Re: Key management with tests

Greetings Bruce,

* Bruce Momjian (bruce@momjian.us) wrote:
> On Fri, Jan  1, 2021 at 01:07:50AM -0500, Bruce Momjian wrote:
> > On Thu, Dec 31, 2020 at 11:50:47PM -0500, Bruce Momjian wrote:
> > > I have completed the key management patch with tests created by Stephen
> > > Frost.  Original patch by Masahiko Sawada.  It requires the hex
> > > reorganization patch first.  The key patch is now 2.1MB because of the
> > > tests, so attaching it here seems unwise:
> > >
> > >     https://github.com/postgres/postgres/compare/master...bmomjian:hex.diff
> > >     https://github.com/postgres/postgres/compare/master...bmomjian:key.diff
> > >
> > > I will add it to the commitfest.  I think we need to figure out how much
> > > of the tests we want to add.
> >
> > I am getting regression test errors using OpenSSL 1.1.1d  10 Sep 2019
> > with zero-length input data (no -p), while Stephen is able for those
> > tests to pass.   This needs more research, plus I think higher-level
> > tests.
>
> I have found the cause of the failure, which I added as a C comment:
>
>     /*
>      * OpenSSL 1.1.1d and earlier crashes on some zero-length plaintext
>      * and ciphertext strings.  It crashes on an encryption call to
>      * EVP_EncryptFinal_ex(() in GCM mode of zero-length strings if
>      * plaintext is NULL, even though plaintext_len is zero.  Setting
>      * plaintext to non-NULL allows it to work.  In KW/KWP mode,
>      * zero-length strings fail if plaintext_len = 0 and plaintext is
>      * non-NULL (the opposite).  OpenSSL 1.1.1e+ is fine with all options.
>      */
>     else if (cipher == PG_CIPHER_AES_GCM)
>     {
>         plaintext_len = 0;
>         plaintext = pg_malloc0(1);
>     }
>
> All the tests pass now.  The current src/test directory is 19MB, and
> adding these tests takes it to 23MB, or a 20% increase.  That seems like
> a lot.  It is testing 128-bit and 256-bit keys --- should we do fewer
> tests, or just test 256, or use gzip to compress the tests by 50%?
> (Does every platform have gzip?)

Thanks a lot for working on this and figuring out what the issue was and
fixing it!  That's great that we got all those cases passing for you
too.

Thanks again,

Stephen