From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Geoffrey Irving" Subject: Re: About git and the use of SHA-1 Date: Tue, 29 Apr 2008 14:39:46 -0700 Message-ID: <7f9d599f0804291439m6f5dd242jb31b84e1a0205cdc@mail.gmail.com> References: <20080429124152.GB6160@dpotapov.dyndns.org> <7f9d599f0804290859y6a579302m5db9f7f827b320a4@mail.gmail.com> <7f9d599f0804291048n2c706f3amdf159ffe86bdbc8@mail.gmail.com> <7f9d599f0804291102j4a30c344h18d12d03a6d5953b@mail.gmail.com> <7f9d599f0804291331v2f44bee1y29c1580d68a3107a@mail.gmail.com> <20080429205031.GA14547@frsk.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Daniel Barkalow" , "Nicolas Pitre" , "Andreas Ericsson" , "Dmitry Potapov" , "Henrik Austad" , git@vger.kernel.org To: "Fredrik Skolmli" X-From: git-owner@vger.kernel.org Tue Apr 29 23:40:36 2008 connect(): Connection refused Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1JqxYx-00034f-KL for gcvg-git-2@gmane.org; Tue, 29 Apr 2008 23:40:36 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752916AbYD2Vju (ORCPT ); Tue, 29 Apr 2008 17:39:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751448AbYD2Vjt (ORCPT ); Tue, 29 Apr 2008 17:39:49 -0400 Received: from po-out-1718.google.com ([72.14.252.157]:11268 "EHLO po-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752791AbYD2Vjs (ORCPT ); Tue, 29 Apr 2008 17:39:48 -0400 Received: by po-out-1718.google.com with SMTP id b23so78368poe.1 for ; Tue, 29 Apr 2008 14:39:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; bh=OSbM/rB4nw84zos6PxBS+XD8KzuACJ1wovMky1nCNIA=; b=RRJ296O/BtPu7PeY7Gc90uDR8CXwT1tinpKCN/AcWPFKWuEl+qtXqRdblNFTDI5HcNEdcLvMeUZlhBiJ3tSvmgC0kgm8DHJKsJqkg1msMPxoqKozJ8foXuJMr6Nk441sd0ooOrkZ5HOQtye36eUypbyHpI5JKGZtYYJyVfj7KQs= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=FOCkFM5UBzzemeOfxeMovmh3ExI+ANwAy6tPwrVNB7aNvMDv5obOa7fkNIX8qbQfPRPLtZ4MLkGGLrRZ3/WbM4iRCsHfqoh6/fynoSV0GHHNxISfsEFNC0LcBJDo6WmI9t7rkhPuiVrcOkOU0HmdT6WyQ0NNSDh7SaIdqJMPtao= Received: by 10.140.165.21 with SMTP id n21mr3422792rve.45.1209505186939; Tue, 29 Apr 2008 14:39:46 -0700 (PDT) Received: by 10.140.178.16 with HTTP; Tue, 29 Apr 2008 14:39:46 -0700 (PDT) In-Reply-To: <20080429205031.GA14547@frsk.net> Content-Disposition: inline X-Google-Sender-Auth: e500f8f6d050d465 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Tue, Apr 29, 2008 at 1:50 PM, Fredrik Skolmli wrote: > On Tue, Apr 29, 2008 at 01:31:51PM -0700, Geoffrey Irving wrote: > > > I sincerely hope that pdf/postscript don't allow the internal > > rendering code to branch based on the current date. That would be an > > absurd security hole, and would indeed make you entirely correct. If > > you actually know that it is possible to write that in postscript, I > > would very much want to see an example. > > Have a look at > > * http://th.informatik.uni-mannheim.de/People/Lucks/HashCollisions/letter_of_rec.ps > vs > * http://th.informatik.uni-mannheim.de/People/Lucks/HashCollisions/order.ps > > both found on a website[1] already mentioned[2] in this thread. :-) > > [1]: http://th.informatik.uni-mannheim.de/People/Lucks/HashCollisions/ > [2]: http://marc.info/?l=git&m=120949349923584&w=2 This is an example of a hash collision, not conditional rendering based on the current date. I.e., you didn't actually read my email or the email I was replying to. :) Geoffrey