From patchwork Mon Nov 29 17:00:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mimi Zohar X-Patchwork-Id: 12645353 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 026E5C4167D for ; Mon, 29 Nov 2021 17:03:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346849AbhK2RGx (ORCPT ); Mon, 29 Nov 2021 12:06:53 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:29618 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232862AbhK2REw (ORCPT ); Mon, 29 Nov 2021 12:04:52 -0500 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 1ATGqTQb029443; Mon, 29 Nov 2021 17:01:33 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=VV7NbaGSBU5mx87Gn3b0nCfbWWPterfXx56KmUlJans=; b=IKbpPkdQ0bv0a16qPlz5cPzff3G6Mj+AgwiDgVtDKC5R1WKi9qX3QyVSW8AttmbxMaDn ICNxuxQ20fHXmp3HJgcXWMpgyeUbA79ZZi8/idHrUc5hqDplfMyfHgtS5wPGnMhKiAnb LcmEJ09yGzHVkxRwmyYAMCqBMqRQF+iwEGRRwqrU4noKyjTyE9D6Ip9szIDJ9TsmYU1H qL7Kxvp3klHmu5Lfu7i3/Kr9E7/JPGWSp7MAJC4vV4Y351U6br9A1rA1DA3k+lnczztW 8ilYFMHio94Bwoiud03Q7VgnZ32bbLx6HJdxVpax4+aNCPjunmv9B5X+em2GHVFSMPRR qA== Received: from ppma02fra.de.ibm.com (47.49.7a9f.ip4.static.sl-reverse.com [159.122.73.71]) by mx0a-001b2d01.pphosted.com with ESMTP id 3cn2s2r5t0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Nov 2021 17:01:33 +0000 Received: from pps.filterd (ppma02fra.de.ibm.com [127.0.0.1]) by ppma02fra.de.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 1ATGwdHW011359; Mon, 29 Nov 2021 17:01:24 GMT Received: from b06avi18626390.portsmouth.uk.ibm.com (b06avi18626390.portsmouth.uk.ibm.com [9.149.26.192]) by ppma02fra.de.ibm.com with ESMTP id 3ckca9p3et-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Nov 2021 17:01:23 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06avi18626390.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 1ATGrvEd52888002 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 29 Nov 2021 16:53:57 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BF5A04C062; Mon, 29 Nov 2021 17:01:19 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 00FBE4C05E; Mon, 29 Nov 2021 17:01:19 +0000 (GMT) Received: from li-f45666cc-3089-11b2-a85c-c57d1a57929f.ibm.com.com (unknown [9.65.68.145]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 29 Nov 2021 17:01:18 +0000 (GMT) From: Mimi Zohar To: linux-integrity@vger.kernel.org Cc: linux-fscrypt@vger.kernel.org, linux-kernel@vger.kernel.org, Mimi Zohar , Eric Biggers Subject: [PATCH 1/4] fs-verity: define a function to return the integrity protected file digest Date: Mon, 29 Nov 2021 12:00:54 -0500 Message-Id: <20211129170057.243127-2-zohar@linux.ibm.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20211129170057.243127-1-zohar@linux.ibm.com> References: <20211129170057.243127-1-zohar@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: 5hcNeUWbFf9Anjm00HrPU44rlvpBCaBN X-Proofpoint-GUID: 5hcNeUWbFf9Anjm00HrPU44rlvpBCaBN X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.0.607.475 definitions=2021-11-29_10,2021-11-28_01,2020-04-07_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 mlxlogscore=999 malwarescore=0 suspectscore=0 lowpriorityscore=0 phishscore=0 priorityscore=1501 bulkscore=0 clxscore=1015 spamscore=0 impostorscore=0 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000 definitions=main-2111290081 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org Define a function named fsverity_measure() to return the verity file digest and the associated hash algorithm (enum hash_algo). Signed-off-by: Mimi Zohar Reported-by: kernel test robot Reported-by: kernel test robot --- fs/verity/fsverity_private.h | 6 ----- fs/verity/measure.c | 49 ++++++++++++++++++++++++++++++++++++ include/linux/fsverity.h | 17 +++++++++++++ 3 files changed, 66 insertions(+), 6 deletions(-) diff --git a/fs/verity/fsverity_private.h b/fs/verity/fsverity_private.h index a7920434bae5..54c5f0993541 100644 --- a/fs/verity/fsverity_private.h +++ b/fs/verity/fsverity_private.h @@ -26,12 +26,6 @@ struct ahash_request; */ #define FS_VERITY_MAX_LEVELS 8 -/* - * Largest digest size among all hash algorithms supported by fs-verity. - * Currently assumed to be <= size of fsverity_descriptor::root_hash. - */ -#define FS_VERITY_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE - /* A hash algorithm supported by fs-verity */ struct fsverity_hash_alg { struct crypto_ahash *tfm; /* hash tfm, allocated on demand */ diff --git a/fs/verity/measure.c b/fs/verity/measure.c index f0d7b30c62db..98d8f6f2a2be 100644 --- a/fs/verity/measure.c +++ b/fs/verity/measure.c @@ -57,3 +57,52 @@ int fsverity_ioctl_measure(struct file *filp, void __user *_uarg) return 0; } EXPORT_SYMBOL_GPL(fsverity_ioctl_measure); + +/** + * fsverity_measure() - get a verity file's digest + * @inode: inode to get digest of + * @digest: pointer to the digest + * @alg: pointer to the hash algorithm enumeration + * + * Return the file hash algorithm, digest size, and digest of an fsverity + * protected file. + * + * Return: 0 on success, -errno on failure + */ +int fsverity_measure(struct inode *inode, u8 digest[FS_VERITY_MAX_DIGEST_SIZE], + enum hash_algo *alg) +{ + const struct fsverity_info *vi; + const struct fsverity_hash_alg *hash_alg; + int i; + + vi = fsverity_get_info(inode); + if (!vi) + return -ENODATA; /* not a verity file */ + + hash_alg = vi->tree_params.hash_alg; + memset(digest, 0, FS_VERITY_MAX_DIGEST_SIZE); + *alg = HASH_ALGO__LAST; + + /* convert hash algorithm to hash_algo_name */ + for (i = 0; i < HASH_ALGO__LAST; i++) { + pr_debug("name %s hash_algo_name[%d] %s\n", + hash_alg->name, i, hash_algo_name[i]); + + if (!strcmp(hash_alg->name, hash_algo_name[i])) { + *alg = i; + break; + } + } + + /* Shouldn't happen */ + if (*alg == HASH_ALGO__LAST) + return -EINVAL; + + memcpy(digest, vi->file_digest, hash_alg->digest_size); + + pr_debug("file digest:%s %*phN\n", hash_algo_name[*alg], + hash_digest_size[*alg], digest); + + return 0; +} diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h index b568b3c7d095..11006b60713b 100644 --- a/include/linux/fsverity.h +++ b/include/linux/fsverity.h @@ -12,8 +12,16 @@ #define _LINUX_FSVERITY_H #include +#include +#include #include +/* + * Largest digest size among all hash algorithms supported by fs-verity. + * Currently assumed to be <= size of fsverity_descriptor::root_hash. + */ +#define FS_VERITY_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE + /* Verity operations for filesystems */ struct fsverity_operations { @@ -131,6 +139,8 @@ int fsverity_ioctl_enable(struct file *filp, const void __user *arg); /* measure.c */ int fsverity_ioctl_measure(struct file *filp, void __user *arg); +int fsverity_measure(struct inode *inode, u8 digest[FS_VERITY_MAX_DIGEST_SIZE], + enum hash_algo *alg); /* open.c */ @@ -170,6 +180,13 @@ static inline int fsverity_ioctl_measure(struct file *filp, void __user *arg) return -EOPNOTSUPP; } +static inline int fsverity_measure(struct inode *inode, + u8 digest[FS_VERITY_MAX_DIGEST_SIZE], + enum hash_algo *alg) +{ + return -EOPNOTSUPP; +} + /* open.c */ static inline int fsverity_file_open(struct inode *inode, struct file *filp)