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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 9728AC07E95 for ; Wed, 7 Jul 2021 13:49:35 +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 F158060BD3 for ; Wed, 7 Jul 2021 13:49:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F158060BD3 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]:41006 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m17vh-0005EH-RQ for qemu-devel@archiver.kernel.org; Wed, 07 Jul 2021 09:49:33 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46080) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m17uz-0004Z2-T2 for qemu-devel@nongnu.org; Wed, 07 Jul 2021 09:48:49 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:36055) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m17ux-0006b4-OS for qemu-devel@nongnu.org; Wed, 07 Jul 2021 09:48:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1625665726; 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=zFpWkfg36IapJrt8ZcF7l+LiUnUY7WO1wMsSRjKfx2E=; b=R3sU9nmrA+sTuepsagFh00qddGG8CPCFIqDpZzSuiitZh/sMErzUdOdD32MIHMWmJ/xtNS 0HXWth8DoUFuVSzFvNbKKYZkpWPVTxqH34kmUA9yWn79DW1F4HR70rezYu+RE74Rs2Q+vr dfdfLh3p4kkvrdEa2Q4Zn6j1ScavMBI= 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-504-oWwkz5ZpM-aO851S9RhXyQ-1; Wed, 07 Jul 2021 09:48:45 -0400 X-MC-Unique: oWwkz5ZpM-aO851S9RhXyQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A91198042DE for ; Wed, 7 Jul 2021 13:48:44 +0000 (UTC) Received: from redhat.com (ovpn-113-81.ams2.redhat.com [10.36.113.81]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A040F5D9D3; Wed, 7 Jul 2021 13:48:39 +0000 (UTC) Date: Wed, 7 Jul 2021 14:48:37 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Markus Armbruster Subject: Re: [PATCH 11/18] crypto: rename des-rfb cipher to just des Message-ID: References: <20210706095924.764117-1-berrange@redhat.com> <20210706095924.764117-12-berrange@redhat.com> <87eecaffzg.fsf@dusky.pond.sub.org> MIME-Version: 1.0 In-Reply-To: <87eecaffzg.fsf@dusky.pond.sub.org> User-Agent: Mutt/2.0.7 (2021-05-04) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit 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: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.439, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: Eric Blake , qemu-devel@nongnu.org, Gerd Hoffmann Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Jul 07, 2021 at 02:47:15PM +0200, Markus Armbruster wrote: > Daniel P. Berrangé writes: > > > Currently the crypto layer exposes support for a 'des-rfb' > > algorithm which is just normal single-DES, with the bits > > in each key byte reversed. This special key munging is > > required by the RFB protocol password authentication > > mechanism. > > > > Since the crypto layer is generic shared code, it makes > > more sense to do the key byte munging in the VNC server > > code, and expose normal single-DES support. > > > > Signed-off-by: Daniel P. Berrangé > > --- > > [...] > > > diff --git a/qapi/crypto.json b/qapi/crypto.json > > index 7116ae9a46..6b3fadabac 100644 > > --- a/qapi/crypto.json > > +++ b/qapi/crypto.json > > @@ -66,7 +66,7 @@ > > # @aes-128: AES with 128 bit / 16 byte keys > > # @aes-192: AES with 192 bit / 24 byte keys > > # @aes-256: AES with 256 bit / 32 byte keys > > -# @des-rfb: RFB specific variant of single DES. Do not use except in VNC. > > +# @des: DES with 56 bit / 8 byte keys. Do not use except in VNC. > > # @3des: 3DES(EDE) with 192 bit / 24 byte keys (since 2.9) > > # @cast5-128: Cast5 with 128 bit / 16 byte keys > > # @serpent-128: Serpent with 128 bit / 16 byte keys > > @@ -80,7 +80,7 @@ > > { 'enum': 'QCryptoCipherAlgorithm', > > 'prefix': 'QCRYPTO_CIPHER_ALG', > > 'data': ['aes-128', 'aes-192', 'aes-256', > > - 'des-rfb', '3des', > > + 'des', '3des', > > 'cast5-128', > > 'serpent-128', 'serpent-192', 'serpent-256', > > 'twofish-128', 'twofish-192', 'twofish-256']} > > Is enum value "des-rfb" part of any external interface? Strictly speaking, yes, but in reality it doesn't matter. The only place in QEMU that actually uses DES-RFB is the VNC server code. That is an indirect usage when the user sets the "password" option flag in QemuOpts. The fact that it uses DES-RFB is an internal impl detail. The one place that does publically expose ability to set a field using the QCryptoCipherAlgorithm enum type is the LUKS support in the block layer: { 'struct': 'QCryptoBlockCreateOptionsLUKS', 'base': 'QCryptoBlockOptionsLUKS', 'data': { '*cipher-alg': 'QCryptoCipherAlgorithm', '*cipher-mode': 'QCryptoCipherMode', '*ivgen-alg': 'QCryptoIVGenAlgorithm', '*ivgen-hash-alg': 'QCryptoHashAlgorithm', '*hash-alg': 'QCryptoHashAlgorithm', '*iter-time': 'int'}} eg exposed on CLI as: $ qemu-img create -f luks -o cipher-alg=NNN foo.luks 1G or equivalant with QMP blockdev-create While the QMP schema allows any valid QCryptoCipherAlgorithm string to be set, the actual implementation does not. The crypto/block-luks.c code has a map between cipher algs and LUKS format algoritm names: static const QCryptoBlockLUKSCipherNameMap qcrypto_block_luks_cipher_name_map[] = { { "aes", qcrypto_block_luks_cipher_size_map_aes }, { "cast5", qcrypto_block_luks_cipher_size_map_cast5 }, { "serpent", qcrypto_block_luks_cipher_size_map_serpent }, { "twofish", qcrypto_block_luks_cipher_size_map_twofish }, }; If it isn't in that table, it can't be used. IOW, the only scenario we're affecting in this rename is one which would already result in an error condition Original behaviour: $ qemu-img create -f luks --object secret,id=sec0,data=123 -o cipher-alg=des-rfb,key-secret=sec0 demo.luks 1G Formatting 'demo.luks', fmt=luks size=1073741824 key-secret=sec0 cipher-alg=des-rfb qemu-img: demo.luks: Algorithm 'des-rfb' not supported New behaviour: $ qemu-img create -f luks --object secret,id=sec0,data=123 -o cipher-alg=des-rfb,key-secret=sec0 demo.luks 1G Formatting 'demo.luks', fmt=luks size=1073741824 key-secret=sec0 cipher-alg=des-fish qemu-img: demo.luks: Invalid parameter 'des-rfb' I considered this incompatibility to be acceptable, and thus not worth going through a deprecation dance. 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 :|