From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.5 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD, STOX_REPLY_TYPE shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id C99B3201A9 for ; Fri, 24 Feb 2017 20:33:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751287AbdBXUdn (ORCPT ); Fri, 24 Feb 2017 15:33:43 -0500 Received: from smtp-out-6.talktalk.net ([62.24.135.70]:37134 "EHLO smtp-out-6.talktalk.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751163AbdBXUdm (ORCPT ); Fri, 24 Feb 2017 15:33:42 -0500 Received: from PhilipOakley ([92.31.218.76]) by smtp.talktalk.net with SMTP id hMYdcFOyqgKsthMYdcZM6X; Fri, 24 Feb 2017 20:33:40 +0000 X-Originating-IP: [92.31.218.76] X-Spam: 0 X-OAuthority: v=2.2 cv=GdBVpkfL c=1 sm=1 tr=0 a=e6L6E7eW+5Nb7SO+DvSdIg==:117 a=e6L6E7eW+5Nb7SO+DvSdIg==:17 a=IkcTkHD0fZMA:10 a=1XWaLZrsAAAA:8 a=ybZZDoGAAAAA:8 a=WzfummkPaZyQDFx0aBMA:9 a=QEXdDO2ut3YA:10 a=nJcEw6yWrPvoIXZ49MH8:22 a=0RhZnL1DYvcuLYC8JZ5M:22 Message-ID: Reply-To: "Philip Oakley" From: "Philip Oakley" To: "Stefan Beller" , "Junio C Hamano" Cc: "David Lang" , "Ian Jackson" , "Joey Hess" , References: <20170223164306.spg2avxzukkggrpb@kitenet.net> <22704.19873.860148.22472@chiark.greenend.org.uk> Subject: Re: SHA1 collisions found Date: Fri, 24 Feb 2017 20:33:39 -0000 Organization: OPDS MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="UTF-8"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 X-CMAE-Envelope: MS4wfKyAqWJmn6A/ajvatChWy655NWER83KGS6Sopm7/4mm2jAfyaW4pqwT0gXcgAELmfhBnrr3YlrpEHxOTMHMKpUSxeznlrx3xd59+v0YLnNvm87tklUCN f14zM5DHn8rh54jiQh1RjafxOAahnckZiBaaBTw76AOuL6s4aqcqt0gzcmXxJ6ryBs9EapC1/ZftfkkTUCBHcewvr7F66pRMqC8FE555kPLn5mzU77/FZmSR w8+h1oPgGvG083K3QWBzbPg2yznaKLzr8AePudUj39gB4Z1F5fRnisWpx9JU64y1s3xsT3xcPTRvEguc/D929A== Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: "Stefan Beller" > On Fri, Feb 24, 2017 at 10:14 AM, Junio C Hamano > wrote: > >> you are inviting people to start using >> >> md5,54ddf8d47340e048166c45f439ce65fd >> >> as object names. > > which might even be okay for specific subsets of operations. > (e.g. all local work including staging things, making local "fixup" > commits) > > The addressing scheme should not be too hardcoded, we should rather > treat it similar to the cipher schemes in pgp. The additional complexity > that > we have is the longevity of existence of things, though. > One potential nicety of using the md5 is that it is a known `toy problem` solution that could be used to explore how things might be made to work, without any expectation that the temporary code is in any way an experimental part of regular code. Maybe. It's good to have a toy problem to work on. There are other issue to be considered as well, such as validating a transition of identical blobs and trees (at some point there will for some users be a forced update of hash of unchanged code), which probably requires two way traversal. Philip