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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 6C159C433ED for ; Thu, 8 Apr 2021 15:30:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2C8E361107 for ; Thu, 8 Apr 2021 15:30:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231934AbhDHPa1 (ORCPT ); Thu, 8 Apr 2021 11:30:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:48150 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231630AbhDHPaY (ORCPT ); Thu, 8 Apr 2021 11:30:24 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C927961108; Thu, 8 Apr 2021 15:30:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617895813; bh=ObSC29eEIMMYQErKHg+/HPZxQbS/5NvRx9UKVloQqZs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fKoN8GMHJU6D5ourC8Tj4kmhM+ANhLHVHkFY26bU6rNFfEQkfHfZ195bG7NveJi5W OqxLiP68H5znnvcagrwb19JWVDBdyI7Na7UJEbRByq+TveIgfayqnZMEXuNt+v+V+z Rf7bDUq2cUpr9RfvpSKR4LMCZCuqkCufhb7xNvtUGxEGP067tQwpT8dPf+f3ncgeiv AuY37KNIERk2uH3SAcGksjiWCi9JWKrBhVXvu9V4+igKSUtVgfOnnK+o/WWWvp7c9W AGNQzJVt7HKYjRRk/N+lPB1/lAJUKm9wBdQULenJp/1ZiB1lCtOc1E6W0FWbX18FG+ 6axkT+V5BGULg== Date: Thu, 8 Apr 2021 08:30:11 -0700 From: Eric Biggers To: Chris von Recklinghausen Cc: 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 v5 1/1] use crc32 instead of md5 for hibernation e820 integrity check Message-ID: References: <20210408131506.17941-1-crecklin@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210408131506.17941-1-crecklin@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 08, 2021 at 09:15:06AM -0400, Chris von Recklinghausen wrote: > Suspend fails on a system in fips mode because md5 is used for the e820 > integrity check and is not available. Use crc32 instead. > > This patch changes the integrity check algorithm from md5 to > crc32. This integrity check is used only to verify accidental > corruption of the hybernation data and is not intended as a > cryptographic integrity check. > Md5 is overkill in this case and also disabled in FIPS mode because it > is known to be broken for cryptographic purposes. > > Fixes: 62a03defeabd ("PM / hibernate: Verify the consistent of e820 memory map > by md5 digest") > > Tested-by: Dexuan Cui > Reviewed-by: Dexuan Cui > Signed-off-by: Chris von Recklinghausen > --- > v1 -> v2 > bump up RESTORE_MAGIC > v2 -> v3 > move embelishment from cover letter to commit comments (no code change) > v3 -> v4 > add note to comments that md5 isn't used for encryption here. > v4 -> v5 > reword comment per Simo's suggestion > > arch/x86/power/hibernate.c | 35 +++++++++++++++++++---------------- > 1 file changed, 19 insertions(+), 16 deletions(-) > > diff --git a/arch/x86/power/hibernate.c b/arch/x86/power/hibernate.c > index cd3914fc9f3d..b56172553275 100644 > --- a/arch/x86/power/hibernate.c > +++ b/arch/x86/power/hibernate.c > @@ -55,31 +55,31 @@ int pfn_is_nosave(unsigned long pfn) > } > > > -#define MD5_DIGEST_SIZE 16 > +#define CRC32_DIGEST_SIZE 16 > > struct restore_data_record { > unsigned long jump_address; > unsigned long jump_address_phys; > unsigned long cr3; > unsigned long magic; > - u8 e820_digest[MD5_DIGEST_SIZE]; > + u8 e820_digest[CRC32_DIGEST_SIZE]; > }; > > -#if IS_BUILTIN(CONFIG_CRYPTO_MD5) > +#if IS_BUILTIN(CONFIG_CRYPTO_CRC32) Should CONFIG_CRYPTO_CRC32 be getting selected from somewhere? If that is too hard because it would pull in too much of the crypto API, maybe using the library interface to CRC-32 (lib/crc32.c) would be a better fit? - Eric