From: Stephan Mueller Subject: Re: [PATCH 2/2] crypto: kpp - Add DH software implementation Date: Wed, 13 Apr 2016 11:23:27 +0200 Message-ID: <3007460.XDCGCz3pFQ@tauon.atsec.com> References: <1460457556-3117-1-git-send-email-salvatore.benedetto@intel.com> <365125038.ZIqeO5uAXD@tauon.atsec.com> <309B30E91F5E2846B79BD9AA9711D0318E80ED@IRSMSX102.ger.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: "herbert@gondor.apana.org.au" , "linux-crypto@vger.kernel.org" To: "Benedetto, Salvatore" Return-path: Received: from mail.eperm.de ([89.247.134.16]:34454 "EHLO mail.eperm.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932614AbcDMJXb (ORCPT ); Wed, 13 Apr 2016 05:23:31 -0400 In-Reply-To: <309B30E91F5E2846B79BD9AA9711D0318E80ED@IRSMSX102.ger.corp.intel.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: Am Mittwoch, 13. April 2016, 09:07:38 schrieb Benedetto, Salvatore: Hi Salvatore, > > I don't see any particular benefit in replacing this check with a lower > boundary check only. Values other than those listed are very unlikely. > Anyway, if you feel so strong about it and other people think the same I'm > OK with either check :-) Either case shouldn't harm. The kernel is not supposed to policy user decisions. It is only there to perform operations. It is allowed to enforce policies to cover known weaknesses though (hence the check for the lower boundary). So, if a user wants to use 2040 bit DH keys, what reason has the kernel to object? Note, with the advancements of quantum computers is may be likely that we all want to use very large keys for asymmetric ciphers in the not too distant future. Ciao Stephan