From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9543C433DB for ; Thu, 21 Jan 2021 05:41:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56F172389B for ; Thu, 21 Jan 2021 05:41:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725986AbhAUFlN (ORCPT ); Thu, 21 Jan 2021 00:41:13 -0500 Received: from pegase1.c-s.fr ([93.17.236.30]:33291 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727307AbhAUFf4 (ORCPT ); Thu, 21 Jan 2021 00:35:56 -0500 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4DLrgs5Dygz9tylG; Thu, 21 Jan 2021 06:35:05 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id UHuL7YWFM_p1; Thu, 21 Jan 2021 06:35:05 +0100 (CET) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4DLrgs42TKz9txsL; Thu, 21 Jan 2021 06:35:05 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 5F5BA8B771; Thu, 21 Jan 2021 06:35:06 +0100 (CET) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id LKB-aJWdnlVp; Thu, 21 Jan 2021 06:35:06 +0100 (CET) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id F27398B75E; Thu, 21 Jan 2021 06:35:05 +0100 (CET) Subject: Re: [PATCH 1/2] crypto: talitos - Work around SEC6 ERRATA (AES-CTR mode data size error) To: Ard Biesheuvel Cc: Herbert Xu , "David S. Miller" , Linux Crypto Mailing List , Linux Kernel Mailing List , "open list:LINUX FOR POWERPC (32-BIT AND 64-BIT)" References: <4b7a870573f485b9fea496b13c9b02d86dd97314.1611169001.git.christophe.leroy@csgroup.eu> From: Christophe Leroy Message-ID: <6b804eff-bc9f-5e05-d479-f398de4e2b30@csgroup.eu> Date: Thu, 21 Jan 2021 06:35:06 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 20/01/2021 à 23:23, Ard Biesheuvel a écrit : > On Wed, 20 Jan 2021 at 19:59, Christophe Leroy > wrote: >> >> Talitos Security Engine AESU considers any input >> data size that is not a multiple of 16 bytes to be an error. >> This is not a problem in general, except for Counter mode >> that is a stream cipher and can have an input of any size. >> >> Test Manager for ctr(aes) fails on 4th test vector which has >> a length of 499 while all previous vectors which have a 16 bytes >> multiple length succeed. >> >> As suggested by Freescale, round up the input data length to the >> nearest 16 bytes. >> >> Fixes: 5e75ae1b3cef ("crypto: talitos - add new crypto modes") >> Signed-off-by: Christophe Leroy > > Doesn't this cause the hardware to write outside the given buffer? Only the input length is modified. Not the output length. The ERRATA says: The input data length (in the descriptor) can be rounded up to the nearest 16B. Set the data-in length (in the descriptor) to include X bytes of data beyond the payload. Set the data-out length to only output the relevant payload (don't need to output the padding). SEC reads from memory are not destructive, so the extra bytes included in the AES-CTR operation can be whatever bytes are contiguously trailing the payload.