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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 2FDE9C76195 for ; Thu, 18 Jul 2019 16:22:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1080B208C0 for ; Thu, 18 Jul 2019 16:22:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727762AbfGRQWR (ORCPT ); Thu, 18 Jul 2019 12:22:17 -0400 Received: from helcar.hmeau.com ([216.24.177.18]:55502 "EHLO deadmen.hmeau.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726040AbfGRQWR (ORCPT ); Thu, 18 Jul 2019 12:22:17 -0400 Received: from gondobar.mordor.me.apana.org.au ([192.168.128.4] helo=gondobar) by deadmen.hmeau.com with esmtps (Exim 4.89 #2 (Debian)) id 1ho9Aa-00024I-9h; Fri, 19 Jul 2019 00:22:12 +0800 Received: from herbert by gondobar with local (Exim 4.89) (envelope-from ) id 1ho9AX-0006pm-Fg; Fri, 19 Jul 2019 00:22:09 +0800 Date: Fri, 19 Jul 2019 00:22:09 +0800 From: Herbert Xu To: Ard Biesheuvel Cc: Pascal Van Leeuwen , Milan Broz , Horia Geanta , "linux-crypto@vger.kernel.org" , "dm-devel@redhat.com" Subject: Re: xts fuzz testing and lack of ciphertext stealing support Message-ID: <20190718162209.keahd3nexkp5ay7l@gondor.apana.org.au> References: <20190718065223.4xaefcwjoxvujntw@gondor.apana.org.au> <20190718072154.m2umem24x4grbf6w@gondor.apana.org.au> <36e78459-1594-6d19-0ab4-95b03a6de036@gmail.com> <20190718152908.xiuze3kb3fdc7ov6@gondor.apana.org.au> <20190718155140.b6ig3zq22askmfpy@gondor.apana.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On Thu, Jul 18, 2019 at 06:19:24PM +0200, Ard Biesheuvel wrote: > > Note that for software algorithms such as the bit sliced NEON > implementation of AES, which can only operate on 8 AES blocks at a > time, doing the final 2 blocks sequentially is going to seriously > impact performance. This means whatever wrapper we invent around xex() > (or whatever we call it) should go out of its way to ensure that the > common, non-CTS case does not regress in performance, and the special > handling is only invoked when necessary (which will be never). Agreed. Cheers, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt