Received: (at 25999) by debbugs.gnu.org; 9 May 2022 13:17:04 +0000 From debbugs-submit-bounces <at> debbugs.gnu.org Mon May 09 09:17:04 2022 Received: from localhost ([127.0.0.1]:56594 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>) id 1no3G3-0007kZ-T6 for submit <at> debbugs.gnu.org; Mon, 09 May 2022 09:17:04 -0400 Received: from mail-wm1-f43.google.com ([209.85.128.43]:39787) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <pixelbeat@HIDDEN>) id 1no3G1-0007jy-QT for 25999 <at> debbugs.gnu.org; Mon, 09 May 2022 09:17:02 -0400 Received: by mail-wm1-f43.google.com with SMTP id 125-20020a1c0283000000b003946c466c17so180572wmc.4 for <25999 <at> debbugs.gnu.org>; Mon, 09 May 2022 06:17:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:message-id:date:mime-version:user-agent:subject :content-language:to:references:from:in-reply-to :content-transfer-encoding; bh=IfHkMLtrCI+S2hMFkkfDNCKaoG1x92Nb+LVc3xM5lrw=; b=AlIEnxsblu9oc25Lv1DpHnuZIxFry6Idze7Mri23CCs4og8s0jp/CZ4loS+x0mn1u7 zEaRvMaJjpNH2Am0TfTeZcVAbC4ms4lGKPTMW8nU6Q/xaqobYhAWd043y9mS9hYpNUFm gThlYrXEZJC0ciTd6Z+CkpZz9SOVxz3Pbs8GwAY1/iqdCrZHPDOXabQhc6KouW9+UxCd L96MFIGTUBR1Qrxk9WN74o9pcQNhwqzZnhqFFs5wljpUyrILpKfd9Elu15KyWuaJhepb McB3Yxy/MakepQu3HCNzTl2rxcmyZDwW9a8r8viinHDAn/wA1RLBqVeENyQkMfhKY1Qg 8T6Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:message-id:date:mime-version:user-agent :subject:content-language:to:references:from:in-reply-to :content-transfer-encoding; bh=IfHkMLtrCI+S2hMFkkfDNCKaoG1x92Nb+LVc3xM5lrw=; b=2d61rgkr9iRbOCZF/0Ih/XBlHD88Feoj4FtOPEWBbxH8weNUFdmpvXNipWHiYbV4Sl 7nBzdRpXtkjOrDE/bRNOxB/5AEdWNyDXa/UPevSqchzVQaHEPtp4CVhveF5J20ftcSlT qisY11sTiYHHKlvNggt2nIC6MLoLug7Iauk9+WEvik6y/1Demx/maFqmeaFz4o39dbPG tQQE+7IbdN189W5sllqQki4ZjUWjz4T1WYJ87F9gIxNNEPnhcifO1xKO597DQtxBeT3C srd+XHXx24toXmUtAqctTCqp5xs/80LoS9XAdREUq62daRhcYTwBUpRQ7sNDPlXiCkfV 00iw== X-Gm-Message-State: AOAM533nZxOpX6wowoR5VrhkLUIjV5xqld3gyiIJ3pyrA4qLcfjoE2B4 LqKwwyQYfe9D75lrLNfHdqc= X-Google-Smtp-Source: ABdhPJwAoVdi9UDcegzYI7xnaNSl/d7uy7KDK4TORrwsQzxAqf2thAgR+nFyLDaWSee4CdB3gZjmAQ== X-Received: by 2002:a05:600c:500d:b0:394:62d1:b3fa with SMTP id n13-20020a05600c500d00b0039462d1b3famr22375681wmr.194.1652102215070; Mon, 09 May 2022 06:16:55 -0700 (PDT) Received: from [192.168.1.9] (95-44-90-175-dynamic.agg2.lod.rsl-rtd.eircom.net. [95.44.90.175]) by smtp.googlemail.com with ESMTPSA id o9-20020a5d6709000000b0020c5253d8c1sm10919799wru.13.2022.05.09.06.16.54 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 09 May 2022 06:16:54 -0700 (PDT) Message-ID: <a3c8a3f3-9262-7811-8552-47c1b85cfccf@HIDDEN> Date: Mon, 9 May 2022 14:16:53 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:97.0) Gecko/20100101 Thunderbird/97.0 Subject: Re: bug#25999: SHA1SUM: please switch to sha1dc to warn of attempted hash collision attacks Content-Language: en-US To: Christoph Anton Mitterer <calestyo@HIDDEN>, 25999 <at> debbugs.gnu.org References: <1488813374.3833386.901979264.6597C9CC@HIDDEN> <78061500d1123b0d2a782f8661e602a50b613a17.camel@HIDDEN> From: =?UTF-8?Q?P=c3=a1draig_Brady?= <P@HIDDEN> In-Reply-To: <78061500d1123b0d2a782f8661e602a50b613a17.camel@HIDDEN> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Score: 0.5 (/) X-Debbugs-Envelope-To: 25999 X-BeenThere: debbugs-submit <at> debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: <debbugs-submit.debbugs.gnu.org> List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe> List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/> List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org> List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help> List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe> Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org> X-Spam-Score: -0.5 (/) On 08/05/2022 21:19, Christoph Anton Mitterer wrote: > Hey. > > Is this still being considered? Yes it still does make sense, especially as sha1 becomes less popular over time, in which case the extra processing would matter less. thanks, Pádraig
bug-coreutils@HIDDEN:bug#25999; Package coreutils.
Full text available.Received: (at 25999) by debbugs.gnu.org; 8 May 2022 20:19:39 +0000 From debbugs-submit-bounces <at> debbugs.gnu.org Sun May 08 16:19:39 2022 Received: from localhost ([127.0.0.1]:55304 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>) id 1nnnNS-0002cM-QW for submit <at> debbugs.gnu.org; Sun, 08 May 2022 16:19:38 -0400 Received: from cockroach.ash.relay.mailchannels.net ([23.83.222.37]:30041) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <calestyo@HIDDEN>) id 1nnnNN-0002bz-4E; Sun, 08 May 2022 16:19:34 -0400 X-Sender-Id: instrampxe0y3a|x-authuser|calestyo@HIDDEN Received: from relay.mailchannels.net (localhost [127.0.0.1]) by relay.mailchannels.net (Postfix) with ESMTP id ADECD219E7; Sun, 8 May 2022 20:19:28 +0000 (UTC) Received: from cpanel-007-fra.hostingww.com (unknown [127.0.0.6]) (Authenticated sender: instrampxe0y3a) by relay.mailchannels.net (Postfix) with ESMTPA id D12A72194E; Sun, 8 May 2022 20:19:27 +0000 (UTC) ARC-Seal: i=1; s=arc-2022; d=mailchannels.net; t=1652041168; a=rsa-sha256; cv=none; b=5/IG/wbV0MebjwiOH06cW/FhVNIN/pKlmRNOaJGNUB9HBMXJTRDGfwJsrt6j+vV7TJEHkw Zp1fi4F3guDBnvKLT4qlliIgvAC4PD9cQ9PZ5uSxdqANceD/qdJFv3VAwq2wyh6PztD9Zo Dk+Nf+n5KtIwuRi/KJjfppITi21zMtGi5qPpLV6AOj/q7M2DqjxWhQm31Z9Mi56Ixbx7Sj 4GxjijYRPthQt4BqrkUsWLGEPZUobfzsAXAziDyhbxjAy7H6Q51AqIqYJYocAJ6S+Aua/m vFKutDvLOwR97VxQhluVxhlSj9wVWJ7XlXJeTl1fWyemXcRfI88c76h//fDs5A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=mailchannels.net; s=arc-2022; t=1652041168; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=3YQN+8RSIYiLAAIALeL8RA9Pf0ABqo/v3ml5AxyTcwc=; b=n2Am2aFj3Z3MwpOsERaPlzPwGOjcgY1ELiPA7Ld96zRJimOZ8JXTKWlTWnFjP2otgX9gWi URsGWA0W+93Z1dRh++osZ5U9izkrcRyzHS4fQ0Uf3/mhWat8gd5EUrg8jEgbSblaulB2mx 6XwQrdMkJ4Oqb/PjIciBHrJ/WsZqtG9ibBjIrXG0APMyWG9zHKlYZqcaKfHu/OGX0N1gES 4kFx/r93TNCcLLGIXysYwxsyvjn+gUUq0r25Y1QZRpkT7Kpta/XT5ENsz0DUlphEOXtE0g HdvdhZ9YyuGBRYB4b3EkregzvuQ6nX5T3/3siBiI30jN/i9CCoNGoTPA1senlQ== ARC-Authentication-Results: i=1; rspamd-847cd55849-8q78p; auth=pass smtp.auth=instrampxe0y3a smtp.mailfrom=calestyo@HIDDEN X-Sender-Id: instrampxe0y3a|x-authuser|calestyo@HIDDEN X-MC-Relay: Neutral X-MailChannels-SenderId: instrampxe0y3a|x-authuser|calestyo@HIDDEN X-MailChannels-Auth-Id: instrampxe0y3a X-Chemical-Shrill: 192d5bdb2761d2ff_1652041168325_149012813 X-MC-Loop-Signature: 1652041168324:3554726252 X-MC-Ingress-Time: 1652041168324 Received: from cpanel-007-fra.hostingww.com (cpanel-007-fra.hostingww.com [3.69.87.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384) by 100.112.55.199 (trex/6.7.1); Sun, 08 May 2022 20:19:28 +0000 Received: from ppp-46-244-249-74.dynamic.mnet-online.de ([46.244.249.74]:60402 helo=heisenberg.fritz.box) by cpanel-007-fra.hostingww.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from <calestyo@HIDDEN>) id 1nnnNC-0000Zt-7b; Sun, 08 May 2022 20:19:26 +0000 Message-ID: <78061500d1123b0d2a782f8661e602a50b613a17.camel@HIDDEN> Subject: Re: SHA1SUM: please switch to sha1dc to warn of attempted hash collision attacks From: Christoph Anton Mitterer <calestyo@HIDDEN> To: 25999 <at> debbugs.gnu.org Date: Sun, 08 May 2022 22:19:21 +0200 Content-Type: text/plain Content-Transfer-Encoding: 7bit User-Agent: Evolution 3.44.1-2 MIME-Version: 1.0 X-OutGoing-Spam-Status: No, score=-1.0 X-AuthUser: calestyo@HIDDEN X-Spam-Score: 1.1 (+) X-Spam-Report: Spam detection software, running on the system "debbugs.gnu.org", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hey. Is this still being considered? Thanks, Chris. Content analysis details: (1.1 points, 10.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [23.83.222.37 listed in list.dnswl.org] -0.0 T_SCC_BODY_TEXT_LINE No description available. 1.1 HAS_X_OUTGOING_SPAM_STAT Has header claiming outbound spam scan - why trust the results? X-Debbugs-Envelope-To: 25999 X-BeenThere: debbugs-submit <at> debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: <debbugs-submit.debbugs.gnu.org> List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe> List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/> List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org> List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help> List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe> Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org> X-Spam-Score: -1.0 (-) Hey. Is this still being considered? Thanks, Chris.
bug-coreutils@HIDDEN:bug#25999; Package coreutils.
Full text available.Assaf Gordon <assafgordon@HIDDEN>
to control <at> debbugs.gnu.org.
Full text available.Received: (at 25999) by debbugs.gnu.org; 7 Mar 2017 04:45:20 +0000 From debbugs-submit-bounces <at> debbugs.gnu.org Mon Mar 06 23:45:20 2017 Received: from localhost ([127.0.0.1]:43477 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>) id 1cl6zw-0000z7-Gz for submit <at> debbugs.gnu.org; Mon, 06 Mar 2017 23:45:20 -0500 Received: from midir.magicbluesmoke.com ([82.195.144.46]:49492 helo=mail.magicbluesmoke.com) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <P@HIDDEN>) id 1cl6zu-0000yz-N9 for 25999 <at> debbugs.gnu.org; Mon, 06 Mar 2017 23:45:19 -0500 Received: from localhost.localdomain (mobile-166-137-176-063.mycingular.net [166.137.176.63]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.magicbluesmoke.com (Postfix) with ESMTPSA id 195E598CD; Tue, 7 Mar 2017 04:45:16 +0000 (GMT) Subject: Re: bug#25999: SHA1SUM: please switch to sha1dc to warn of attempted hash collision attacks To: Henrique de Moraes Holschuh <hmh@HIDDEN>, 25999 <at> debbugs.gnu.org References: <1488813374.3833386.901979264.6597C9CC@HIDDEN> From: =?UTF-8?Q?P=c3=a1draig_Brady?= <P@HIDDEN> Message-ID: <992429e4-cdad-93cd-0fc8-e8cef3a3f774@HIDDEN> Date: Mon, 6 Mar 2017 20:45:11 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 In-Reply-To: <1488813374.3833386.901979264.6597C9CC@HIDDEN> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Spam-Score: 0.0 (/) X-Debbugs-Envelope-To: 25999 X-BeenThere: debbugs-submit <at> debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: <debbugs-submit.debbugs.gnu.org> List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe> List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/> List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org> List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help> List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe> Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org> X-Spam-Score: 0.0 (/) On 06/03/17 07:16, Henrique de Moraes Holschuh wrote: > This is a feature request, in light of the "shattered" attack against > SHA-1[1] published by Google. > > A drop-in replacement for sha1 exists, based on the concept of > counter-cryptanalysis[2]. This drop-in replacement can detect when the > SHA-1 hash hits the weakened internal states used by the shattered > attack. Optionally, it can also negate the > collision-resistance-weakening effect of the "shattered" attack. > > This "hardened sha1" drop-in replacement is called sha1dc (for collision > detection), and an implementation can be found at: > > https://github.com/cr-marcstevens/sha1collisiondetection > > The license for the sha1-dc library is MIT. Other noteworthy users of > sha1dc are the git scm, which will use it to _detect_ objects weakened > for easier collisions, and refuse such objects. This new version of git > has not been released yet at the time I am writing this bug report, but > the relevant patches are already in git's "pu" branch. > > It would be nice if coreutils' sha1sum would use sha1dc, and report > (either as a warning, or as an error) when an attempt at generating SHA1 > collisions is detected. > > Note that this feature request is not for sha1sum to switch to the > hardened "safe version" of sha1dc that defuses the collision attempts, > but rather that sha1dc be used to detect and warn the user about the > specially crafted input data that makes the "shattered" attack feasible. > > I have no strong opinions on whether sha1sum should abort or just warn > when an attempted collision is detected. I also have no strong opinions > whether it should use "safe mode" or not, as long as it *does* warn the > user when an attempted collision is detected... only, I feel "safe mode" > behavior should be optional (I have no strong opinions on whether it > should be enabled by default or not). > > [1] https://shattered.it/ > [2] http://eprint.iacr.org/2017/173/20170228:105224 > Interesting. I agree the "safe version" is less interesting as one can use sha3 or blake2 with the same length as sha1, for about the same compatibility but greater protection. As for detection, I suppose we should by default enable this with sha1sum --check, because: - sha1sum should be as safe as possible by default - we don't care that much about sha1 perf since it's deprecated - false positive probability is smaller than 2^-90 I wonder is there similar analysis possible with md5sum? As for licensing, we could probably integrate it as we do already for src/blake2/ thanks, Pádraig
bug-coreutils@HIDDEN:bug#25999; Package coreutils.
Full text available.Received: (at submit) by debbugs.gnu.org; 6 Mar 2017 15:16:35 +0000 From debbugs-submit-bounces <at> debbugs.gnu.org Mon Mar 06 10:16:35 2017 Received: from localhost ([127.0.0.1]:42931 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>) id 1ckuNG-0006BG-N6 for submit <at> debbugs.gnu.org; Mon, 06 Mar 2017 10:16:35 -0500 Received: from eggs.gnu.org ([208.118.235.92]:42811) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from <hmh@HIDDEN>) id 1ckuNE-0006B2-KI for submit <at> debbugs.gnu.org; Mon, 06 Mar 2017 10:16:33 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from <hmh@HIDDEN>) id 1ckuN8-0008Gc-CH for submit <at> debbugs.gnu.org; Mon, 06 Mar 2017 10:16:27 -0500 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on eggs.gnu.org X-Spam-Level: X-Spam-Status: No, score=0.8 required=5.0 tests=BAYES_50,T_DKIM_INVALID autolearn=disabled version=3.3.2 Received: from lists.gnu.org ([2001:4830:134:3::11]:55732) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from <hmh@HIDDEN>) id 1ckuN8-0008GX-8Z for submit <at> debbugs.gnu.org; Mon, 06 Mar 2017 10:16:26 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33765) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from <hmh@HIDDEN>) id 1ckuN6-00007d-S3 for bug-coreutils@HIDDEN; Mon, 06 Mar 2017 10:16:26 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from <hmh@HIDDEN>) id 1ckuN3-0008CC-LT for bug-coreutils@HIDDEN; Mon, 06 Mar 2017 10:16:24 -0500 Received: from out4-smtp.messagingengine.com ([66.111.4.28]:38697) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from <hmh@HIDDEN>) id 1ckuN3-0008BE-Ec for bug-coreutils@HIDDEN; Mon, 06 Mar 2017 10:16:21 -0500 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id 7F7EF20B0D for <bug-coreutils@HIDDEN>; Mon, 6 Mar 2017 10:16:14 -0500 (EST) Received: from web3 ([10.202.2.213]) by compute6.internal (MEProxy); Mon, 06 Mar 2017 10:16:14 -0500 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-sender :x-me-sender:x-sasl-enc; s=smtpout; bh=sJxHgHRPy7sPtvt6WZPVEo8av mA=; b=evztVbm9sHMu7+SwEcvO/I7HWwquOvUF4RKypG4aDJiEH1FQhPepSRn+w WmbkeeDrXfa+cGY92gsh3bBv2DvSZDO6bcYGTG8dnVybHPnNjerdyrjMn6RRuj6i U1QCoLh36kIztzdJpfN+3oREys6dlgxA2NmPQ3feKNGwLTjUAA= X-ME-Sender: <xms:Pn29WEJLJLiBS-EgPKvTdK96lGovgepTq1rGL8EKs6U46msCjf_dyg> Received: by mailuser.nyi.internal (Postfix, from userid 99) id 5EDD99EBC1; Mon, 6 Mar 2017 10:16:14 -0500 (EST) Message-Id: <1488813374.3833386.901979264.6597C9CC@HIDDEN> From: Henrique de Moraes Holschuh <hmh@HIDDEN> To: bug-coreutils@HIDDEN MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" X-Mailer: MessagingEngine.com Webmail Interface - ajax-9f47d516 Date: Mon, 06 Mar 2017 12:16:14 -0300 Subject: SHA1SUM: please switch to sha1dc to warn of attempted hash collision attacks X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 2001:4830:134:3::11 X-Spam-Score: -5.0 (-----) X-Debbugs-Envelope-To: submit X-BeenThere: debbugs-submit <at> debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: <debbugs-submit.debbugs.gnu.org> List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe> List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/> List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org> List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help> List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>, <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe> Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org> X-Spam-Score: -5.0 (-----) This is a feature request, in light of the "shattered" attack against SHA-1[1] published by Google. A drop-in replacement for sha1 exists, based on the concept of counter-cryptanalysis[2]. This drop-in replacement can detect when the SHA-1 hash hits the weakened internal states used by the shattered attack. Optionally, it can also negate the collision-resistance-weakening effect of the "shattered" attack. This "hardened sha1" drop-in replacement is called sha1dc (for collision detection), and an implementation can be found at: https://github.com/cr-marcstevens/sha1collisiondetection The license for the sha1-dc library is MIT. Other noteworthy users of sha1dc are the git scm, which will use it to _detect_ objects weakened for easier collisions, and refuse such objects. This new version of git has not been released yet at the time I am writing this bug report, but the relevant patches are already in git's "pu" branch. It would be nice if coreutils' sha1sum would use sha1dc, and report (either as a warning, or as an error) when an attempt at generating SHA1 collisions is detected. Note that this feature request is not for sha1sum to switch to the hardened "safe version" of sha1dc that defuses the collision attempts, but rather that sha1dc be used to detect and warn the user about the specially crafted input data that makes the "shattered" attack feasible. I have no strong opinions on whether sha1sum should abort or just warn when an attempted collision is detected. I also have no strong opinions whether it should use "safe mode" or not, as long as it *does* warn the user when an attempted collision is detected... only, I feel "safe mode" behavior should be optional (I have no strong opinions on whether it should be enabled by default or not). [1] https://shattered.it/ [2] http://eprint.iacr.org/2017/173/20170228:105224 -- Henrique de Moraes Holschuh <hmh@HIDDEN>
Henrique de Moraes Holschuh <hmh@HIDDEN>:bug-coreutils@HIDDEN.
Full text available.bug-coreutils@HIDDEN:bug#25999; Package coreutils.
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