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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 1462CC3A5A1 for ; Sun, 25 Aug 2019 14:32:08 +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 DFBB32080C for ; Sun, 25 Aug 2019 14:32:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DFBB32080C 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]:42882 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i1tYt-0007Ju-12 for qemu-devel@archiver.kernel.org; Sun, 25 Aug 2019 10:32:07 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47280) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i1tXN-0006qx-Lf for qemu-devel@nongnu.org; Sun, 25 Aug 2019 10:30:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i1tXL-0008CX-8W for qemu-devel@nongnu.org; Sun, 25 Aug 2019 10:30:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53386) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i1tXH-0007vL-BN; Sun, 25 Aug 2019 10:30:27 -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 1B364387B1; Sun, 25 Aug 2019 14:30:26 +0000 (UTC) Received: from maximlenovopc.usersys.redhat.com (unknown [10.35.206.49]) by smtp.corp.redhat.com (Postfix) with ESMTP id 42DA360BEC; Sun, 25 Aug 2019 14:30:21 +0000 (UTC) Message-ID: <7cf4bde6ca7bb74adf1dfc40e2d1ad61b83c6b28.camel@redhat.com> From: Maxim Levitsky To: "Daniel P." =?ISO-8859-1?Q?Berrang=E9?= Date: Sun, 25 Aug 2019 17:30:20 +0300 In-Reply-To: <20190822104704.GI3267@redhat.com> References: <20190814202219.1870-1-mlevitsk@redhat.com> <20190814202219.1870-5-mlevitsk@redhat.com> <20190822104704.GI3267@redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 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]); Sun, 25 Aug 2019 14:30:26 +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 04/13] 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: , 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 Thu, 2019-08-22 at 11:47 +0100, Daniel P. Berrang=C3=A9 wrote: > On Wed, Aug 14, 2019 at 11:22:10PM +0300, Maxim Levitsky wrote: > > Signed-off-by: Maxim Levitsky > > --- > > crypto/block-luks.c | 64 +++++++++++++++++++++++++++----------------= -- > > 1 file changed, 38 insertions(+), 26 deletions(-) > >=20 > > diff --git a/crypto/block-luks.c b/crypto/block-luks.c > > index 6bb369f3b4..e1a4df94b7 100644 > > --- a/crypto/block-luks.c > > +++ b/crypto/block-luks.c > > @@ -417,6 +417,33 @@ static int masterkeylen(QCryptoBlockLUKS *luks) > > } > > =20 > > =20 > > +/* > > + * Returns number of sectors needed to store the key material > > + * given number of anti forensic stripes > > + */ > > +static int splitkeylen_sectors(QCryptoBlockLUKS *luks, int stripes) >=20 > Needs a qcrypto_block_luks_ prefix on method name. Done. >=20 > I'd also put 'static int' on a separate line from method name > to reduce too long lines. Done. >=20 > > + > > +{ > > + /* > > + * 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; >=20 > Following line indent should only be 4 spaces I didn't knew that. Fixed. >=20 > > + > > + size_t splitkeylen =3D masterkeylen(luks) * stripes; > > + > > + /* First align the key material size to block size*/ > > + size_t splitkeylen_sectors =3D > > + DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE= ); >=20 > Again 4 space indent. >=20 > > + > > + /* Then also align the key material size to the size of the head= er */ > > + return ROUND_UP(splitkeylen_sectors, header_sectors); > > +} > > + > > + > > + > > /* > > * Stores the main LUKS header, taking care of endianess > > */ > > @@ -1169,7 +1196,7 @@ qcrypto_block_luks_create(QCryptoBlock *block, > > QCryptoBlockCreateOptionsLUKS luks_opts; > > Error *local_err =3D NULL; > > uint8_t *masterkey =3D NULL; > > - size_t splitkeylen =3D 0; > > + size_t next_sector; > > size_t i; > > char *password; > > const char *cipher_alg; > > @@ -1388,23 +1415,16 @@ qcrypto_block_luks_create(QCryptoBlock *block= , > > goto error; > > } > > =20 > > + /* start with the sector that follows the header*/ > > + next_sector =3D QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > > + QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; >=20 > I'd suggest 'post_header_sector' I called it now header_sectors, and each split key, split_key_sectors. I hope that this is good enough. >=20 > > =20 > > - /* Although LUKS has multiple key slots, we're just going > > - * to use the first key slot */ > > - splitkeylen =3D luks->header.key_bytes * QCRYPTO_BLOCK_LUKS_STRI= PES; > > for (i =3D 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { > > - luks->header.key_slots[i].active =3D QCRYPTO_BLOCK_LUKS_KEY_= SLOT_DISABLED; > > - luks->header.key_slots[i].stripes =3D QCRYPTO_BLOCK_LUKS_STR= IPES; > > - > > - /* This calculation doesn't match that shown in the spec, > > - * but instead follows the cryptsetup implementation. > > - */ > > - luks->header.key_slots[i].key_offset =3D > > - (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > > - QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + > > - (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_S= ECTOR_SIZE), > > - (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > > - QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * i); > > + QCryptoBlockLUKSKeySlot *slot =3D &luks->header.key_slots[i]= ; > > + slot->active =3D QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; > > + slot->key_offset =3D next_sector; > > + slot->stripes =3D QCRYPTO_BLOCK_LUKS_STRIPES; > > + next_sector +=3D splitkeylen_sectors(luks, QCRYPTO_BLOCK_LUK= S_STRIPES); >=20 > I'm not a fan of the next_sector accumulator . I actually think that accumulator is cleaner here, but I won't argue about this. Fixed. >=20 > I'd prefer to see the '* i' part done in splitkeylen_sectors, so that > we have >=20 > slot->key_offset =3D post_header_sector + > splitkeylen_sectors(luks, QCRYPTO_BLOCK_LUKS_STRIPES, i); >=20 > > @@ -1412,17 +1432,9 @@ qcrypto_block_luks_create(QCryptoBlock *block, > > * 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 =3D > > - (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > > - QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + > > - (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTO= R_SIZE), > > - (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > > - QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * > > - QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); > > - > > + luks->header.payload_offset =3D next_sector; >=20 > luks->header.payload_offset =3D post_header_sector + > splitkeylen_sectors(luks, QCRYPTO_BLOCK_LUKS_STRIPES, > QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); >=20 >=20 > > block->sector_size =3D QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; > > - block->payload_offset =3D luks->header.payload_offset * > > - block->sector_size; > > + block->payload_offset =3D luks->header.payload_offset * block->s= ector_size; >=20 >=20 > This is reverting a whitspace change done in previous method True. Fixed. >=20 > Regards, > Daniel Best regards, Maxim Levitsky