Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id A76C12C for ; Tue, 3 Jan 2017 03:33:11 +0000 (UTC) X-Greylist: delayed 00:05:01 by SQLgrey-1.7.6 Received: from dmz-mailsec-scanner-6.mit.edu (dmz-mailsec-scanner-6.mit.edu [18.7.68.35]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 359EA180 for ; Tue, 3 Jan 2017 03:33:11 +0000 (UTC) X-AuditID: 12074423-043ff7000000401a-1a-586b1a470fd6 Received: from mailhub-auth-4.mit.edu ( [18.7.62.39]) (using TLS with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by (Symantec Messaging Gateway) with SMTP id DD.35.16410.74A1B685; Mon, 2 Jan 2017 22:28:09 -0500 (EST) Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) by mailhub-auth-4.mit.edu (8.13.8/8.9.2) with ESMTP id v033S7F6025259 for ; Mon, 2 Jan 2017 22:28:07 -0500 Received: from mail-wm0-f43.google.com (mail-wm0-f43.google.com [74.125.82.43]) (authenticated bits=0) (User authenticated as jlrubin@ATHENA.MIT.EDU) by outgoing.mit.edu (8.13.8/8.12.4) with ESMTP id v033S5XU008953 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT) for ; Mon, 2 Jan 2017 22:28:06 -0500 Received: by mail-wm0-f43.google.com with SMTP id m1so51233280wme.0 for ; Mon, 02 Jan 2017 19:28:06 -0800 (PST) X-Gm-Message-State: AIkVDXJX8lEK7ffkqhOFolKFzdoOu5RNQ5kwvkocVhKC4cq8SPZtqaiHtPcGKcJB/DiRNDbQjl5AV8v1dZjULg== X-Received: by 10.28.20.70 with SMTP id 67mr48992274wmu.102.1483414084877; Mon, 02 Jan 2017 19:28:04 -0800 (PST) MIME-Version: 1.0 Received: by 10.194.23.8 with HTTP; Mon, 2 Jan 2017 19:27:44 -0800 (PST) In-Reply-To: <400152B9-1838-432A-829E-13E4FC54320C@gmail.com> References: <400152B9-1838-432A-829E-13E4FC54320C@gmail.com> From: Jeremy Date: Mon, 2 Jan 2017 22:27:44 -0500 X-Gmail-Original-Message-ID: Message-ID: To: Steve Davis , Bitcoin Protocol Discussion Content-Type: multipart/alternative; boundary=001a1145a8369584950545284149 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrPKsWRmVeSWpSXmKPExsUixG6nrusplR1hcGEHh0XTa1sHRo/fPyYz BjBGcdmkpOZklqUW6dslcGXc2vKcvaBTo2JbxyyWBsZVKl2MnBwSAiYSC9fuZOxi5OIQEmhj krjZcY0NJCEkcIdRYuYyM4jEeyaJxqNv2SCc+YwSTTMOsEO050i0tpyGsoskXr+cAmbzCghK nJz5hAVikofE+Zl7mUBsTgFbia+HZjNDDGpllPix4QzQbg4ONgE5iQ+/TEFqWARUJLqefmKF mJkocWn9FmaImQES+7a/YQSxhQWMJLb8vQg2U0SgTuJSaweYzSzgJTH18S3mCYxCs5CcMQtJ ahbQNmYBdYn184QgwtoSyxa+Zoaw1SRub7vKjiy+gJFtFaNsSm6Vbm5iZk5xarJucXJiXl5q ka6ZXm5miV5qSukmRnAsuCjvYHzZ532IUYCDUYmHtyMqK0KINbGsuDL3EKMkB5OSKG80Q3aE EF9SfkplRmJxRnxRaU5q8SFGCQ5mJRHeCxJAOd6UxMqq1KJ8mJQ0B4uSOO+lTPcIIYH0xJLU 7NTUgtQimKwMB4eSBC+jJFCjYFFqempFWmZOCUKaiYMTZDgP0PC5YMOLCxJzizPTIfKnGI05 pr1b+JSJY0fnmqdMQix5+XmpUuK8k0FKBUBKM0rz4KaB0plXbZD2K0ZxoOeEebeAVPEAUyHc vFdAq5iAVn2NSwdZVZKIkJJqYMxWYS6uLi6f4t97+c2t/x7y61k4qzfUHLTdsGTanzifMDFr v+0VRw2lJzn+vtxfFVLf2jN70Z+9bVc9LHbfz//Jt0Y+M+GahmDuklUatz+FHApJjIm/LMh2 vals/0Idr8dfzPX6FgaJ57Qo7eU6e2HOz3h7pTj2FRM/vArSP7TOr819y90prUosxRmJhlrM RcWJADu/eBVCAwAA X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00,HTML_MESSAGE, RCVD_IN_DNSWL_MED,RP_MATCHES_RCVD autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Subject: Re: [bitcoin-dev] Script Abuse Potential? X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 03 Jan 2017 03:33:11 -0000 --001a1145a8369584950545284149 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable It is an unfortunate script, but can't actually =E2=80=8Bdo that much =E2=80=8B it seems=E2=80=8B . The MAX_SCRIPT_ELEMENT_SIZE =3D 520 Bytes. =E2=80=8B Thus, it would seem the worst you could do with this would be to (10000-520*2)*520*2 bytes ~=3D~ 10 MB. =E2=80=8BMuch more concerning would be the op_dup/op_cat style bug, which u= nder a similar script =E2=80=8Bwould certainly cause out of memory errors :) -- @JeremyRubin On Mon, Jan 2, 2017 at 4:39 PM, Steve Davis via bitcoin-dev < bitcoin-dev@lists.linuxfoundation.org> wrote: > Hi all, > > Suppose someone were to use the following pk_script: > > [op_2dup, op_2dup, op_2dup, op_2dup, op_2dup, ...(to limit)..., > op_2dup, op_hash160, , op_equalverify, op_checksig] > > This still seems to be valid AFAICS, and may be a potential attack vector= ? > > Thanks. > > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > > --001a1145a8369584950545284149 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I= t is an unfortunate script, but can't actually=C2=A0
=E2=80=8Bdo
=C2=A0that much
=E2=80=8B it seems=E2=80=8B
. The MAX_SCR= IPT_ELEMENT_SIZE =3D 520 Bytes.
=E2=80=8B Thus, it would seem the worst you could do with this wou= ld be to=C2=A0(10000-520*2)*520*2 bytes =C2=A0~=3D~ 10 MB.

=E2=80=8BM= uch more concerning would be the op_dup/op_cat style bug, which under a sim= ilar script =E2=80=8Bwould certainly cause out of memory errors :)


<= br clear=3D"all">

On Mon, Jan 2, 2017 at 4:39 PM, Steve Davis = via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org= > wrote:
Hi all,

Suppose someone were to use the following pk= _script:

= [op_2dup, op_2dup, op_2dup, op_2dup, op_2dup, ...(to limit)..., op_2dup,=C2= =A0op_hash160, <addr_hash>, op_equalverify, op_checksig]

This still seems to be valid AFAICS, and may be a = potential attack vector?

Thanks.
=


_____________________________________________= __
bitcoin-dev mailing list
bitcoin-dev@lists.= linuxfoundation.org
https://lists.linuxfoundation.org= /mailman/listinfo/bitcoin-dev


--001a1145a8369584950545284149--