From owner-freebsd-security Sat Dec 29 22: 2:51 2001 Delivered-To: freebsd-security@freebsd.org Received: from gw.nectar.cc (gw.nectar.cc [208.42.49.153]) by hub.freebsd.org (Postfix) with ESMTP id ED52037B419 for ; Sat, 29 Dec 2001 22:02:48 -0800 (PST) Received: from madman.nectar.cc (madman.nectar.cc [10.0.1.111]) by gw.nectar.cc (Postfix) with ESMTP id 5FE913B; Sun, 30 Dec 2001 00:02:48 -0600 (CST) Received: (from nectar@localhost) by madman.nectar.cc (8.11.6/8.11.6) id fBU62mZ80493; Sun, 30 Dec 2001 00:02:48 -0600 (CST) (envelope-from nectar) Date: Sun, 30 Dec 2001 00:02:48 -0600 From: "Jacques A. Vidrine" To: Allen Landsidel Cc: Rik , Ryan Thompson , freebsd-security@FreeBSD.ORG Subject: Re: MD5 password salt calculation Message-ID: <20011230060248.GA80453@madman.nectar.cc> Mail-Followup-To: "Jacques A. Vidrine" , Allen Landsidel , Rik , Ryan Thompson , freebsd-security@FreeBSD.ORG References: <5.1.0.14.0.20011230000743.00a91a80@rfnj.org> <20011229133456.J99302-100000@catalyst.sasknow.net> <20011229133456.J99302-100000@catalyst.sasknow.net> <5.1.0.14.0.20011230000743.00a91a80@rfnj.org> <5.1.0.14.0.20011230002742.00afd4b8@rfnj.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5.1.0.14.0.20011230002742.00afd4b8@rfnj.org> User-Agent: Mutt/1.3.23.1i X-Url: http://www.nectar.cc/ Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Sun, Dec 30, 2001 at 12:58:08AM -0500, Allen Landsidel wrote: > Using something like strftime(3) defeats this, depending on the format used > in the call. If you have 256 possible salts, then an attacker may be > dissuaded from generating the lookup. Actually, even really isn't enough salt, and is one of the several problems with the traditional UNIX crypt scheme. > If you only have 24 (say strftime > was called to generate a normal human-readable time, and the two characters > for the hour were used) then the purpose behind the salt is entirely > defeated, and may as well be left off just to make the code cleaner. Yes, that would be bad. But that's not what the original poster described. Cheers, -- Jacques A. Vidrine http://www.nectar.cc/ NTT/Verio SME . FreeBSD UNIX . Heimdal Kerberos jvidrine@verio.net . nectar@FreeBSD.org . nectar@kth.se To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message