From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 38FB54A9BC; Wed, 20 Dec 2023 22:14:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="UX0vSB4S" Received: from pps.filterd (m0353725.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3BKLRUcY004658; Wed, 20 Dec 2023 22:13:52 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=Lme9PvKXLllsH+Mh5EhYOYKBv8+v9jzfCVw+p6oPtF8=; b=UX0vSB4SqHpjxVnbfc6C1k+QMHyj/FPDdaZHVuhBjySSqCl+CV0R8qcm+e/WU+l6Syg4 OBz4uR9gQkhjjnJI4ST4DaCVbNHbMvHX5epourH7DnBE81J8xOyXI6yXRfmic1cKsEyY csO3ENneNcjmroDhuzj/MVFlu9WnE+JeczAlCYPshnQ/iGJaqJYn/qFq8a9/JtDliflT xXf731CgorhxcCmJYxHcQs84zdS7311yPGeFZOZL9i32i08FhauoVG+mBqi7tqy4drjM ZvW4NHyDuGuR5V5vkQPFieqLWv0kz0Ib6BR3YDBAfQebq7BCHz++Iw2D928I7o+ZAonv ew== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3v42q73crh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 20 Dec 2023 22:13:52 +0000 Received: from m0353725.ppops.net (m0353725.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 3BKLbqu1021251; Wed, 20 Dec 2023 22:13:51 GMT Received: from ppma11.dal12v.mail.ibm.com (db.9e.1632.ip4.static.sl-reverse.com [50.22.158.219]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3v42q73cr9-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 20 Dec 2023 22:13:51 +0000 Received: from pps.filterd (ppma11.dal12v.mail.ibm.com [127.0.0.1]) by ppma11.dal12v.mail.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 3BKLNtYv012418; Wed, 20 Dec 2023 22:13:51 GMT Received: from smtprelay03.wdc07v.mail.ibm.com ([172.16.1.70]) by ppma11.dal12v.mail.ibm.com (PPS) with ESMTPS id 3v1rx20stm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 20 Dec 2023 22:13:50 +0000 Received: from smtpav01.wdc07v.mail.ibm.com (smtpav01.wdc07v.mail.ibm.com [10.39.53.228]) by smtprelay03.wdc07v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 3BKMDoNK22610544 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 20 Dec 2023 22:13:50 GMT Received: from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3474058055; Wed, 20 Dec 2023 22:13:50 +0000 (GMT) Received: from smtpav01.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 96D585804B; Wed, 20 Dec 2023 22:13:48 +0000 (GMT) Received: from [9.67.17.94] (unknown [9.67.17.94]) by smtpav01.wdc07v.mail.ibm.com (Postfix) with ESMTP; Wed, 20 Dec 2023 22:13:48 +0000 (GMT) Message-ID: <1c370ecf-272a-4052-8f06-4fcfd9bf08b5@linux.ibm.com> Date: Wed, 20 Dec 2023 17:13:47 -0500 Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC V2] IMA Log Snapshotting Design Proposal To: Paul Moore , Mimi Zohar Cc: Tushar Sugandhi , linux-integrity@vger.kernel.org, peterhuewe@gmx.de, Jarkko Sakkinen , jgg@ziepe.ca, bhe@redhat.com, vgoyal@redhat.com, Dave Young , "kexec@lists.infradead.org" , jmorris@namei.org, serge@hallyn.com, James Bottomley , linux-security-module@vger.kernel.org, Tyler Hicks , Lakshmi Ramasubramanian , Sush Shringarputale References: <6c0c32d5-e636-2a0e-5bdf-538c904ceea3@linux.microsoft.com> <8bff2bf1a4629aacec7b6311d77f233cb75b2f8a.camel@linux.ibm.com> <1b6853e8354af7033e6d87e77cfb175526753c38.camel@linux.ibm.com> Content-Language: en-US From: Ken Goldman In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: jdm9hFg47T3cry3by7vWsYkIffxDdom2 X-Proofpoint-ORIG-GUID: JoqsYci3m-cIbuNnF9sp5yvfTxOvXDiv X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-12-20_13,2023-12-20_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 lowpriorityscore=0 suspectscore=0 mlxlogscore=909 bulkscore=0 malwarescore=0 clxscore=1011 adultscore=0 mlxscore=0 priorityscore=1501 spamscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311290000 definitions=main-2312200158 I'm still struggling with the "new root of trust" concept. Something - a user space agent, a third party, etc. - has to retain the entire log from event 0, because a new verifier needs all measurements. Therefore, the snapshot aggregate seems redundant. It has to be verified to match the snapshotted events. A redundancy is an attack surface. A badly written verifier might not do that verification, and this permits snapshotted events to be forged. No aggregate means the verifier can't make a mistake. On 11/22/2023 9:22 AM, Paul Moore wrote: > I believe the intent is to only pause the measurements while the > snapshot_aggregate is generated, not for the duration of the entire > snapshot process. The purpose of the snapshot_aggregate is to > establish a new root of trust, similar to the boot_aggregate, to help > improve attestation performance.