Re: [PATCH crypto-next v2 1/3] crypto: poly1305 - add new 32 and 64-bit generic versions

Jason A. Donenfeld
2019-12-12T15:35:19Z

On Thu, Dec 12, 2019 at 4:30 PM Martin Willi <martin@strongswan.org> wrote:
> > The principle advantage of this patchset is the 64x64 code
>
> If there are platforms / code paths where this code matters, all fine.

It does matter.

>
> But the 64-bit version adds a lot of complexity because of the
> different state representation and the conversion between these states.
> I just don't think the gain (?) justifies that added complexity.

No, there's no conversion between the state representation, or any
complexity like that added.

I think if anything, the way this patch works, we wind up with
something easier to audit and look at. You can examine
poly1305-donna32.c and poly1305-donna64.c side-by-side and compare
line-by-line, as clean and isolate implementations. And this is very
well-known code too.