Return-path: Received: from wf-out-1314.google.com ([209.85.200.171]:14355 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758930AbZAIB2m (ORCPT ); Thu, 8 Jan 2009 20:28:42 -0500 Received: by wf-out-1314.google.com with SMTP id 27so9575321wfd.4 for ; Thu, 08 Jan 2009 17:28:41 -0800 (PST) Subject: Re: Thoughts about the b43 RNG From: Harvey Harrison To: Michael Buesch Cc: bcm43xx-dev@lists.berlios.de, linux-wireless@vger.kernel.org In-Reply-To: <200901090211.03937.mb@bu3sch.de> References: <200901090211.03937.mb@bu3sch.de> Content-Type: text/plain Date: Thu, 08 Jan 2009 17:28:39 -0800 Message-Id: <1231464519.5715.32.camel@brick> (sfid-20090109_022855_239051_DF872052) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, 2009-01-09 at 02:11 +0100, Michael Buesch wrote: > I was doing some random tests on the b43 hardware RNG. > These are the results. > > I patched the firmware to not access the RNG register anymore. > The unpatched firmware does two things. It reads the RNG register to get random values > and it writes 0 to the register every now and then for whatever reason. > Both reads and writes were patched out during my test. So the driver was > the only one accessing the RNG. > > This is the result of reading a few bytes from the RNG with the patched fw: > I'm not sure about this. There aren't any obvious patterns. > But maybe I'm just blind. Does somebody else see some pattern or > has some RNG test program to recognize such patterns? > > So let's do another test. Let's modify the previous test to > write 0xFFFF instead of 0: > NIST has a pretty good test suite I think. Harvey