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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 06882C11D2F for ; Mon, 24 Feb 2020 14:46:02 +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 C4D4220714 for ; Mon, 24 Feb 2020 14:46:01 +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="SVb5V8rk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C4D4220714 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]:37628 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j6Ezg-0002Hw-VJ for qemu-devel@archiver.kernel.org; Mon, 24 Feb 2020 09:46:00 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52709) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j6ExT-0000Sq-Ax for qemu-devel@nongnu.org; Mon, 24 Feb 2020 09:43:44 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j6ExS-0007Xk-17 for qemu-devel@nongnu.org; Mon, 24 Feb 2020 09:43:43 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:43676 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j6ExR-0007Xe-Sj for qemu-devel@nongnu.org; Mon, 24 Feb 2020 09:43:41 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582555421; 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=ELIRJW++q5+xz3dY5jYArDty86u8tOgUfi/0jnLdeyA=; b=SVb5V8rkv2YmgfLwi6R5LfC/cf+hQ3wI4qWWDnLbpeVECS4EjefY2oOPXzWuZ8/vhFYGDV dfCeHA7fLiuihRU5VA5BE6a049n19jIg7S7Tj2IvH1E2ZM4ow2JIagnCwIgZ/POPNVZMl7 zU+C1kSzAzr3IL+tqwkj90purv51zbE= 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-132-oOQjATuhPt2dG-uvj_xCbg-1; Mon, 24 Feb 2020 09:43:35 -0500 X-MC-Unique: oOQjATuhPt2dG-uvj_xCbg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 552F68017CC; Mon, 24 Feb 2020 14:43:34 +0000 (UTC) Received: from redhat.com (unknown [10.42.16.105]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 20F9919C7F; Mon, 24 Feb 2020 14:43:33 +0000 (UTC) Date: Mon, 24 Feb 2020 14:43:30 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Markus Armbruster Subject: Re: QAPI schema for desired state of LUKS keyslots Message-ID: <20200224144330.GR635661@redhat.com> References: <20200114193350.10830-1-mlevitsk@redhat.com> <20200114193350.10830-3-mlevitsk@redhat.com> <87lfp36gzh.fsf_-_@dusky.pond.sub.org> <20200217103700.GC6309@linux.fritz.box> <87ftf9s8ho.fsf@dusky.pond.sub.org> MIME-Version: 1.0 In-Reply-To: <87ftf9s8ho.fsf@dusky.pond.sub.org> User-Agent: Mutt/1.13.3 (2020-01-12) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.61 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Kevin Wolf , qemu-block@nongnu.org, qemu-devel@nongnu.org, Maxim Levitsky , Max Reitz , John Snow Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Feb 17, 2020 at 01:28:51PM +0100, Markus Armbruster wrote: > Kevin Wolf writes: >=20 > > Am 15.02.2020 um 15:51 hat Markus Armbruster geschrieben: > >> Review of this patch led to a lengthy QAPI schema design discussion. > >> Let me try to condense it into a concrete proposal. > >>=20 > >> This is about the QAPI schema, and therefore about QMP. The > >> human-friendly interface is out of scope. Not because it's not > >> important (it clearly is!), only because we need to *focus* to have a > >> chance at success. > >>=20 > >> I'm going to include a few design options. I'll mark them "Option:". > >>=20 > >> The proposed "amend" interface takes a specification of desired state, > >> and figures out how to get from here to there by itself. LUKS keyslot= s > >> are one part of desired state. > >>=20 > >> We commonly have eight LUKS keyslots. Each keyslot is either active o= r > >> inactive. An active keyslot holds a secret. > >>=20 > >> Goal: a QAPI type for specifying desired state of LUKS keyslots. > >>=20 > >> Proposal: > >>=20 > >> { 'enum': 'LUKSKeyslotState', > >> 'data': [ 'active', 'inactive' ] } > >>=20 > >> { 'struct': 'LUKSKeyslotActive', > >> 'data': { 'secret': 'str', > >> '*iter-time': 'int } } > >>=20 > >> { 'struct': 'LUKSKeyslotInactive', > >> 'data': { '*old-secret': 'str' } } > >>=20 > >> { 'union': 'LUKSKeyslotAmend', > >> 'base': { '*keyslot': 'int', > >> 'state': 'LUKSKeyslotState' } > >> 'discriminator': 'state', > >> 'data': { 'active': 'LUKSKeyslotActive', > >> 'inactive': 'LUKSKeyslotInactive' } } > >>=20 > >> LUKSKeyslotAmend specifies desired state for a set of keyslots. > > > > Though not arbitrary sets of keyslots, it's only a single keyslot or > > multiple keyslots containing the same secret. Might be good enough in > > practice, though it means that you may have to issue multiple amend > > commands to get to the final state that you really want (even if doing > > everything at once would be safe). >=20 > True. I traded expressiveness for simplicity. >=20 > Here's the only practical case I can think of where the lack of > expressiveness may hurt: replace secrets. >=20 > With this interface, you need two operations: activate a free slot with > the new secret, deactivate the slot(s) with the old secret. There is an > intermediate state with both secrets active. >=20 > A more expressive interface could let you do both in one step. Relevant > only if the implementation actually provides atomicity. Can it? This restriction is already present in the the long standing cryptsetup command, so I don't think it is a big deal. Or to put it another way I don't see a compelling justification for why QEMU needs to be special and do it in op. Regards, Daniel --=20 |: 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= :|