Re: Fetch channel binding digest explicitly with OpenSSL 3.0 and later

On Wed, Aug 12, 2026 at 10:20:33AM +0900, Michael Paquier wrote:
> Now I think that this patch should be reworked in a style closer to
> what has been done in 1f3b9bb109b8 and b91f79cd08ab:
> - Keep the variable declarations at the top of each function. For
> example algo_type is shared between the pre-3.0 block and the post-3.0
> block. No need for two declarations.
> - The #if parts work as the way as the curly brackets, let's remove
> one level of indentation. Your patch makes the whole diff harder to
> parse and the pre-3.0 code is still the same.
> - Minimization of the diffs by planting more #if blocks. Here I am
> looking at the EVP_MD_free() calls. Let's minimize the duplicated
> libpq_append_conn_error() and elog(ERROR) calls in the final result.

As this part was itching me, I have taken a shot at simplifying the
patch, and it looks much better once adapted among these lines. The
EVP_MD_free() feel slightly annoying, but they're isolated enough that
they don't matter to me. A second thing is the const marker for
EVP_MD, which avoids some casts or some unconstify(). At the end that
feels like the best thing to do.

Attached is the refined version. Comments and/or objections?
--
Michael