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,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 AE2BCC3A59D for ; Thu, 22 Aug 2019 10:49:03 +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 7875B206B7 for ; Thu, 22 Aug 2019 10:49:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7875B206B7 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]:40470 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i0keM-0003MD-I9 for qemu-devel@archiver.kernel.org; Thu, 22 Aug 2019 06:49:02 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42314) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i0kce-0002kB-Ny for qemu-devel@nongnu.org; Thu, 22 Aug 2019 06:47:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i0kcd-00072g-9D for qemu-devel@nongnu.org; Thu, 22 Aug 2019 06:47:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58340) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i0kcZ-0006y3-SK; Thu, 22 Aug 2019 06:47:12 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id DCD5530014B7; Thu, 22 Aug 2019 10:47:10 +0000 (UTC) Received: from redhat.com (unknown [10.42.16.132]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 088BB5D9E5; Thu, 22 Aug 2019 10:47:06 +0000 (UTC) Date: Thu, 22 Aug 2019 11:47:04 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Maxim Levitsky Message-ID: <20190822104704.GI3267@redhat.com> References: <20190814202219.1870-1-mlevitsk@redhat.com> <20190814202219.1870-5-mlevitsk@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190814202219.1870-5-mlevitsk@redhat.com> User-Agent: Mutt/1.12.0 (2019-05-25) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Thu, 22 Aug 2019 10:47:10 +0000 (UTC) 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: , 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 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(-) > > 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) > } > > > +/* > + * Returns number of sectors needed to store the key material > + * given number of anti forensic stripes > + */ > +static int splitkeylen_sectors(QCryptoBlockLUKS *luks, int stripes) Needs a qcrypto_block_luks_ prefix on method name. I'd also put 'static int' on a separate line from method name to reduce too long lines. > + > +{ > + /* > + * This calculation doesn't match that shown in the spec, > + * but instead follows the cryptsetup implementation. > + */ > + > + size_t header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > + QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; Following line indent should only be 4 spaces > + > + size_t splitkeylen = masterkeylen(luks) * stripes; > + > + /* First align the key material size to block size*/ > + size_t splitkeylen_sectors = > + DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE); Again 4 space indent. > + > + /* 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 > */ > @@ -1169,7 +1196,7 @@ qcrypto_block_luks_create(QCryptoBlock *block, > QCryptoBlockCreateOptionsLUKS luks_opts; > Error *local_err = NULL; > uint8_t *masterkey = NULL; > - size_t splitkeylen = 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; > } > > + /* start with the sector that follows the header*/ > + next_sector = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / > + QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; I'd suggest 'post_header_sector' > > - /* Although LUKS has multiple key slots, we're just going > - * to use the first key slot */ > - splitkeylen = luks->header.key_bytes * QCRYPTO_BLOCK_LUKS_STRIPES; > for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { > - luks->header.key_slots[i].active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; > - luks->header.key_slots[i].stripes = QCRYPTO_BLOCK_LUKS_STRIPES; > - > - /* This calculation doesn't match that shown in the spec, > - * but instead follows the cryptsetup implementation. > - */ > - luks->header.key_slots[i].key_offset = > - (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)) * i); > + QCryptoBlockLUKSKeySlot *slot = &luks->header.key_slots[i]; > + slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; > + slot->key_offset = next_sector; > + slot->stripes = QCRYPTO_BLOCK_LUKS_STRIPES; > + next_sector += splitkeylen_sectors(luks, QCRYPTO_BLOCK_LUKS_STRIPES); I'm not a fan of the next_sector accumulator . I'd prefer to see the '* i' part done in splitkeylen_sectors, so that we have slot->key_offset = post_header_sector + splitkeylen_sectors(luks, QCRYPTO_BLOCK_LUKS_STRIPES, i); > @@ -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 = > - (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 = next_sector; luks->header.payload_offset = post_header_sector + splitkeylen_sectors(luks, QCRYPTO_BLOCK_LUKS_STRIPES, QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); > block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; > - block->payload_offset = luks->header.payload_offset * > - block->sector_size; > + block->payload_offset = luks->header.payload_offset * block->sector_size; This is reverting a whitspace change done in previous method 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 :|