From mboxrd@z Thu Jan 1 00:00:00 1970 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) From: "Daniel P. Berrange" 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> Subject: [Qemu-devel] [PATCH v2 3/7] crypto: clear out buffer after timing pbkdf algorithm List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org 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 --- 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; } -- 2.7.4