From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753456Ab3BKITO (ORCPT ); Mon, 11 Feb 2013 03:19:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:3573 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752968Ab3BKITN (ORCPT ); Mon, 11 Feb 2013 03:19:13 -0500 Message-ID: <5118A979.4090807@redhat.com> Date: Mon, 11 Feb 2013 09:19:05 +0100 From: Daniel Borkmann User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Greg KH CC: Joe Perches , akpm@linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] lib: memcmp_nta: add timing-attack secure memcmp References: <1360538650.2028.2.camel@joe-AO722> <51182DAB.1030708@redhat.com> <20130210235057.GA5485@kroah.com> In-Reply-To: <20130210235057.GA5485@kroah.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/11/2013 12:50 AM, Greg KH wrote: > On Mon, Feb 11, 2013 at 12:30:51AM +0100, Daniel Borkmann wrote: >> On 02/11/2013 12:24 AM, Joe Perches wrote: >>> On Sun, 2013-02-10 at 23:00 +0100, Daniel Borkmann wrote: >>>> add memcmp_nta ({n}o {t}iming {a}ttacks) >>> >>> Why should this be in the kernel? >> >> As the commit message already says, so that current or future (e.g.) network >> protocol code or modules can make use of this when dealing with cryptographic >> hash comparisons. > > Do we have any in-kernel users that need this? If not, then don't add > it now, but rather, add it when we actually have a user. We almost > never add kernel functions that no one calls, that would be just > wasteful. Agreed, I think there are users for it. But I'll resend a set at a later point in time, after some more testing and verifying. Thanks, Greg.