Re: pg_cryptohash_final possible out-of-bounds access (per Coverity)

At Wed, 10 Feb 2021 12:13:44 +0900 (JST), Kyotaro Horiguchi <horikyota(dot)ntt(at)gmail(dot)com> wrote in
> At Tue, 9 Feb 2021 22:01:45 -0300, Ranier Vilela <ranier(dot)vf(at)gmail(dot)com> wrote in
> > Hi Hackers,
> >
> > Per Coverity.
> >
> > Coverity complaints about pg_cryptohash_final function.
> > And I agree with Coverity, it's a bad design.
> > Its allows this:
> >
> > #define MY_RESULT_LENGTH 32
> >
> > function pgtest(char * buffer, char * text) {
> > pg_cryptohash_ctx *ctx;
> > uint8 digest[MY_RESULT_LENGTH];
> >
> > ctx = pg_cryptohash_create(PG_SHA512);
> > pg_cryptohash_init(ctx);
> > pg_cryptohash_update(ctx, (uint8 *) buffer, text);
> > pg_cryptohash_final(ctx, digest); // <-- CID 1446240 (#1 of 1):
> > Out-of-bounds access (OVERRUN)
> > pg_cryptohash_free(ctx);
> > return
> > }
> >
> > Attached has a patch with suggestions to make things better.
>
> I'm not sure about the details, but it looks like broken.
>
> make complains for inconsistent prototypes abd cryptohahs.c and sha1.c
> doesn't seem to agree on its interface.

Sorry, my messages was broken.

make complains for inconsistent prototypes, and cryptohahs.c and
sha1.c don't seem to agree on the interface of pg_sha1_final.

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center