From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261574AbVAGUxG (ORCPT ); Fri, 7 Jan 2005 15:53:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261557AbVAGUvG (ORCPT ); Fri, 7 Jan 2005 15:51:06 -0500 Received: from pagoda.mtholyoke.edu ([138.110.30.68]:13466 "EHLO pagoda.mtholyoke.edu") by vger.kernel.org with ESMTP id S261589AbVAGUui (ORCPT ); Fri, 7 Jan 2005 15:50:38 -0500 From: Ron Peterson Date: Fri, 7 Jan 2005 15:50:31 -0500 To: Robert Love Cc: linux-kernel@vger.kernel.org Subject: Re: /dev/random vs. /dev/urandom Message-ID: <20050107205031.GA14599@mtholyoke.edu> References: <20050107190536.GA14205@mtholyoke.edu> <1105126843.9311.41.camel@betsy.boston.ximian.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1105126843.9311.41.camel@betsy.boston.ximian.com> Organization: Mount Holyoke College X-Operating-System: Debian GNU/Linux User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 07, 2005 at 02:40:43PM -0500, Robert Love wrote: > On Fri, 2005-01-07 at 14:05 -0500, Ron Peterson wrote: > > > read( fd, dat, RAND_LEN ); > > for( i = 0; i < RAND_LEN; i++ ) { > > dat[i] = (dat[i] & 0x07) + '0'; > > } > > Your problem is probably because read() need not actually read RAND_LEN > bytes. Particularly with /dev/random, since it will only return bytes > up to the entropy estimate. But you assume it read RAND_LEN, when those > are unread. And possibly zero. So that is probably your bug. > > The AND makes zero sense, either. > > Just use dd(1). Ah, thanks! (to you and everyone else.) (I can't use dd because I want to use the value to feed gmp_randseed from gmp library. I need the AND to create the proper ascii code for a numeral.) Best. -- Ron Peterson Network & Systems Manager Mount Holyoke College http://www.mtholyoke.edu/~rpeterso