Re: [PATCH v2] hex2bin: make the function hex_to_bin constant-time

From: Andy Shevchenko
Date: Wed May 04 2022 - 05:22:11 EST


On Wed, May 04, 2022 at 04:57:35AM -0400, Mikulas Patocka wrote:
> On Wed, 4 May 2022, Stafford Horne wrote:
> > On Mon, Apr 25, 2022 at 08:07:48AM -0400, Mikulas Patocka wrote:

...

> > Just a heads up it seems this patch is causing some instability with crypto self
> > tests on OpenRISC when using a PREEMPT kernel (no SMP).
> >
> > This was reported by Jason A. Donenfeld as it came up in wireguard testing.
> >
> > I am trying to figure out if this is an OpenRISC PREEMPT issue or something
> > else.

> That patch is so simple that I can't imagine how could it break the
> curve25519 test. Are you sure that you bisected it correctly?

Can you provide a test cases for hex_to_bin()?

--
With Best Regards,
Andy Shevchenko