Messages in this thread | | | From | Andrey Ryabinin <> | Date | Thu, 24 Nov 2016 15:20:08 +0300 | Subject | Re: [PATCH 2/2] MPI: Fix mpi_powm() when exponent is 0 and the result has no limbs |
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2016-11-24 14:33 GMT+03:00 David Howells <dhowells@redhat.com>: > Andrey Ryabinin <ryabinin.a.a@gmail.com> wrote: > >> > David Howells <dhowells@redhat.com> wrote: >> > >> >> + if (!rp) { >> >> + if (mpi_resize(res, 1) < 0) >> > >> > This is better done with RESIZE_IF_NEEDED(). >> > >> >> mpi_resize() is equal to RESIZE_IF_NEEDED(), it also checks for allocated space: >> >> int mpi_resize(MPI a, unsigned nlimbs) >> { >> .... >> if (nlimbs <= a->alloced) >> return 0; /* no need to do it */ > > Hmmm... In that case, should your patch use mpi_resize() rather than > RESIZE_IF_NEEDED()? It's a trivial case that we should perhaps weed out much > earlier (ie. reject the key if exp<2 or mod<2), but it would make the object > file slightly smaller not to do the test twice. >
Right, it could be mpi_resize(). I realized that these two functions do the exactly the same thing only after I send the patch. We could even remove RESIZE_IF_NEEDED() to not confuse people, because currently it has no users.
> David
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