re: Compatibility Issues with Npgsql and .NET Framework 3.5 after Upgrading to PostgreSQL 16.3

From: Daniel Gustafsson <[email-masked]>
Date: Tue, 29 Oct 2024 12:01:26 +0100

> On 29 Oct 2024, at 04:25, 馬　騰飛 <[email-masked]> wrote:
> 
> Thank you very much for your reply. 
> However, after installing PostgreSQL 16.4, our server still encounters the following error when connecting to the database, just like with version 16.3:
> “Only AuthenticationClearTextPassword and AuthenticationMD5Password supported for now. Received: 10”.
> Could you please advise how to resolve this error? Should we also update Npgsql? If Npgsql needs to be updated, to which version should we update it?

I don't know the first thing about Npgsql so I can't offer any advice, but it
sounds like the problems is that the server wants to use SCRAM passwords and
your version of npgsql only support cleartext and md5.  Changing the METHOD in
pg_hba.conf to md5 could fix the immediate problem perhaps but upgrading to a
version that support SCRAM seems the most appropriate (especially since md5
passwords are likely going away soon).

--
Daniel Gustafsson

---

From: Adrian Klaver <[email-masked]>
Date: Tue, 29 Oct 2024 09:06:12 -0700

> passwords are likely going away soon).

Potential issue with above per:

https://www.postgresql.org/docs/current/auth-password.html

"To ease transition from the md5 method to the newer SCRAM method, if 
md5 is specified as a method in pg_hba.conf but the user's password on 
the server is encrypted for SCRAM (see below), then SCRAM-based 
authentication will automatically be chosen instead."

Therefore a roles password could still be in SCRAM. You would need to 
change the actual passwords also.

According to the issue below Npgsql supports SCRAM:

https://github.com/npgsql/npgsql/issues/5593

Which translates into Npgsql 3.2.7:

https://github.com/npgsql/npgsql/releases/tag/v3.2.7

-- 
Adrian Klaver
[email-masked]