Return-path: Received: from py-out-1112.google.com ([64.233.166.176]:46434 "EHLO py-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965455AbXBMBJS (ORCPT ); Mon, 12 Feb 2007 20:09:18 -0500 Received: by py-out-1112.google.com with SMTP id a29so940407pyi for ; Mon, 12 Feb 2007 17:09:17 -0800 (PST) Message-ID: <1ba2fa240702121709s3833aa9ajb50ed0b4fb5ce0c3@mail.gmail.com> Date: Tue, 13 Feb 2007 03:09:17 +0200 From: "Tomas Winkler" To: "Michael Buesch" Subject: Re: d80211: current TKIP hwcrypto implementation seems to be broken Cc: "Jouni Malinen" , "Jiri Benc" , linux-wireless@vger.kernel.org In-Reply-To: <200702130133.11690.mb@bu3sch.de> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed References: <200702041344.19117.mb@bu3sch.de> <200702130110.02658.mb@bu3sch.de> <1ba2fa240702121619x259f546dga2bebefbe24bf1d3@mail.gmail.com> <200702130133.11690.mb@bu3sch.de> Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2/13/07, Michael Buesch wrote: > On Tuesday 13 February 2007 01:19, Tomas Winkler wrote: > > > HW doesn't scramble it. So when d80211 receives the packet it can > > > _then_ generate the key. There's no point in precomputing it. > > > > For past packets you've already computed it so why do it again? So > > you keep 2 phas1 keys one old and one current. When sequence numbers > > advance sufficiently you discard the old one and compute the new one > > in a spare time. Something like double buffer. > > Ah, now I see. We are talking about two different things. > You are talking about the TX key and I am talking about > the RX key. We could probably cache the TX key to avoid the > key computation on every TX. That's right. But I don't even have > it working, yet, so optimization is not my worry, yet. :) > But yes, that could be an optimization to be done. No RX. phase1 is not computed on every packet, phase2 is but this is usually done be HW. > -- > Greetings Michael. >