Re: postgres_fdw, dblink: Validate use_scram_passthrough values

Ayush Tiwari <ayushtiwari.slg01@gmail.com>

From: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
To: Fujii Masao <masao.fujii@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2026-05-27T16:00:07Z
Lists: pgsql-hackers
Hi,

On Wed, 27 May 2026 at 20:12, Fujii Masao <masao.fujii@gmail.com> wrote:

> Hi,
>
> The use_scram_passthrough option in postgres_fdw and dblink is
> intended to accept only boolean values. However, unlike other boolean
> options such as keep_connections, its value is not currently
> validated.
>
> As a result, invalid values are accepted unexpectedly, for example:
>
> CREATE SERVER test_server
>   FOREIGN DATA WRAPPER postgres_fdw
>   OPTIONS (use_scram_passthrough 'invalid');
>
> Attached patch updates postgres_fdw and dblink to validate
> use_scram_passthrough values and throw an error for invalid input.


Thanks for the patch, Fujii-san!

I applied it on HEAD and it looks good to me.  The change looks consistent
with the existing validation of other boolean FDW options.

I also checked the behavior manually for both CREATE SERVER and CREATE USER
MAPPING in postgres_fdw and dblink.  Invalid values are now rejected with:

    ERROR:  use_scram_passthrough requires a Boolean value

Regards,
Ayush