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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 77381C352A3 for ; Thu, 6 Feb 2020 15:24:37 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 433DF222C2 for ; Thu, 6 Feb 2020 15:24:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="gAjB/KRZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 433DF222C2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:40930 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1izj1A-0004tZ-GZ for qemu-devel@archiver.kernel.org; Thu, 06 Feb 2020 10:24:36 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:58894) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1izj0O-0004Cu-L6 for qemu-devel@nongnu.org; Thu, 06 Feb 2020 10:23:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1izj0M-0002Wf-EA for qemu-devel@nongnu.org; Thu, 06 Feb 2020 10:23:48 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:21194 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1izj0M-0002V9-9m for qemu-devel@nongnu.org; Thu, 06 Feb 2020 10:23:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1581002625; h=from:from: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=frT20pU/RjQ2r9luRwhPtlE7Pt0yhLVNYzj/kUPxnpk=; b=gAjB/KRZBLbjAEmiSEx5RoFdR6DtIrwG1Vhn/TGwrckH9f2Crs82cQ3Ry2AHhrHdmdkmnr TWCdlH3Q3zwUHvyMUzWaEyq9CV8oc/4O5d/4JkAgwwoHuJxHn8o1mC1Jk/Lru6VLeJ55qr +1t8w9703Bb3aeaTejD7R0nZB1XlIrU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-86-CtVZkGUTPQCrv3U-1qEqbw-1; Thu, 06 Feb 2020 10:23:44 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 776188018AD; Thu, 6 Feb 2020 15:23:43 +0000 (UTC) Received: from maximlenovopc.usersys.redhat.com (unknown [10.35.206.95]) by smtp.corp.redhat.com (Postfix) with ESMTP id 09FF777927; Thu, 6 Feb 2020 15:23:38 +0000 (UTC) Message-ID: <409d70e1a13c6fd94094d99ac32c8201dbdbc1d8.camel@redhat.com> Subject: Re: [PATCH 02/13] qcrypto-luks: implement encryption key management From: Maxim Levitsky To: Markus Armbruster , Kevin Wolf Date: Thu, 06 Feb 2020 17:23:37 +0200 In-Reply-To: <87pnerd9pf.fsf@dusky.pond.sub.org> References: <20200130125319.GD1891831@redhat.com> <87zhe5ovbv.fsf@dusky.pond.sub.org> <20200130150108.GM1891831@redhat.com> <877e18oq76.fsf@dusky.pond.sub.org> <87mu9xxwzv.fsf@dusky.pond.sub.org> <20200205093011.GA5768@dhcp-200-226.str.redhat.com> <20200205102303.GB2221087@redhat.com> <87a75xgl6w.fsf@dusky.pond.sub.org> <87h803ua2c.fsf@dusky.pond.sub.org> <20200206133658.GL2391707@redhat.com> <20200206142558.GB4926@linux.fritz.box> <87pnerd9pf.fsf@dusky.pond.sub.org> Mime-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-MC-Unique: CtVZkGUTPQCrv3U-1qEqbw-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: John Snow , Daniel =?ISO-8859-1?Q?P=2EBerrang=E9?= , qemu-devel@nongnu.org, qemu-block@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, 2020-02-06 at 16:19 +0100, Markus Armbruster wrote: > Kevin Wolf writes: >=20 > > Am 06.02.2020 um 14:36 hat Daniel P. Berrang=C3=A9 geschrieben: > > > On Thu, Feb 06, 2020 at 02:20:11PM +0100, Markus Armbruster wrote: > > > > One more question regarding the array in > > > >=20 > > > > { 'struct': 'QCryptoBlockAmendOptionsLUKS', > > > > 'data' : { > > > > 'keys': ['LUKSKeyslotUpdate'], > > > > '*unlock-secret' : 'str' } } > > > >=20 > > > > Why an array? Do we really need multiple keyslot updates in one am= end > > > > operation? > > >=20 > > > I think it it is unlikely we'd use this in libvirt. In the case of wa= nting > > > to *change* a key, it is safer to do a sequence of "add key" and then > > > "remove key". If you combine them into the same operation, and you ge= t > > > an error back, it is hard to know /where/ it failed ? was the new key > > > added or not ? > >=20 > > I think the array came in because of the "describe the new state" > > approach. The state has eight keyslots, so in order to fully describe > > the new state, you would have to be able to pass multiple slots at once= . >=20 > I see. >=20 > Of course, it can also describe multiple new states for the same slot. >=20 > Example: >=20 > [{'state': 'active', 'keyslot': 0, 'secret': 'sec0'}, > {'state': 'active', 'keyslot': 0, 'secret': 'sec1'}] >=20 > where slot 0's old state is 'inactive'. >=20 > Which one is the new state? >=20 > If we execute the array elements one by one, this first makes slot 0 > active with secret 'sec0', then tries to make it active with secret > 'sec1', which fails. Simple enough, but it's not really "describe the > new state", it's still "specify a series of state transitions". >=20 > If we merge the array elements into a description of the new state of > all eight slots, where a slot's description can be "same as old state", > then this makes slot 0 active with either secret 'sec0' or 'sec1', > depending on how we resolve the conflict. We could even make conflicts > an error, and then this would fail without changing anything. >=20 > What do we want? >=20 > Is this worth the trouble? Yes, that is my thoughts on this as well. Best regards, =09Maxim Levitsky