Re: Proposed patch for key managment - Mailing list pgsql-hackers

On Sat, Dec  5, 2020 at 11:39:18AM +0900, Michael Paquier wrote:
> On Fri, Dec 04, 2020 at 09:08:03PM -0500, Bruce Momjian wrote:
> > Here is an updated patch to handle the new hash API introduced by
> > commit 87ae9691d2.
> 
> +       if (!ossl_initialized)
> +       {
> +#ifdef HAVE_OPENSSL_INIT_SSL
> +               OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL);
> +#else
> +               OPENSSL_config(NULL);
> +               SSL_library_init();
> +               SSL_load_error_strings();
> +#endif
> +               ossl_initialized = true;
> This is a duplicate of what's done in be-secure-openssl.c, and it does
> not strike me as a good idea to do that potentially twice.

Yeah, I kind of wondered about that.  In fact, the code from the
original patch would not compile so I got this init code from somewhere
else. I have now removed it and it works fine.  :-)

> git diff --check complains.

Uh, can you be more specific?  I don't see any output from that command.

> +extern bool pg_HMAC_SHA512(const uint8 *key,
> +                           const uint8 *in, int inlen,
> +                           uint8 *out);
> I think that the split done in this patch makes the HMAC handling in
> the core code messier:
> - SCRAM makes use of HMAC internally, and we should try to use the
> HMAC of OpenSSL if building with it even for SCRAM.
> - For the first reason, I think that we should also have a fallback
> implementation.
> - This API layer should not depend directly on the SHA2 used (SCRAM
> uses SHA256 with HMAC).
> FWIW, I got plans to work on that once I am done with the business
> around MD5 and OpenSSL.

Uh, I just kind of kept all that code and didn't modify it.  It would be
great if you can help me improve it.  I will be using the hash code for
the command-line tool that alters the passphrase, so having that in
common/ does help me.

> The refactoring done with the ciphers moved from pgcrypto to
> src/common/ should be a separate patch.  In short, it would be good to

Uh, I am kind of unclear exactly what was done there since I just took
that part of the patch unchanged.

> rework this patch and split it into pieces that are independently
> useful.  This would make the review much easier as well.

I can break out the -R/file descriptor passing part as a separate patch,
and have the ssl_passphrase_command use that, but that's the only part I
know can be useful on its own.

Since the patch is large, I found a way to push the branch to git and
how to make a download link that tracks whatever I push to the 'key'
branch on my github account.  Here is the updated patch link:

    https://github.com/postgres/postgres/compare/master...bmomjian:key.diff

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

  The usefulness of a cup is in its emptiness, Bruce Lee