Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267587AbTGWKpx (ORCPT ); Wed, 23 Jul 2003 06:45:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268047AbTGWKpx (ORCPT ); Wed, 23 Jul 2003 06:45:53 -0400 Received: from arnor.apana.org.au ([203.14.152.115]:57608 "EHLO arnor.me.apana.org.au") by vger.kernel.org with ESMTP id S267587AbTGWKpw (ORCPT ); Wed, 23 Jul 2003 06:45:52 -0400 Date: Wed, 23 Jul 2003 20:59:03 +1000 To: "David S. Miller" Cc: a.marsman@aYniK.com, alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org Subject: Re: 2.4.22-pre7: are security issues solved? Message-ID: <20030723105903.GA2582@gondor.apana.org.au> References: <20030723033505.145db6b8.davem@redhat.com> <20030723104753.GA2479@gondor.apana.org.au> <20030723035022.23a75bc5.davem@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030723035022.23a75bc5.davem@redhat.com> User-Agent: Mutt/1.5.4i From: Herbert Xu Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1341 Lines: 37 On Wed, Jul 23, 2003 at 03:50:22AM -0700, David S. Miller wrote: > > > It's much smaller if you didn't know that it was at most 7 characters > > long. However, if you did know the upper bound, or you were just > > brute forcing all passwords starting from 1 character, then the > > difference is relatively minor. This is because > > > > n + n^2 + n^3 + n^4 + n^5 + n^6 > > > > is much smaller than n^7 where n is something like 62 for a reasonable > > password. > > "7" in my example is an arbitrary number, increase it to any larger > number you like. Well, as m gets larger, the number (n + n^2 + ... + n^(m-1)) / n^m tends to 1 / (n - 1). In other words, if you can break n^m, then you can probably break n + n^2 + ... + n^m Anyway, I'm not that bothered with making /proc/tty/driver root-only, even if it is only for what seems to me to be dubious reasons. -- Debian GNU/Linux 3.0 is out! ( http://www.debian.org/ ) Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/