Re: Modern SHA2- based password hashes for pgcrypto

Hi,

On 2025-04-05 19:22:58 +0200, Alvaro Herrera wrote:
> I have pushed this now, hoping it won't explode.

I have a WIP patch that adds gcc specific allocator attributes for palloc et
al. Just rebased that. It warns on the new code as follows:

[1489/1804 42  82%] Compiling C object contrib/pgcrypto/pgcrypto.so.p/crypt-sha.c.o
../../../../../home/andres/src/postgresql/contrib/pgcrypto/crypt-sha.c: In function 'px_crypt_shacrypt':
../../../../../home/andres/src/postgresql/contrib/pgcrypto/crypt-sha.c:605:13: warning: pointer 'cp' may be used after 'pfree' [-Wuse-after-free]
  605 |         *cp = '\0';
      |         ~~~~^~~~~~
../../../../../home/andres/src/postgresql/contrib/pgcrypto/crypt-sha.c:533:9: note: call to 'pfree' here
  533 |         pfree(s_bytes);
      |         ^~~~~~~~~~~~~~

And it sure seems to have a point.  I'm surprised this isn't causing wider
issues...

Greetings,

Andres Freund