From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752806AbdLENwg convert rfc822-to-8bit (ORCPT ); Tue, 5 Dec 2017 08:52:36 -0500 Received: from mail.eperm.de ([89.247.134.16]:42780 "EHLO mail.eperm.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751937AbdLENwe (ORCPT ); Tue, 5 Dec 2017 08:52:34 -0500 From: Stephan Mueller To: =?utf-8?B?xYF1a2Fzeg==?= Stelmach Cc: Krzysztof Kozlowski , robh+dt@kernel.org, Herbert Xu , "David S. Miller" , Kukjin Kim , linux-crypto@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, m.szyprowski@samsung.com, b.zolnierkie@samsung.com Subject: Re: [PATCH 3/3] crypto: exynos - Reseed PRNG after generating 2^16 random bytes Date: Tue, 05 Dec 2017 14:52:31 +0100 Message-ID: <6915204.SlqusmoAzB@tauon.chronox.de> In-Reply-To: <20171205123558.31087-4-l.stelmach@samsung.com> References: <20171205123558.31087-1-l.stelmach@samsung.com> <20171205123558.31087-4-l.stelmach@samsung.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Dienstag, 5. Dezember 2017, 13:35:58 CET schrieb Łukasz Stelmach: Hi Łukasz, > Reseed PRNG after reading 65 kB of randomness. Although this may reduce > performance, in most casese the loss is not noticable. Please add to the log that you also increase the timer-based reseed to 1 second?! Another suggestion: maybe you want to add a comment to the reseed function to indicate it is for enhanced backtracking resistance. Otherwise a lot of folks would scratch their head why such code exists in the first place. :-) Other than that: Reviewed-by: Stephan Mueller Ciao Stephan