From patchwork Sun Mar 29 01:07:56 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "M. Vefa Bicakci" X-Patchwork-Id: 6114761 X-Patchwork-Delegate: kvalo@adurom.com Return-Path: X-Original-To: patchwork-linux-wireless@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 F0395BF4A6 for ; Sun, 29 Mar 2015 01:11:29 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id F3342202FF for ; Sun, 29 Mar 2015 01:11:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F19B920218 for ; Sun, 29 Mar 2015 01:11:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752425AbbC2BLO (ORCPT ); Sat, 28 Mar 2015 21:11:14 -0400 Received: from aibo.runbox.com ([91.220.196.211]:60943 "EHLO aibo.runbox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752846AbbC2BIj (ORCPT ); Sat, 28 Mar 2015 21:08:39 -0400 Received: from [10.9.9.206] (helo=mailfront02.runbox.com) by bars.runbox.com with esmtp (Exim 4.71) (envelope-from ) id 1Yc1iP-0007lR-Fu; Sun, 29 Mar 2015 03:08:37 +0200 Received: from cpe5cd9985fdb46-cm602ad088a62b.cpe.net.cable.rogers.com ([99.241.131.156] helo=localhost.localdomain) by mailfront02.runbox.com with esmtpsa (uid:769847 ) (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) id 1Yc1iF-0007Lp-CZ; Sun, 29 Mar 2015 03:08:27 +0200 From: "M. Vefa Bicakci" To: linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org Cc: joe@perches.com, gregkh@linuxfoundation.org, Jes.Sorensen@redhat.com, Larry.Finger@lwfinger.net, mail@beyermatthias.de, m.v.b@runbox.com Subject: [PATCH v5 13/15] staging: rtl8723au: Rework two byte array comparisons Date: Sat, 28 Mar 2015 21:07:56 -0400 Message-Id: <1427591278-982-14-git-send-email-m.v.b@runbox.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1427591278-982-1-git-send-email-m.v.b@runbox.com> References: <1427591278-982-1-git-send-email-m.v.b@runbox.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable 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 Prior to this commit, rtl8723au's rtw_security.c had two instances of byte array comparisons (for CRC checks) where the individual elements of the byte arrays were compared one by one and an error trace would be output if the byte arrays were determined to be different. This commit improves the readability of the CRC verification by placing the individual 4 bytes of each byte array into an 32-bit unsigned integer and comparing the two resulting integers. Thanks to Larry Finger for spotting the code style issues in the previous version of this commit, and thanks to Joe Perches for suggesting the use of 32-bit integer comparisons instead of byte array comparisons. Signed-off-by: M. Vefa Bicakci --- v2: Correct code style issues and compare 32-bit integers instead of byte arrays. Update the commit message to better reflect the nature of the changes. --- drivers/staging/rtl8723au/core/rtw_security.c | 34 +++++++++++---------------- 1 file changed, 14 insertions(+), 20 deletions(-) diff --git a/drivers/staging/rtl8723au/core/rtw_security.c b/drivers/staging/rtl8723au/core/rtw_security.c index bcb5ea68acbe..0ed048fcb36f 100644 --- a/drivers/staging/rtl8723au/core/rtw_security.c +++ b/drivers/staging/rtl8723au/core/rtw_security.c @@ -210,7 +210,7 @@ void rtw_wep_decrypt23a(struct rtw_adapter *padapter, struct recv_frame *precvframe) { /* exclude ICV */ - u8 crc[4]; + u32 actual_crc, expected_crc; struct arc4context mycontext; int length; u32 keylength; @@ -243,16 +243,14 @@ void rtw_wep_decrypt23a(struct rtw_adapter *padapter, arcfour_encrypt(&mycontext, payload, payload, length); /* calculate icv and compare the icv */ - *((u32 *)crc) = le32_to_cpu(getcrc32(payload, length - 4)); + actual_crc = le32_to_cpu(getcrc32(payload, length - 4)); + expected_crc = le32_to_cpu(get_unaligned_le32(&payload[length - 4])); - if (crc[3] != payload[length - 1] || crc[2] != payload[length - 2] || - crc[1] != payload[length - 3] || crc[0] != payload[length - 4]) { + if (actual_crc != expected_crc) { RT_TRACE(_module_rtl871x_security_c_, _drv_err_, - "rtw_wep_decrypt23a:icv error crc[3](%x)!= payload[length-1](%x) || crc[2](%x)!= payload[length-2](%x) || crc[1](%x)!= payload[length-3](%x) || crc[0](%x)!= payload[length-4](%x)\n", - crc[3], payload[length - 1], - crc[2], payload[length - 2], - crc[1], payload[length - 3], - crc[0], payload[length - 4]); + "rtw_wep_decrypt23a:icv CRC mismatch: " + "actual: %08x, expected: %08x\n", + actual_crc, expected_crc); } } @@ -714,7 +712,7 @@ int rtw_tkip_decrypt23a(struct rtw_adapter *padapter, u32 pnh; u8 rc4key[16]; u8 ttkey[16]; - u8 crc[4]; + u32 actual_crc, expected_crc; struct arc4context mycontext; int length; u32 prwskeylen; @@ -771,18 +769,14 @@ int rtw_tkip_decrypt23a(struct rtw_adapter *padapter, arcfour_init(&mycontext, rc4key, 16); arcfour_encrypt(&mycontext, payload, payload, length); - *((u32 *)crc) = le32_to_cpu(getcrc32(payload, length - 4)); + actual_crc = le32_to_cpu(getcrc32(payload, length - 4)); + expected_crc = le32_to_cpu(get_unaligned_le32(&payload[length - 4])); - if (crc[3] != payload[length - 1] || - crc[2] != payload[length - 2] || - crc[1] != payload[length - 3] || - crc[0] != payload[length - 4]) { + if (actual_crc != expected_crc) { RT_TRACE(_module_rtl871x_security_c_, _drv_err_, - "rtw_wep_decrypt23a:icv error crc[3](%x)!= payload[length-1](%x) || crc[2](%x)!= payload[length-2](%x) || crc[1](%x)!= payload[length-3](%x) || crc[0](%x)!= payload[length-4](%x)\n", - crc[3], payload[length - 1], - crc[2], payload[length - 2], - crc[1], payload[length - 3], - crc[0], payload[length - 4]); + "rtw_wep_decrypt23a:icv CRC mismatch: " + "actual: %08x, expected: %08x\n", + actual_crc, expected_crc); res = _FAIL; }