From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: Hash algorithm choice Date: Sun, 9 Aug 2009 11:35:01 -0700 (PDT) Message-ID: References: <7vljls986b.fsf@alter.siamese.dyndns.org> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Junio C Hamano , Jerome Baum , git@vger.kernel.org To: Sverre Rabbelier X-From: git-owner@vger.kernel.org Sun Aug 09 20:35:20 2009 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 1MaDEk-00054l-6m for gcvg-git-2@gmane.org; Sun, 09 Aug 2009 20:35:18 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752700AbZHISfI (ORCPT ); Sun, 9 Aug 2009 14:35:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752645AbZHISfI (ORCPT ); Sun, 9 Aug 2009 14:35:08 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:41426 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752640AbZHISfH (ORCPT ); Sun, 9 Aug 2009 14:35:07 -0400 Received: from imap1.linux-foundation.org (imap1.linux-foundation.org [140.211.169.55]) by smtp1.linux-foundation.org (8.14.2/8.13.5/Debian-3ubuntu1.1) with ESMTP id n79IZ2OE026171 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 9 Aug 2009 11:35:03 -0700 Received: from localhost (localhost [127.0.0.1]) by imap1.linux-foundation.org (8.13.5.20060308/8.13.5/Debian-3ubuntu1.1) with ESMTP id n79IZ1Rv026519; Sun, 9 Aug 2009 11:35:01 -0700 X-X-Sender: torvalds@localhost.localdomain In-Reply-To: User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) X-Spam-Status: No, hits=-3.465 required=5 tests=AWL,BAYES_00 X-Spam-Checker-Version: SpamAssassin 3.2.4-osdl_revision__1.47__ X-MIMEDefang-Filter: lf$Revision: 1.188 $ X-Scanned-By: MIMEDefang 2.63 on 140.211.169.13 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Sun, 9 Aug 2009, Sverre Rabbelier wrote: > > Wouldn't the transport code also have to be modified? I assume git's > integrity checking would yell at if you gave it commits with > non-sha1-hashes and have no way to tell it that that hash was > calculated with a non-sha1-hash at clone time? Well, if you start introducing new hashes, the assumption is that all git's that access it would have to be updated. You certainly could never pull/push between git versions that don't know about each others hashes. But you _can_ autodetect the hash mechanism (simple: just try them all on the first object you encounter) Linus