From patchwork Sun Mar 1 19:40:17 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephan Mueller X-Patchwork-Id: 5909201 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: X-Original-To: patchwork-linux-crypto@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id F0BEDBF6C3 for ; Sun, 1 Mar 2015 19:40:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 0D3FA2026D for ; Sun, 1 Mar 2015 19:40:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 001712028D for ; Sun, 1 Mar 2015 19:40:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752282AbbCATkf (ORCPT ); Sun, 1 Mar 2015 14:40:35 -0500 Received: from mail.eperm.de ([89.247.134.16]:36245 "EHLO mail.eperm.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751141AbbCATkd (ORCPT ); Sun, 1 Mar 2015 14:40:33 -0500 Received: from tachyon.chronox.de (mail.eperm.de [89.247.134.16]) by mail.eperm.de (Postfix) with ESMTPSA id 258862A005C; Sun, 1 Mar 2015 20:40:28 +0100 (CET) From: Stephan Mueller To: 'Herbert Xu Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/2] crypto: drbg: remove superflowous memsets Date: Sun, 01 Mar 2015 20:40:17 +0100 Message-ID: <1676054.DkmtgsCnh5@tachyon.chronox.de> User-Agent: KMail/4.14.4 (Linux/3.18.7-200.fc21.x86_64; KDE/4.14.4; x86_64; ; ) In-Reply-To: <50904620.OAA2OAojed@tachyon.chronox.de> References: <50904620.OAA2OAojed@tachyon.chronox.de> MIME-Version: 1.0 Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The DRBG code contains memset(0) calls to initialize a varaible that are not necessary as the variable is always overwritten by the processing. This patch increases the CTR and Hash DRBGs by about 5%. Signed-off-by: Stephan Mueller --- crypto/drbg.c | 18 ------------------ 1 file changed, 18 deletions(-) diff --git a/crypto/drbg.c b/crypto/drbg.c index c14274a..56c1d7e 100644 --- a/crypto/drbg.c +++ b/crypto/drbg.c @@ -308,9 +308,6 @@ static int drbg_ctr_bcc(struct drbg_state *drbg, drbg_string_fill(&data, out, drbg_blocklen(drbg)); - /* 10.4.3 step 1 */ - memset(out, 0, drbg_blocklen(drbg)); - /* 10.4.3 step 2 / 4 */ list_for_each_entry(curr, in, list) { const unsigned char *pos = curr->buf; @@ -406,7 +403,6 @@ static int drbg_ctr_df(struct drbg_state *drbg, memset(pad, 0, drbg_blocklen(drbg)); memset(iv, 0, drbg_blocklen(drbg)); - memset(temp, 0, drbg_statelen(drbg)); /* 10.4.2 step 1 is implicit as we work byte-wise */ @@ -523,7 +519,6 @@ static int drbg_ctr_update(struct drbg_state *drbg, struct list_head *seed, unsigned int len = 0; struct drbg_string cipherin; - memset(temp, 0, drbg_statelen(drbg) + drbg_blocklen(drbg)); if (3 > reseed) memset(df_data, 0, drbg_statelen(drbg)); @@ -585,8 +580,6 @@ static int drbg_ctr_generate(struct drbg_state *drbg, int ret = 0; struct drbg_string data; - memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); - /* 10.2.1.5.2 step 2 */ if (addtl && !list_empty(addtl)) { ret = drbg_ctr_update(drbg, addtl, 2); @@ -761,7 +754,6 @@ static struct drbg_state_ops drbg_hmac_ops = { .generate = drbg_hmac_generate, .crypto_init = drbg_init_hash_kernel, .crypto_fini = drbg_fini_hash_kernel, - }; #endif /* CONFIG_CRYPTO_DRBG_HMAC */ @@ -838,8 +830,6 @@ static int drbg_hash_df(struct drbg_state *drbg, unsigned char *tmp = drbg->scratchpad + drbg_statelen(drbg); struct drbg_string data; - memset(tmp, 0, drbg_blocklen(drbg)); - /* 10.4.1 step 3 */ input[0] = 1; drbg_cpu_to_be32((outlen * 8), &input[1]); @@ -879,7 +869,6 @@ static int drbg_hash_update(struct drbg_state *drbg, struct list_head *seed, unsigned char *V = drbg->scratchpad; unsigned char prefix = DRBG_PREFIX1; - memset(drbg->scratchpad, 0, drbg_statelen(drbg)); if (!seed) return -EINVAL; @@ -921,9 +910,6 @@ static int drbg_hash_process_addtl(struct drbg_state *drbg, LIST_HEAD(datalist); unsigned char prefix = DRBG_PREFIX2; - /* this is value w as per documentation */ - memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); - /* 10.1.1.4 step 2 */ if (!addtl || list_empty(addtl)) return 0; @@ -959,9 +945,6 @@ static int drbg_hash_hashgen(struct drbg_state *drbg, struct drbg_string data; LIST_HEAD(datalist); - memset(src, 0, drbg_statelen(drbg)); - memset(dst, 0, drbg_blocklen(drbg)); - /* 10.1.1.4 step hashgen 2 */ memcpy(src, drbg->V, drbg_statelen(drbg)); @@ -1018,7 +1001,6 @@ static int drbg_hash_generate(struct drbg_state *drbg, len = drbg_hash_hashgen(drbg, buf, buflen); /* this is the value H as documented in 10.1.1.4 */ - memset(drbg->scratchpad, 0, drbg_blocklen(drbg)); /* 10.1.1.4 step 4 */ drbg_string_fill(&data1, &prefix, 1); list_add_tail(&data1.list, &datalist);