From patchwork Mon Sep 12 14:13:39 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= X-Patchwork-Id: 668820 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3sXrPJ6Sb1z9sC4 for ; Tue, 13 Sep 2016 00:52:04 +1000 (AEST) Received: from localhost ([::1]:43348 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bjSaY-0001lT-Jj for incoming@patchwork.ozlabs.org; Mon, 12 Sep 2016 10:52:02 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53725) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bjRze-0005UY-L4 for qemu-devel@nongnu.org; Mon, 12 Sep 2016 10:13:59 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bjRzc-0005Ql-4O for qemu-devel@nongnu.org; Mon, 12 Sep 2016 10:13:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45532) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bjRzb-0005Qd-VT for qemu-devel@nongnu.org; Mon, 12 Sep 2016 10:13:52 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 9E8224E4EF for ; Mon, 12 Sep 2016 14:13:51 +0000 (UTC) Received: from t530wlan.home.berrange.com.com (vpn1-5-27.ams2.redhat.com [10.36.5.27]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u8CEDkpM018321; Mon, 12 Sep 2016 10:13:50 -0400 From: "Daniel P. Berrange" To: qemu-devel@nongnu.org Date: Mon, 12 Sep 2016 15:13:39 +0100 Message-Id: <1473689623-28870-4-git-send-email-berrange@redhat.com> In-Reply-To: <1473689623-28870-1-git-send-email-berrange@redhat.com> References: <1473689623-28870-1-git-send-email-berrange@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Mon, 12 Sep 2016 14:13:51 +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 3/7] crypto: clear out buffer after timing pbkdf algorithm X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" The 'out' buffer will hold a key derived from master password, so it is best practice to clear this buffer when no longer required. Signed-off-by: Daniel P. Berrange Reviewed-by: Eric Blake --- crypto/pbkdf.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/crypto/pbkdf.c b/crypto/pbkdf.c index 929458b..e391505 100644 --- a/crypto/pbkdf.c +++ b/crypto/pbkdf.c @@ -67,13 +67,14 @@ uint64_t qcrypto_pbkdf2_count_iters(QCryptoHashAlgorithm hash, const uint8_t *salt, size_t nsalt, Error **errp) { + uint64_t ret = -1; uint8_t out[32]; uint64_t iterations = (1 << 15); unsigned long long delta_ms, start_ms, end_ms; while (1) { if (qcrypto_pbkdf2_get_thread_cpu(&start_ms, errp) < 0) { - return -1; + goto cleanup; } if (qcrypto_pbkdf2(hash, key, nkey, @@ -81,10 +82,10 @@ uint64_t qcrypto_pbkdf2_count_iters(QCryptoHashAlgorithm hash, iterations, out, sizeof(out), errp) < 0) { - return -1; + goto cleanup; } if (qcrypto_pbkdf2_get_thread_cpu(&end_ms, errp) < 0) { - return -1; + goto cleanup; } delta_ms = end_ms - start_ms; @@ -100,5 +101,9 @@ uint64_t qcrypto_pbkdf2_count_iters(QCryptoHashAlgorithm hash, iterations = iterations * 1000 / delta_ms; - return iterations; + ret = iterations; + + cleanup: + memset(out, 0, sizeof(out)); + return ret; }