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=-0.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 28167C04EB8 for ; Mon, 10 Dec 2018 16:32:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E99EC20821 for ; Mon, 10 Dec 2018 16:32:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E99EC20821 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-security-module-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726209AbeLJQch (ORCPT ); Mon, 10 Dec 2018 11:32:37 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:29682 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726324AbeLJQch (ORCPT ); Mon, 10 Dec 2018 11:32:37 -0500 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wBAGTZ0U017884 for ; Mon, 10 Dec 2018 11:32:35 -0500 Received: from e31.co.us.ibm.com (e31.co.us.ibm.com [32.97.110.149]) by mx0a-001b2d01.pphosted.com with ESMTP id 2p9sedg2q4-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 10 Dec 2018 11:32:35 -0500 Received: from localhost by e31.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 10 Dec 2018 16:32:30 -0000 Received: from b03ledav006.gho.boulder.ibm.com (b03ledav006.gho.boulder.ibm.com [9.17.130.237]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id wBAGWUJW29294684 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 10 Dec 2018 16:32:30 GMT Received: from b03ledav006.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E742AC605F; Mon, 10 Dec 2018 16:32:29 +0000 (GMT) Received: from b03ledav006.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 953C0C605D; Mon, 10 Dec 2018 16:32:29 +0000 (GMT) Received: from [9.2.202.70] (unknown [9.2.202.70]) by b03ledav006.gho.boulder.ibm.com (Postfix) with ESMTP; Mon, 10 Dec 2018 16:32:29 +0000 (GMT) Subject: Re: Documenting the proposal for TPM 2.0 security in the face of bus interposer attacks To: James Bottomley , linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org References: <1542648844.2910.9.camel@HansenPartnership.com> From: Ken Goldman Date: Mon, 10 Dec 2018 11:33:04 -0500 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.3.2 MIME-Version: 1.0 In-Reply-To: <1542648844.2910.9.camel@HansenPartnership.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 18121016-8235-0000-0000-00000E368167 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010208; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000270; SDB=6.01129798; UDB=6.00587025; IPR=6.00909932; MB=3.00024642; MTD=3.00000008; XFM=3.00000015; UTC=2018-12-10 16:32:32 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18121016-8236-0000-0000-000043A7A772 Message-Id: <16c8baf7-e2a9-6e12-b736-a0e2384282ed@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-12-10_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=945 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1812100148 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On 11/19/2018 12:34 PM, James Bottomley wrote: > 2. At some point in time the attacker could reset the TPM, clearing > the PCRs and then send down their own measurements which would > effectively overwrite the boot time measurements the TPM has > already done. > [snip] > However, the second can only really be detected by relying > on some sort of mechanism for protection which would change over TPM > reset. FYI: TPM 2.0 has a resetCount that can be used to detect, but not protect against, this attack. > Every TPM comes shipped with a couple of X.509 certificates for the > primary endorsement key. This document assumes that the Elliptic > Curve version of the certificate exists at 01C00002, but will work > equally well with the RSA certificate (at 01C00001). A nit. The RSA cert is at 01c00002. The ECC cert is at 01c0000a.