From patchwork Mon Aug 26 13:51:01 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Maxim Levitsky X-Patchwork-Id: 1153203 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 ozlabs.org (Postfix) with ESMTPS id 46HD9w488Rz9s7T for ; Mon, 26 Aug 2019 23:58:28 +1000 (AEST) Received: from localhost ([::1]:53136 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i2FVq-00052z-4q for incoming@patchwork.ozlabs.org; Mon, 26 Aug 2019 09:58:26 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:38361) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i2FQ4-0000G0-Oy for qemu-devel@nongnu.org; Mon, 26 Aug 2019 09:52:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i2FQ3-0007MI-EF for qemu-devel@nongnu.org; Mon, 26 Aug 2019 09:52:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49528) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i2FQ0-0007J6-Po; Mon, 26 Aug 2019 09:52:24 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 29588796E6; Mon, 26 Aug 2019 13:52:24 +0000 (UTC) Received: from maximlenovopc.usersys.redhat.com (unknown [10.35.206.67]) by smtp.corp.redhat.com (Postfix) with ESMTP id B1B8B5D704; Mon, 26 Aug 2019 13:52:21 +0000 (UTC) From: Maxim Levitsky To: qemu-devel@nongnu.org Date: Mon, 26 Aug 2019 16:51:01 +0300 Message-Id: <20190826135103.22410-12-mlevitsk@redhat.com> In-Reply-To: <20190826135103.22410-1-mlevitsk@redhat.com> References: <20190826135103.22410-1-mlevitsk@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Mon, 26 Aug 2019 13:52:24 +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: [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: , Cc: Kevin Wolf , Fam Zheng , =?utf-8?q?D?= =?utf-8?q?aniel_P=2E_Berrang=C3=A9?= , qemu-block@nongnu.org, Markus Armbruster , Max Reitz , Stefan Hajnoczi , Maxim Levitsky Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Signed-off-by: Maxim Levitsky Reviewed-by: Daniel P. Berrangé --- crypto/block-luks.c | 64 +++++++++++++++++++++++++++++---------------- 1 file changed, 41 insertions(+), 23 deletions(-) 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(QCryptoCipherAlgorithm cipher, } } +/* + * 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 = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / + QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; + + size_t splitkeylen = luks->header.master_key_len * stripes; + + /* First align the key material size to block size*/ + size_t splitkeylen_sectors = + 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 = NULL; g_autofree uint8_t *masterkey = NULL; - size_t splitkeylen = 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; } + /* start with the sector that follows the header*/ + header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / + QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; + + split_key_sectors = + qcrypto_block_luks_splitkeylen_sectors(luks, + QCRYPTO_BLOCK_LUKS_STRIPES); - /* Although LUKS has multiple key slots, we're just going - * to use the first key slot */ - splitkeylen = luks->header.master_key_len * 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; + QCryptoBlockLUKSKeySlot *slot = &luks->header.key_slots[i]; + slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; - /* This calculation doesn't match that shown in the spec, - * but instead follows the cryptsetup implementation. - */ - luks->header.key_slots[i].key_offset_sector = - (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); + slot->key_offset_sector = header_sectors + i * split_key_sectors; + slot->stripes = QCRYPTO_BLOCK_LUKS_STRIPES; } - /* The total size of the LUKS headers is the partition header + key * 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 = - (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 = header_sectors + + QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS * split_key_sectors; block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; block->payload_offset = luks->header.payload_offset_sector *