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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 317F8ECDE46 for ; Thu, 25 Oct 2018 19:34:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E43FC20824 for ; Thu, 25 Oct 2018 19:34:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E43FC20824 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-integrity-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725867AbeJZEIo (ORCPT ); Fri, 26 Oct 2018 00:08:44 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:53168 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725784AbeJZEIo (ORCPT ); Fri, 26 Oct 2018 00:08:44 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w9PJK3m8096170 for ; Thu, 25 Oct 2018 15:34:38 -0400 Received: from e32.co.us.ibm.com (e32.co.us.ibm.com [32.97.110.150]) by mx0b-001b2d01.pphosted.com with ESMTP id 2nbkj99k57-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 25 Oct 2018 15:34:37 -0400 Received: from localhost by e32.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) Thu, 25 Oct 2018 13:34:34 -0600 Received: from b03ledav005.gho.boulder.ibm.com (b03ledav005.gho.boulder.ibm.com [9.17.130.236]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w9PJYXgn26673330 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 25 Oct 2018 19:34:33 GMT Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7D20FBE04F; Thu, 25 Oct 2018 19:34:33 +0000 (GMT) Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3074DBE054; Thu, 25 Oct 2018 19:34:31 +0000 (GMT) Received: from [9.2.202.77] (unknown [9.2.202.77]) by b03ledav005.gho.boulder.ibm.com (Postfix) with ESMTP; Thu, 25 Oct 2018 19:34:30 +0000 (GMT) Subject: Re: Proposed change to tpm driver tpm_pcr_extend To: Monty Wiseman , linux-integrity@vger.kernel.org, "David (GE Global Research, US)" References: From: Ken Goldman Date: Thu, 25 Oct 2018 15:34:40 -0400 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 x-cbid: 18102519-0004-0000-0000-000014A477E4 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009934; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000268; SDB=6.01107905; UDB=6.00573853; IPR=6.00887988; MB=3.00023909; MTD=3.00000008; XFM=3.00000015; UTC=2018-10-25 19:34:35 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18102519-0005-0000-0000-0000894858C0 Message-Id: <442debb9-e9bf-ad41-22cf-3de1b5f9db8a@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-10-25_10:,, 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=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1810250159 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On 10/24/2018 5:35 AM, Monty Wiseman wrote: > Option C: > This is a viable option and may actully be what the caller wants. There actually > is no rule the all banks must be extended. In fact when "sealing", the > caller lists Doesn't not extending a bank open the platform to attack? Even if one caller is sealing to one bank, other applications may use a different bank. If that bank was no extended, the caller could extend counterfeit measurements and subvert an application. IMHO, for PCRs that are doing software measurements, the rule should be that all allocated banks should be extended. > the pcr banks they want to seal to. (While is it technically possible > to provide the > TPM2_PolicyPCR a mix of banks I don't believe this practical as only > one expected hash > is provided as input. We should consider this option. I'm nearly sure that one can run TPM2_PolicyPCR with multiple banks. 1 - The input parameter pcrDigest is optional. It permits the caller to check for correct PCRs early in the policy process. For example, it could avoid an unnecessary digital signature or password prompt. That's why policies should be constructed with policypcr before terms that require external input. 2 - The spec Part 1 describes the pcrDigest calculation, and I don't see anything that mandates only one bank.