From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61840C432BE for ; Thu, 19 Aug 2021 05:18:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3742061130 for ; Thu, 19 Aug 2021 05:18:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229804AbhHSFSl (ORCPT ); Thu, 19 Aug 2021 01:18:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:54548 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229451AbhHSFSk (ORCPT ); Thu, 19 Aug 2021 01:18:40 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AFD9761107; Thu, 19 Aug 2021 05:18:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629350285; bh=eUe4iHnO0QHSuRxWzei4ahFKR+9XbVenRz1m8RYT/Po=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YAxEpkeMOOlK+qVLQkf/bw0q39y8+yKlOzTlwmF4dZ2BQaF03yq0t3lgO29d3NuRx ta/DGg9tUOjujlyFjUNE01uxBdwjAW4i8n/J1xy9MbM8/B7RKksI4tDPvtu+h9nDLz w+OA6QaSSNRwHlbdyozyguXwQWd1efrSBoqwj7xv+8Hd0IrCtKom2MOAHEpXMGcH2c Bxa0kP0F9ZWvMRj0e3EIGlpoyk6YskjrZc2etlbIgq5CR7yJ+N8DnAhOiKeCeF9ntH Tlcz3wnrI5eTZwmYFVW/i2vOZugfWZfNnxb631vcykVm3Bqtgj4nCyfiDhONSMXxDZ KX3j8igFhCS1g== Date: Wed, 18 Aug 2021 22:18:03 -0700 From: Eric Biggers To: Andrew Bartlett Cc: Jeremy Allison , Steve French , linux-cifs , Herbert Xu , samba-technical , David Howells , Steve French , keyrings@vger.kernel.org, Linux Crypto Mailing List , Ard Biesheuvel , Denis Kenzior Subject: Re: [PATCH 0/2] crypto: remove MD4 generic shash Message-ID: References: <20210818144617.110061-1-ardb@kernel.org> <946591db-36aa-23db-a5c4-808546eab762@gmail.com> <24606605-71ae-f918-b71a-480be7d68e43@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org On Thu, Aug 19, 2021 at 03:49:14PM +1200, Andrew Bartlett wrote: > I know neither MD4 nor HMAC-MD5 is not flavour of the month any more, > with good reason, but we would not want to go with way of NFSv4 which > is, as I understand it, full Kerberos or bust (so folks choose no > protection). I'm not sure you understand how embarrassing it is to still be using these algorithms. MD4 has been broken for over 25 years, and better algorithms have been recommended for 29 years. Similarly MD5 has been broken for 16 years and better algorithms have been recommended for 25 years (though granted, HMAC-MD5 is more secure than plain MD5 when properly used). Meanwhile SHA-2 is 20 years old and is still considered secure. So this isn't something that changes every month -- we're talking about no one bothering to do anything in 30 years. Of course, if cryptography isn't actually applicable to the use case, then cryptography shouldn't be used at all. - Eric