From patchwork Wed Feb 28 17:55:21 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nayna X-Patchwork-Id: 10249151 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4C38660211 for ; Wed, 28 Feb 2018 17:57:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 33C5328C50 for ; Wed, 28 Feb 2018 17:57:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2802428C6D; Wed, 28 Feb 2018 17:57:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9543528C56 for ; Wed, 28 Feb 2018 17:57:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934701AbeB1R5M (ORCPT ); Wed, 28 Feb 2018 12:57:12 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:50384 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934699AbeB1R5I (ORCPT ); Wed, 28 Feb 2018 12:57:08 -0500 Received: from pps.filterd (m0098410.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w1SHsJHK100353 for ; Wed, 28 Feb 2018 12:57:08 -0500 Received: from e06smtp12.uk.ibm.com (e06smtp12.uk.ibm.com [195.75.94.108]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ge0rpsds8-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 28 Feb 2018 12:57:07 -0500 Received: from localhost by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 28 Feb 2018 17:57:02 -0000 Received: from d06av24.portsmouth.uk.ibm.com (d06av24.portsmouth.uk.ibm.com [9.149.105.60]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w1SHv2ru11993218; Wed, 28 Feb 2018 17:57:02 GMT Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DB79842045; Wed, 28 Feb 2018 17:49:31 +0000 (GMT) Received: from d06av24.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6BAC942049; Wed, 28 Feb 2018 17:49:29 +0000 (GMT) Received: from swastik.in.ibm.com (unknown [9.195.33.56]) by d06av24.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 28 Feb 2018 17:49:29 +0000 (GMT) From: Nayna Jain To: dhowells@redhat.com Cc: keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org, Nayna Jain Subject: [PATCH 3/3] ima: support platform keyring for kernel appraisal Date: Wed, 28 Feb 2018 23:25:21 +0530 X-Mailer: git-send-email 2.13.6 In-Reply-To: <20180228175521.10287-1-nayna@linux.vnet.ibm.com> References: <20180228175521.10287-1-nayna@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18022817-0008-0000-0000-000004D6177C X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18022817-0009-0000-0000-00001E69186A Message-Id: <20180228175521.10287-3-nayna@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2018-02-28_10:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1802280218 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Distros may sign the kernel images and, possibly, the initramfs with platform trusted keys. On secure boot enabled systems or embedded devices, these signatures are to be validated using keys on the platform keyring. This patch enables IMA-appraisal to access the platform keyring, based on a new Kconfig option "IMA_USE_PLATFORM_KEYRING". Signed-off-by: Nayna Jain --- security/integrity/digsig.c | 15 +++++++++++++++ security/integrity/ima/Kconfig | 10 ++++++++++ security/integrity/ima/ima_appraise.c | 22 +++++++++++++++++----- security/integrity/ima/ima_init.c | 4 ++++ security/integrity/integrity.h | 17 ++++++++++++++++- 5 files changed, 62 insertions(+), 6 deletions(-) diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c index 6f9e4ce568cd..87f2ae5ba48c 100644 --- a/security/integrity/digsig.c +++ b/security/integrity/digsig.c @@ -34,6 +34,8 @@ static const char *keyring_name[INTEGRITY_KEYRING_MAX] = { ".ima", #endif "_module", + ".platform_keys", + }; #ifdef CONFIG_INTEGRITY_TRUSTED_KEYRING @@ -78,6 +80,19 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, return -EOPNOTSUPP; } +#ifdef CONFIG_IMA_USE_PLATFORM_KEYRING +int __init integrity_load_keyring(const unsigned int id) +{ + + keyring[id] = find_keyring_by_name(keyring_name[id], 0); + if (IS_ERR(keyring[id])) + if (PTR_ERR(keyring[id]) != -ENOKEY) + return PTR_ERR(keyring[id]); + return 0; + +} +#endif + int __init integrity_init_keyring(const unsigned int id) { const struct cred *cred = current_cred(); diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index 35ef69312811..2e89d4f8a364 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -227,3 +227,13 @@ config IMA_APPRAISE_SIGNED_INIT default n help This option requires user-space init to be signed. + +config IMA_USE_PLATFORM_KEYRING + bool "IMA uses keys from Platform Keyring for verification" + depends on PLATFORM_KEYRING + depends on IMA_APPRAISE + depends on INTEGRITY_ASYMMETRIC_KEYS + default n + help + This option enables IMA appraisal to look for the platform + trusted keys in .platform_keys keyring. diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index f2803a40ff82..5fec29f40595 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -276,13 +276,25 @@ int ima_appraise_measurement(enum ima_hooks func, (const char *)xattr_value, rc, iint->ima_hash->digest, iint->ima_hash->length); - if (rc == -EOPNOTSUPP) { - status = INTEGRITY_UNKNOWN; - } else if (rc) { + if (rc) { + if (rc == -EOPNOTSUPP) { + status = INTEGRITY_UNKNOWN; + break; + } + if (func == KEXEC_KERNEL_CHECK) { + rc = integrity_digsig_verify( + INTEGRITY_KEYRING_PLATFORM, + (const char *)xattr_value, + xattr_len, + iint->ima_hash->digest, + iint->ima_hash->length); + if (!rc) { + status = INTEGRITY_PASS; + break; + } + } cause = "invalid-signature"; status = INTEGRITY_FAIL; - } else { - status = INTEGRITY_PASS; } break; default: diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index 29b72cd2502e..fda38b6c3ab3 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -122,6 +122,10 @@ int __init ima_init(void) if (rc) return rc; + rc = integrity_load_keyring(INTEGRITY_KEYRING_PLATFORM); + if (rc) + pr_info("Platform keyring is not found. (rc=%d)\n", rc); + rc = ima_init_crypto(); if (rc) return rc; diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 50a8e3365df7..d0aeb6a39036 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -136,13 +136,23 @@ int integrity_kernel_read(struct file *file, loff_t offset, #define INTEGRITY_KEYRING_EVM 0 #define INTEGRITY_KEYRING_IMA 1 #define INTEGRITY_KEYRING_MODULE 2 -#define INTEGRITY_KEYRING_MAX 3 +#define INTEGRITY_KEYRING_PLATFORM 3 +#define INTEGRITY_KEYRING_MAX 4 #ifdef CONFIG_INTEGRITY_SIGNATURE int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, const char *digest, int digestlen); +#ifdef CONFIG_IMA_USE_PLATFORM_KEYRING +int __init integrity_load_keyring(const unsigned int id); +#else +static inline int __init integrity_load_keyring(const unsigned int id) +{ + return 0; +} +#endif + int __init integrity_init_keyring(const unsigned int id); int __init integrity_load_x509(const unsigned int id, const char *path); #else @@ -154,6 +164,11 @@ static inline int integrity_digsig_verify(const unsigned int id, return -EOPNOTSUPP; } +static inline int __init integrity_load_keyring(const unsigned int id) +{ + return 0; +} + static inline int integrity_init_keyring(const unsigned int id) { return 0;