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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B9B4DC47DB3 for ; Wed, 31 Jan 2024 10:56:06 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rV8Fi-0004rO-Ec; Wed, 31 Jan 2024 05:55:34 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rV8Fd-0004hA-OK for qemu-devel@nongnu.org; Wed, 31 Jan 2024 05:55:30 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rV8FU-000146-7Q for qemu-devel@nongnu.org; Wed, 31 Jan 2024 05:55:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1706698515; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1kT8gFAXjvNkdmg7VFaKQP0MrzdMnCiqgaJz/8f2Qn4=; b=LP0kYBkvQAQJER8rclPtSO61dihDtP/ZMZOgEjcV+1xIaxLZUAF+Mlq+T07f+C+PpIQRDW tcTiRQPbiGFmncZXsS1g/DJTxDi/RHvj7jJk4yYFDwoIGPegKanZy+Hi0/YDAaoRurhQSF xBMmInZX+skvE/1/Adn8I39NWwYx3GA= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-274-wKLE1SMoPZ-DKcIQPTcevg-1; Wed, 31 Jan 2024 05:55:12 -0500 X-MC-Unique: wKLE1SMoPZ-DKcIQPTcevg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C6D1985A589; Wed, 31 Jan 2024 10:55:11 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.72]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2E005C2590D; Wed, 31 Jan 2024 10:55:09 +0000 (UTC) Date: Wed, 31 Jan 2024 10:55:06 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: yong.huang@smartx.com Cc: qemu-devel@nongnu.org, Eric Blake , Markus Armbruster , Hanna Reitz , Kevin Wolf Subject: Re: [PATCH v4 1/7] crypto: Support LUKS volume with detached header Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.12 (2023-09-09) X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -33 X-Spam_score: -3.4 X-Spam_bar: --- X-Spam_report: (-3.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.292, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, Jan 30, 2024 at 01:37:19PM +0800, yong.huang@smartx.com wrote: > From: Hyman Huang > > By enhancing the LUKS driver, it is possible to implement > the LUKS volume with a detached header. > > Normally a LUKS volume has a layout: > disk: | header | key material | disk payload data | > > With a detached LUKS header, you need 2 disks so getting: > disk1: | header | key material | > disk2: | disk payload data | > > There are a variety of benefits to doing this: > * Secrecy - the disk2 cannot be identified as containing LUKS > volume since there's no header > * Control - if access to the disk1 is restricted, then even > if someone has access to disk2 they can't unlock > it. Might be useful if you have disks on NFS but > want to restrict which host can launch a VM > instance from it, by dynamically providing access > to the header to a designated host > * Flexibility - your application data volume may be a given > size and it is inconvenient to resize it to > add encryption.You can store the LUKS header > separately and use the existing storage > volume for payload > * Recovery - corruption of a bit in the header may make the > entire payload inaccessible. It might be > convenient to take backups of the header. If > your primary disk header becomes corrupt, you > can unlock the data still by pointing to the > backup detached header > > Take the raw-format image as an example to introduce the usage > of the LUKS volume with a detached header: > > 1. prepare detached LUKS header images > $ dd if=/dev/zero of=test-header.img bs=1M count=32 > $ dd if=/dev/zero of=test-payload.img bs=1M count=1000 > $ cryptsetup luksFormat --header test-header.img test-payload.img > > --force-password --type luks1 > > 2. block-add a protocol blockdev node of payload image > $ virsh qemu-monitor-command vm '{"execute":"blockdev-add", > > "arguments":{"node-name":"libvirt-1-storage", "driver":"file", > > "filename":"test-payload.img"}}' > > 3. block-add a protocol blockdev node of LUKS header as above. > $ virsh qemu-monitor-command vm '{"execute":"blockdev-add", > > "arguments":{"node-name":"libvirt-2-storage", "driver":"file", > > "filename": "test-header.img" }}' > > 4. object-add the secret for decrypting the cipher stored in > LUKS header above > $ virsh qemu-monitor-command vm '{"execute":"object-add", > > "arguments":{"qom-type":"secret", "id": > > "libvirt-2-storage-secret0", "data":"abc123"}}' > > 5. block-add the raw-drived blockdev format node > $ virsh qemu-monitor-command vm '{"execute":"blockdev-add", > > "arguments":{"node-name":"libvirt-1-format", "driver":"raw", > > "file":"libvirt-1-storage"}}' > > 6. block-add the luks-drived blockdev to link the raw disk > with the LUKS header by specifying the field "header" > $ virsh qemu-monitor-command vm '{"execute":"blockdev-add", > > "arguments":{"node-name":"libvirt-2-format", "driver":"luks", > > "file":"libvirt-1-format", "header":"libvirt-2-storage", > > "key-secret":"libvirt-2-format-secret0"}}' > > 7. hot-plug the virtio-blk device finally > $ virsh qemu-monitor-command vm '{"execute":"device_add", > > "arguments": {"num-queues":"1", "driver":"virtio-blk-pci", > > "drive": "libvirt-2-format", "id":"virtio-disk2"}}' > > Starting a VM with a LUKS volume with detached header is > somewhat similar to hot-plug in that both maintaining the > same json command while the starting VM changes the > "blockdev-add/device_add" parameters to "blockdev/device". > > Signed-off-by: Hyman Huang > --- > block/crypto.c | 21 +++++++++++++++++++-- > crypto/block-luks.c | 11 +++++++---- > include/crypto/block.h | 5 +++++ > qapi/block-core.json | 5 ++++- > 4 files changed, 35 insertions(+), 7 deletions(-) Reviewed-by: Daniel P. Berrangé With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|