From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22F89C433B4 for ; Fri, 9 Apr 2021 16:56:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 005CD610CC for ; Fri, 9 Apr 2021 16:56:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234177AbhDIQ4Y convert rfc822-to-8bit (ORCPT ); Fri, 9 Apr 2021 12:56:24 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([185.58.86.151]:47292 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234174AbhDIQ4X (ORCPT ); Fri, 9 Apr 2021 12:56:23 -0400 Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-227-DriuMqMLOW-eHfKXrEcolA-1; Fri, 09 Apr 2021 17:56:06 +0100 X-MC-Unique: DriuMqMLOW-eHfKXrEcolA-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 9 Apr 2021 17:56:05 +0100 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.012; Fri, 9 Apr 2021 17:56:05 +0100 From: David Laight To: 'Chris von Recklinghausen' , "ardb@kernel.org" , "simo@redhat.com" , "rafael@kernel.org" , "decui@microsoft.com" , "linux-pm@vger.kernel.org" , "linux-crypto@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH v4 1/1] use crc32 instead of md5 for hibernation e820 integrity check Thread-Topic: [PATCH v4 1/1] use crc32 instead of md5 for hibernation e820 integrity check Thread-Index: AQHXLGR5Apl1dLUk2U+lDfr8mZtTlqqsaSNw Date: Fri, 9 Apr 2021 16:56:05 +0000 Message-ID: <6be63531313d46caa7161697bf240dfc@AcuMS.aculab.com> References: <20210408104629.31357-1-crecklin@redhat.com> In-Reply-To: <20210408104629.31357-1-crecklin@redhat.com> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org From: Chris von Recklinghausen > Sent: 08 April 2021 11:46 > > Suspend fails on a system in fips mode because md5 is used for the e820 > integrity check and is not available. Use crc32 instead. > > Prior to this patch, MD5 is used only to create a digest to ensure integrity of > the region, no actual encryption is done. This patch set changes the integrity > check to use crc32 instead of md5 since crc32 is available in both FIPS and > non-FIPS modes. > > Note that the digest is only used as an integrity check. No actual encryption > is done. If crc32 is good enough, would a 1's compliment sum be good enough? It is likely to be faster to calculate and not need special functions be built into the kernel at all. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)