From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glen Turner Subject: Re: [PATCH] drivers/net: remove network drivers' last few uses of IRQF_SAMPLE_RANDOM Date: Mon, 26 May 2008 00:39:49 +0930 Message-ID: <1211728189.5913.71.camel@andromache> References: <482C7B18.6060003@garzik.org> <482C7E53.3050300@hp.com> <482C8184.2030906@garzik.org> <482C8550.5000909@intel.com> <482C8D4D.3040702@garzik.org> <20080516132107.GA11304@csclub.uwaterloo.ca> <20080516161029.44ded734@core> <20080516173610.GA27126@csclub.uwaterloo.ca> <20080516191125.46f59ad6@core> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Alan Cox , Lennart Sorensen , Jeff Garzik , "Kok, Auke" , Rick Jones , "Brandeburg, Jesse" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Chris Peterson Return-path: Received: from eth6445.sa.adsl.internode.on.net ([150.101.30.44]:33774 "EHLO aix.gdt.id.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753772AbYEYPLN (ORCPT ); Sun, 25 May 2008 11:11:13 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Fri, 2008-05-16 at 21:55 -0700, Chris Peterson wrote: > * network drivers could use IRQF_SAMPLE_URANDOM Is it permissable for /dev/urandom to degrade to be externally influenced by a hostile party? For example, /dev/random has run out. So the output of /dev/urandom is now determined by previous values of /dev/random. I then send in a stack of network packets at regular intervals. So the output of /dev/urandom is now greatly determined by those packets. My search space for the resulting key is small since /dev/urandom appears to be random, but in fact is periodic. I'll also note that there is a huge number of periodic packets seen by hosts on quiet networks -- such as a preparation VLAN where a system administrator might choose to run up a new machine.