From: Johannes Goetzfried Subject: Re: [PATCH] crypto: twofish-avx - remove useless instruction Date: Fri, 6 Jul 2012 02:13:00 +0200 Message-ID: <20120706001300.GF2091@kronos.redsun> References: <20120705184358.GE2091@kronos.redsun> <20120705234612.GD29301@khazad-dum.debian.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Herbert Xu , linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org To: Henrique de Moraes Holschuh Return-path: Received: from moutng.kundenserver.de ([212.227.126.171]:50305 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932264Ab2GFANH (ORCPT ); Thu, 5 Jul 2012 20:13:07 -0400 Content-Disposition: inline In-Reply-To: <20120705234612.GD29301@khazad-dum.debian.net> Sender: linux-crypto-owner@vger.kernel.org List-ID: On Thu, Jul 05, 2012 at 08:46:12PM -0300, Henrique de Moraes Holschuh wrote: > Is it useless, or is it there to harden against some side-channel > attack? When writing this implementation, I first had a different approach with more data getting read in and I just forgot to delete this instruction in the end. The instruction didn't have any purpose regarding side-channel attacks. In the decryption routine the instruction has been correctly deleted in the same place.