From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34268) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bi2Ar-00010c-R6 for qemu-devel@nongnu.org; Thu, 08 Sep 2016 12:27:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bi2Ao-00076D-RK for qemu-devel@nongnu.org; Thu, 08 Sep 2016 12:27:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58756) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bi2Ao-000768-LX for qemu-devel@nongnu.org; Thu, 08 Sep 2016 12:27:34 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (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 515DF62657 for ; Thu, 8 Sep 2016 16:27:34 +0000 (UTC) From: "Daniel P. Berrange" Date: Thu, 8 Sep 2016 17:27:23 +0100 Message-Id: <1473352047-908-3-git-send-email-berrange@redhat.com> In-Reply-To: <1473352047-908-1-git-send-email-berrange@redhat.com> References: <1473352047-908-1-git-send-email-berrange@redhat.com> Subject: [Qemu-devel] [PATCH 2/6] 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 | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/crypto/pbkdf.c b/crypto/pbkdf.c index 695cc35..35dccc2 100644 --- a/crypto/pbkdf.c +++ b/crypto/pbkdf.c @@ -67,13 +67,14 @@ int qcrypto_pbkdf2_count_iters(QCryptoHashAlgorithm hash, const uint8_t *salt, size_t nsalt, Error **errp) { + int ret = -1; uint8_t out[32]; long long int 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 @@ int 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; @@ -103,8 +104,12 @@ int qcrypto_pbkdf2_count_iters(QCryptoHashAlgorithm hash, if (iterations > INT32_MAX) { error_setg(errp, "Iterations %lld too large for a 32-bit int", iterations); - return -1; + goto cleanup; } - return iterations; + ret = iterations; + + cleanup: + memset(out, 0, sizeof(out)); + return ret; } -- 2.7.4