From patchwork Fri Feb 11 21:43:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mimi Zohar X-Patchwork-Id: 12743925 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D1F6DC433F5 for ; Fri, 11 Feb 2022 21:43:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353787AbiBKVn2 (ORCPT ); Fri, 11 Feb 2022 16:43:28 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:55298 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350658AbiBKVn1 (ORCPT ); Fri, 11 Feb 2022 16:43:27 -0500 Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BFD9AC62; Fri, 11 Feb 2022 13:43:25 -0800 (PST) Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 21BLUc67019629; Fri, 11 Feb 2022 21:43:23 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : content-transfer-encoding : mime-version; s=pp1; bh=lAPZZmqkcdFxs/5+7TVyE8qan2jmuvnoLt958gIaeZ4=; b=KhCP/OOwA+9qW0eKbNMptsSojN0TLutopKiV5eAcIB/ZGxnRIDU9xQllW4uGgLJysVhf bS+arq6JHw/qxpwJUpLRyFrmHY2i3miRRNv/j4cI3CZtvVUIOef/8vsbCEMus4fMagqT 5c+PrcjEc8nGRIyl10xDaFAzv6m9LdM6Wpq5dERPg46kWAdwiBLJylrkfah47GQrXlpk OA03kzrGRCwAiksN5oI5N/lbfJTO61JgkItVkOwlnYcFFHtLZ8OVllvIlw9bGdITXK/C 8Dve38D32aHOA6cNi6NZB3rxpWdElHIMaa2gJMjf6DsrGtmXz7VVzN74tfjPTrnM7VAf hw== Received: from ppma04fra.de.ibm.com (6a.4a.5195.ip4.static.sl-reverse.com [149.81.74.106]) by mx0b-001b2d01.pphosted.com with ESMTP id 3e50hjref2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 11 Feb 2022 21:43:22 +0000 Received: from pps.filterd (ppma04fra.de.ibm.com [127.0.0.1]) by ppma04fra.de.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 21BLYD5s008618; Fri, 11 Feb 2022 21:43:21 GMT Received: from b06cxnps3074.portsmouth.uk.ibm.com (d06relay09.portsmouth.uk.ibm.com [9.149.109.194]) by ppma04fra.de.ibm.com with ESMTP id 3e2ygr1hxb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 11 Feb 2022 21:43:21 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06cxnps3074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 21BLhHoD45940994 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 11 Feb 2022 21:43:17 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 30A0D52052; Fri, 11 Feb 2022 21:43:17 +0000 (GMT) Received: from li-f45666cc-3089-11b2-a85c-c57d1a57929f.ibm.com.com (unknown [9.65.69.128]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTP id 5E0785204E; Fri, 11 Feb 2022 21:43:16 +0000 (GMT) From: Mimi Zohar To: linux-integrity@vger.kernel.org Cc: Mimi Zohar , Eric Biggers , Stefan Berger , linux-fscrypt@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v5 0/8] ima: support fs-verity digests and signatures Date: Fri, 11 Feb 2022 16:43:02 -0500 Message-Id: <20220211214310.119257-1-zohar@linux.ibm.com> X-Mailer: git-send-email 2.27.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: LRZzjNPK9YY_yH5iBAwWKQMXFK3i8rH9 X-Proofpoint-ORIG-GUID: LRZzjNPK9YY_yH5iBAwWKQMXFK3i8rH9 X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.816,Hydra:6.0.425,FMLib:17.11.62.513 definitions=2022-02-11_05,2022-02-11_01,2021-12-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 bulkscore=0 priorityscore=1501 mlxscore=0 lowpriorityscore=0 adultscore=0 suspectscore=0 mlxlogscore=999 impostorscore=0 clxscore=1015 phishscore=0 malwarescore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2201110000 definitions=main-2202110108 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org Support for including fs-verity file digests and signatures in the IMA measurement list as well as verifying the fs-verity file digest based signatures, both based on IMA policy rules, was discussed prior to fs-verity being upstreamed[1,2]. Support for including fs-verity file digests in the 'd-ng' template field is based on a new policy rule option named 'digest_type=verity'. A new template field named 'd-type' as well as a new template named 'ima-ngv2' are defined to differentiate between the regular IMA file hashes from the fs-verity file digests (tree-hash based file hashes) stored in the 'd-ng' template field of the measurement list. A new signature version (v3) is defined as a hash of the 'ima_file_id' struct, to disambiguate the signatures stored as 'security.ima' xattr. The policy rule 'appraise_type=' option is extended to support 'sigv3', which is initially limited to fs-verity. The fs-verity 'appraise' rules are identified by the 'digest-type=verity' option and require the 'appraise_type=sigv3' option. Lastly, for IMA to differentiate between the original IMA signature from an fs-verity signature a new 'xattr_type' named IMA_VERITY_DIGSIG is defined. [1] https://events19.linuxfoundation.org/wp-content/uploads/2017/11/fs-verify_Mike-Halcrow_Eric-Biggers.pdf [2] Documentation/filesystems/fsverity.rst Changelog v5: - Define ima_max_digest_size struct, removing the locally defined versions. - Don't overload the 'digest_type=verity' to imply a verity signature, but extend the 'appraise_type' policy rule option to define 'sigv3'. Changelog v4: - Based on Eric Bigger's signature verification concerns of replacing the contents of a file with the ima_file_id struct hash, require per policy rule signature versions. - Addressed Eric Bigger's other comments. - Added new audit messages "causes". - Updated patch descriptions. Changelog v3: - Addressed Eric Bigger's comments: included Ack, incremented the signature format version, the crypto issues are generic and will be addressed by him separately. - Addressed Vitaly Chikunov's comments: hard coded maximum digest size rather than using a flexible array, removed unnecessary assignment, and fixed comment to match variable name. - Defined new "ima_max_digest_size" struct to avoid wrapping the "ima_digest_data" struct inside a function local structure or having to dynamically allocate it with enough memory for the specific hash algo size. Changelog v2: - Addressed Eric Bigger's comments: sign the hash of fsverity's digest and the digest's metadata, use match_string, use preferred function name fsverity_get_digest(), support including unsigned fs-verity's digests in the IMA measurement list. - Remove signatures requirement for including fs-verity's file digests in the 'd-ng' field of the measurement list. Changelog v1: - Updated both fsverity and IMA documentation. - Addressed both Eric Bigger's and Lakshmi's comments. Mimi Zohar (8): ima: rename IMA_ACTION_FLAGS to IMA_NONACTION_FLAGS ima: define ima_max_digest_data struct without a flexible array variable fs-verity: define a function to return the integrity protected file digest ima: define a new template field 'd-type' and a new template 'ima-ngv2' ima: permit fsverity's file digests in the IMA measurement list ima: define signature version 3 ima: support fs-verity file digest based version 3 signatures fsverity: update the documentation Documentation/ABI/testing/ima_policy | 30 +++++- Documentation/filesystems/fsverity.rst | 22 +++-- Documentation/security/IMA-templates.rst | 11 ++- fs/verity/Kconfig | 1 + fs/verity/fsverity_private.h | 7 -- fs/verity/measure.c | 41 ++++++++ include/linux/fsverity.h | 18 ++++ security/integrity/digsig.c | 3 +- security/integrity/ima/ima_api.c | 49 ++++++++-- security/integrity/ima/ima_appraise.c | 112 +++++++++++++++++++++- security/integrity/ima/ima_init.c | 5 +- security/integrity/ima/ima_main.c | 7 +- security/integrity/ima/ima_policy.c | 66 +++++++++++-- security/integrity/ima/ima_template.c | 3 + security/integrity/ima/ima_template_lib.c | 28 +++++- security/integrity/ima/ima_template_lib.h | 2 + security/integrity/integrity.h | 39 +++++++- 17 files changed, 388 insertions(+), 56 deletions(-)