From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932199AbXLTW1x (ORCPT ); Thu, 20 Dec 2007 17:27:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755614AbXLTW1m (ORCPT ); Thu, 20 Dec 2007 17:27:42 -0500 Received: from torres.zugschlus.de ([85.214.68.41]:54239 "EHLO torres.zugschlus.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753192AbXLTW1k (ORCPT ); Thu, 20 Dec 2007 17:27:40 -0500 Date: Thu, 20 Dec 2007 23:27:38 +0100 From: Marc Haber To: linux-kernel@vger.kernel.org Subject: Re: Why does reading from /dev/urandom deplete entropy so much? Message-ID: <20071220222738.GA24489@torres.zugschlus.de> References: <20071204114125.GA17310@torres.zugschlus.de> <20071204161811.GB15974@stusta.de> <47584E35.7030409@tmr.com> <20071208220345.GE20441@stusta.de> <475EAFF9.9020405@tmr.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <475EAFF9.9020405@tmr.com> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 11, 2007 at 10:42:49AM -0500, Bill Davidsen wrote: > The original point was that urandom draws entropy from random, and that > it is an an inobvious and unintentional drain on the entropy pool. At > least that's how I read it. And you are reading it correct. At least one of the major TLS libraries does it this way, putting unnecessary stress on the kernel entropy pool. While I now consider this a bug in the library, there surely are gazillions of similiarily flawed applications out there in the wild. Greetings Marc -- ----------------------------------------------------------------------------- Marc Haber | "I don't trust Computers. They | Mailadresse im Header Mannheim, Germany | lose things." Winona Ryder | Fon: *49 621 72739834 Nordisch by Nature | How to make an American Quilt | Fax: *49 3221 2323190