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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham 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 B37A0C46470 for ; Tue, 7 Aug 2018 07:32:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 73B4F2177A for ; Tue, 7 Aug 2018 07:32:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 73B4F2177A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388896AbeHGJpa (ORCPT ); Tue, 7 Aug 2018 05:45:30 -0400 Received: from mga09.intel.com ([134.134.136.24]:33808 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732805AbeHGJpa (ORCPT ); Tue, 7 Aug 2018 05:45:30 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 07 Aug 2018 00:32:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,454,1526367600"; d="scan'208";a="64116973" Received: from chenyu-desktop.sh.intel.com (HELO chenyu-desktop) ([10.239.160.116]) by orsmga006.jf.intel.com with ESMTP; 07 Aug 2018 00:32:24 -0700 Date: Tue, 7 Aug 2018 15:38:40 +0800 From: Yu Chen To: Oliver Neukum Cc: Pavel Machek , "Rafael J . Wysocki" , Eric Biggers , "Lee, Chun-Yi" , Theodore Ts o , Stephan Mueller , Denis Kenzior , linux-pm@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, "Gu, Kookoo" , "Zhang, Rui" Subject: Re: [PATCH 0/4][RFC v2] Introduce the in-kernel hibernation encryption Message-ID: <20180807073840.GA17894@chenyu-desktop> References: <20180718202235.GA4132@amd> <20180718235851.GA22170@sandybridge-desktop> <20180719110149.GA4679@amd> <20180719132003.GA30981@sandybridge-desktop> <20180720102532.GA20284@amd> <1532346156.3057.11.camel@suse.com> <20180723162302.GA4503@sandybridge-desktop> <1532590246.7411.3.camel@suse.com> <20180806075754.GA12124@chenyu-desktop> <1533550820.15815.14.camel@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1533550820.15815.14.camel@suse.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 06, 2018 at 12:20:20PM +0200, Oliver Neukum wrote: > On Mo, 2018-08-06 at 15:57 +0800, Yu Chen wrote: > > Hi Oliver, > > On Thu, Jul 26, 2018 at 09:30:46AM +0200, Oliver Neukum wrote: > > > On Di, 2018-07-24 at 00:23 +0800, Yu Chen wrote: > > > > > > > > Good point, we once tried to generate key in kernel, but people > > > > suggest to generate key in userspace and provide it to the > > > > kernel, which is what ecryptfs do currently, so it seems this > > > > should also be safe for encryption in kernel. > > > > https://www.spinics.net/lists/linux-crypto/msg33145.html > > > > Thus Chun-Yi's signature can use EFI key and both the key from > > > > user space. > > > > > > Hi, > > > > > > ecryptfs can trust user space. It is supposed to keep data > > > safe while the system is inoperative. > > > > Humm, I did not quite get the point here, let's take fscrypt > > While the system is running and the fs is mounted, your data > is as secure as root access to your machine, right? You encrypt > a disk primarily so data cannot be recovered (and altered) while > the system is not running. > > Secure Boot does not trust root fully. There is a cryptographic > chain of trust and user space is not part of it. > Okay, I see. So if we want to use secure boot mechanism for hibernation encryption, user space is trusted. > > for example, the kernel gets user generated key from user space, > > and uses per-inode nonce(random bytes) as the master key to > > do a KDF(key derivation function) on user provided key, and uses > > that key for encryption. We can also added similar mechanism > > to generate the key in kernel space but the key should be > > original from user's provided key(password derived), because > > the security boot/signature mechanism could not cover the case > > that, two different users could resume to each other's context > > because there isn't any certification during resume if it is > > on the same physical hardware. > > Please explain. You will always have to suspend the whole machine > with all tasks of all users. And STD with Secure Boot need not > imply that you encrypt your discs. You need to encrypt only > kernel memory to meet the requirements. > > As STD affects the whole machine it must require root rights. > So I cannot see how you can talk about a session belonging > to a user. Please explain. > The case is for physical access, not the 'user' in OS. > It seems to me that you can in theory encrypt the password > by a key coming from user space, so that you need to know > an additional key to resume the system, but that seems to me > above and beyond what Secure Boot requires. > Understand. Best, Yu > Regards > Oliver >