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

Thank you very much for your response.
After changing the "password_encryption" option to "md5" in the postgresql.conf file, the server can now successfully connect to the database.
Thanks again for your help.

-----Original Message-----
From: Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>
Sent: Wednesday, October 30, 2024 12:06 AM
To: Daniel Gustafsson <daniel(at)yesql(dot)se>; 馬　騰飛 <ma-tengfei(at)nec(dot)cn>
Cc: pgsql-general(at)lists(dot)postgresql(dot)org
Subject: Re: Compatibility Issues with Npgsql and .NET Framework 3.5 after Upgrading to PostgreSQL 16.3

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On 10/29/24 04:01, Daniel Gustafsson wrote:
>> On 29 Oct 2024, at 04:25, 馬　騰飛 <ma-tengfei(at)nec(dot)cn> 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).

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

>
> --
> Daniel Gustafsson
>
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com