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=-8.2 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 85D0DC43331 for ; Fri, 6 Sep 2019 13:19:03 +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 58E62206BB for ; Fri, 6 Sep 2019 13:19:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 58E62206BB 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]:56270 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i6E8k-0002ku-Bk for qemu-devel@archiver.kernel.org; Fri, 06 Sep 2019 09:19:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35422) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i6E80-0001vx-MQ for qemu-devel@nongnu.org; Fri, 06 Sep 2019 09:18:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i6E7y-0004Nn-GZ for qemu-devel@nongnu.org; Fri, 06 Sep 2019 09:18:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37750) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i6E7v-0004Aj-60; Fri, 06 Sep 2019 09:18:11 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 458A21DA9; Fri, 6 Sep 2019 13:18:10 +0000 (UTC) Received: from redhat.com (ovpn-112-50.ams2.redhat.com [10.36.112.50]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BE44960C5E; Fri, 6 Sep 2019 13:18:01 +0000 (UTC) Date: Fri, 6 Sep 2019 14:17:58 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Maxim Levitsky Message-ID: <20190906131758.GH5119@redhat.com> References: <20190826135103.22410-1-mlevitsk@redhat.com> <20190826135103.22410-12-mlevitsk@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190826135103.22410-12-mlevitsk@redhat.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.71]); Fri, 06 Sep 2019 13:18:10 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH v2 11/13] qcrypto-luks: refactoring: simplify the math used for keyslot locations 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 , Fam Zheng , qemu-block@nongnu.org, Markus Armbruster , qemu-devel@nongnu.org, Max Reitz , Stefan Hajnoczi Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Aug 26, 2019 at 04:51:01PM +0300, Maxim Levitsky wrote: > Signed-off-by: Maxim Levitsky > --- > crypto/block-luks.c | 64 +++++++++++++++++++++++++++++---------------- > 1 file changed, 41 insertions(+), 23 deletions(-) >=20 > diff --git a/crypto/block-luks.c b/crypto/block-luks.c > index d713125925..6a43d97ce5 100644 > --- a/crypto/block-luks.c > +++ b/crypto/block-luks.c > @@ -409,6 +409,32 @@ qcrypto_block_luks_essiv_cipher(QCryptoCipherAlgor= ithm cipher, > } > } > =20 > +/* > + * Returns number of sectors needed to store the key material > + * given number of anti forensic stripes > + */ > +static int > +qcrypto_block_luks_splitkeylen_sectors(const QCryptoBlockLUKS *luks, > + unsigned int stripes) > +{ > + /* > + * This calculation doesn't match that shown in the spec, > + * but instead follows the cryptsetup implementation. > + */ > + > + size_t header_sectors =3D QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > + QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; The caller already calculated that so just pass it in > + > + size_t splitkeylen =3D luks->header.master_key_len * stripes; > + > + /* First align the key material size to block size*/ > + size_t splitkeylen_sectors =3D > + DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE); > + > + /* Then also align the key material size to the size of the header= */ > + return ROUND_UP(splitkeylen_sectors, header_sectors); > +} > + > /* > * Stores the main LUKS header, taking care of endianess > */ > @@ -1151,7 +1177,8 @@ qcrypto_block_luks_create(QCryptoBlock *block, > QCryptoBlockCreateOptionsLUKS luks_opts; > Error *local_err =3D NULL; > g_autofree uint8_t *masterkey =3D NULL; > - size_t splitkeylen =3D 0; > + size_t header_sectors; > + size_t split_key_sectors; > size_t i; > g_autofree char *password; > const char *cipher_alg; > @@ -1370,37 +1397,28 @@ qcrypto_block_luks_create(QCryptoBlock *block, > goto error; > } > =20 > + /* start with the sector that follows the header*/ > + header_sectors =3D QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > + QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; > + > + split_key_sectors =3D > + qcrypto_block_luks_splitkeylen_sectors(luks, > + QCRYPTO_BLOCK_LUKS_STRI= PES); > =20 > - /* Although LUKS has multiple key slots, we're just going > - * to use the first key slot */ > - splitkeylen =3D luks->header.master_key_len * QCRYPTO_BLOCK_LUKS_S= TRIPES; > for (i =3D 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { > - luks->header.key_slots[i].active =3D QCRYPTO_BLOCK_LUKS_KEY_SL= OT_DISABLED; > - luks->header.key_slots[i].stripes =3D QCRYPTO_BLOCK_LUKS_STRIP= ES; > + QCryptoBlockLUKSKeySlot *slot =3D &luks->header.key_slots[i]; > + slot->active =3D QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; > =20 > - /* This calculation doesn't match that shown in the spec, > - * but instead follows the cryptsetup implementation. > - */ > - luks->header.key_slots[i].key_offset_sector =3D > - (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > - QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + > - (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SEC= TOR_SIZE), > - (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > - QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * i); > + slot->key_offset_sector =3D header_sectors + i * split_key_sec= tors; > + slot->stripes =3D QCRYPTO_BLOCK_LUKS_STRIPES; > } > =20 > - > /* The total size of the LUKS headers is the partition header + ke= y > * slot headers, rounded up to the nearest sector, combined with > * the size of each master key material region, also rounded up > * to the nearest sector */ > - luks->header.payload_offset_sector =3D > - (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > - QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + > - (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_= SIZE), > - (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > - QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * > - QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); > + luks->header.payload_offset_sector =3D header_sectors + > + QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS * split_key_sectors; > =20 > block->sector_size =3D QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; > block->payload_offset =3D luks->header.payload_offset_sector * Reviewed-by: Daniel P. Berrang=C3=A9 Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :|