From patchwork Tue Aug 1 10:17:09 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 9874075 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 4D9FB6037D for ; Tue, 1 Aug 2017 10:18:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 26DA928602 for ; Tue, 1 Aug 2017 10:18:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1B79728683; Tue, 1 Aug 2017 10:18:17 +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=-4.4 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, SUSPICIOUS_RECIPS autolearn=unavailable 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 94CD728602 for ; Tue, 1 Aug 2017 10:18:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751779AbdHAKSP (ORCPT ); Tue, 1 Aug 2017 06:18:15 -0400 Received: from lhrrgout.huawei.com ([194.213.3.17]:32472 "EHLO lhrrgout.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751591AbdHAKSN (ORCPT ); Tue, 1 Aug 2017 06:18:13 -0400 Received: from 172.18.7.190 (EHLO lhreml708-cah.china.huawei.com) ([172.18.7.190]) by lhrrg02-dlp.huawei.com (MOS 4.3.7-GA FastPath queued) with ESMTP id DLS14764; Tue, 01 Aug 2017 10:18:10 +0000 (GMT) Received: from roberto-HP-EliteDesk-800-G2-DM-65W.huawei.com (10.204.65.245) by smtpsuk.huawei.com (10.201.108.49) with Microsoft SMTP Server (TLS) id 14.3.301.0; Tue, 1 Aug 2017 11:18:02 +0100 From: Roberto Sassu To: CC: , , , , Roberto Sassu Subject: [PATCH, RESEND 06/12] ima: added parser of digest lists metadata Date: Tue, 1 Aug 2017 12:17:09 +0200 Message-ID: <20170801101709.15046-1-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170725154423.24845-7-roberto.sassu@huawei.com> References: <20170725154423.24845-7-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.65.245] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020204.59805563.0051, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 3c87245a3cbb870a9c4d54da9bd6a854 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Userspace applications will be able to load digest lists by supplying their metadata. Digest list metadata are: - DATA_ALGO: algorithm of the digests to be uploaded - DATA_DIGEST: digest of the file containing the digest list - DATA_SIGNATURE: signature of the file containing the digest list - DATA_FILE_PATH: pathname - DATA_REF_ID: reference ID of the digest list - DATA_TYPE: type of digest list The new function ima_parse_digest_list_metadata() parses the metadata and load each file individually. Then, it parses the data according to the data type specified. Since digest lists are measured, their digest is added to the hash table so that IMA does not create a measurement entry for them (which would affect the performance). The only measurement entry created will be for the metadata. Signed-off-by: Roberto Sassu --- include/linux/fs.h | 1 + security/integrity/ima/Kconfig | 11 ++++ security/integrity/ima/Makefile | 1 + security/integrity/ima/ima.h | 8 +++ security/integrity/ima/ima_digest_list.c | 105 +++++++++++++++++++++++++++++++ 5 files changed, 126 insertions(+) create mode 100644 security/integrity/ima/ima_digest_list.c diff --git a/include/linux/fs.h b/include/linux/fs.h index 6e1fd5d..2eb6e7c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2751,6 +2751,7 @@ extern int do_pipe_flags(int *, int); id(KEXEC_IMAGE, kexec-image) \ id(KEXEC_INITRAMFS, kexec-initramfs) \ id(POLICY, security-policy) \ + id(DIGEST_LIST, security-digest-list) \ id(MAX_ID, ) #define __fid_enumify(ENUM, dummy) READING_ ## ENUM, diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index 35ef693..8965dcc 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -227,3 +227,14 @@ config IMA_APPRAISE_SIGNED_INIT default n help This option requires user-space init to be signed. + +config IMA_DIGEST_LIST + bool "Measure files depending on uploaded digest lists" + depends on IMA + default n + help + This option allows users to load digest lists. If a measured + file has the same digest of one from loaded lists, IMA will + not create a new measurement entry. A measurement entry will + be created only when digest lists are loaded (this entry + contains the digest of digest lists metadata). diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile index 29f198b..00dbe3a 100644 --- a/security/integrity/ima/Makefile +++ b/security/integrity/ima/Makefile @@ -9,4 +9,5 @@ ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \ ima_policy.o ima_template.o ima_template_lib.o ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o +ima-$(CONFIG_IMA_DIGEST_LIST) += ima_digest_list.o obj-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index a0c6808..9ecb7cc 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -157,6 +157,14 @@ int ima_restore_measurement_entry(struct ima_template_entry *entry); int ima_restore_measurement_list(loff_t bufsize, void *buf); struct ima_digest *ima_lookup_loaded_digest(u8 *digest); int ima_add_digest_data_entry(u8 *digest); +#ifdef CONFIG_IMA_DIGEST_LIST +ssize_t ima_parse_digest_list_metadata(loff_t size, void *buf); +#else +static inline ssize_t ima_parse_digest_list_metadata(loff_t size, void *buf) +{ + return -ENOTSUPP; +} +#endif int ima_measurements_show(struct seq_file *m, void *v); unsigned long ima_get_binary_runtime_size(void); int ima_init_template(void); diff --git a/security/integrity/ima/ima_digest_list.c b/security/integrity/ima/ima_digest_list.c new file mode 100644 index 0000000..3e1ff69b --- /dev/null +++ b/security/integrity/ima/ima_digest_list.c @@ -0,0 +1,105 @@ +/* + * Copyright (C) 2017 Huawei Technologies Co. Ltd. + * + * Author: Roberto Sassu + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, version 2 of the + * License. + * + * File: ima_digest_list.c + * Functions to manage digest lists. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include + +#include "ima.h" +#include "ima_template_lib.h" + +enum digest_metadata_fields {DATA_ALGO, DATA_DIGEST, DATA_SIGNATURE, + DATA_FILE_PATH, DATA_REF_ID, DATA_TYPE, + DATA__LAST}; + +static int ima_parse_digest_list_data(struct ima_field_data *data) +{ + void *digest_list; + loff_t digest_list_size; + u16 data_algo = le16_to_cpu(*(u16 *)data[DATA_ALGO].data); + u16 data_type = le16_to_cpu(*(u16 *)data[DATA_TYPE].data); + int ret; + + if (data_algo != ima_hash_algo) { + pr_err("Incompatible digest algorithm, expected %s\n", + hash_algo_name[ima_hash_algo]); + return -EINVAL; + } + + ret = kernel_read_file_from_path(data[DATA_FILE_PATH].data, + &digest_list, &digest_list_size, + 0, READING_DIGEST_LIST); + if (ret < 0) { + pr_err("Unable to open file: %s (%d)", + data[DATA_FILE_PATH].data, ret); + return ret; + } + + switch (data_type) { + default: + pr_err("Parser for data type %d not implemented\n", data_type); + ret = -EINVAL; + } + + if (ret < 0) { + pr_err("Error parsing file: %s (%d)\n", + data[DATA_FILE_PATH].data, ret); + return ret; + } + + vfree(digest_list); + return ret; +} + +ssize_t ima_parse_digest_list_metadata(loff_t size, void *buf) +{ + struct ima_field_data entry; + + struct ima_field_data entry_data[DATA__LAST] = { + [DATA_ALGO] = {.len = sizeof(u16)}, + [DATA_TYPE] = {.len = sizeof(u16)}, + }; + + DECLARE_BITMAP(data_mask, DATA__LAST); + void *bufp = buf, *bufendp = buf + size; + int ret; + + bitmap_zero(data_mask, DATA__LAST); + bitmap_set(data_mask, DATA_ALGO, 1); + bitmap_set(data_mask, DATA_TYPE, 1); + + ret = ima_parse_buf(bufp, bufendp, &bufp, 1, &entry, NULL, NULL, + ENFORCE_FIELDS, "metadata list entry"); + if (ret < 0) + return ret; + + ret = ima_parse_buf(entry.data, entry.data + entry.len, NULL, + DATA__LAST, entry_data, NULL, data_mask, + ENFORCE_FIELDS | ENFORCE_BUFEND, + "metadata entry data"); + if (ret < 0) + goto out; + + ret = ima_add_digest_data_entry(entry_data[DATA_DIGEST].data); + if (ret < 0) { + if (ret == -EEXIST) + ret = 0; + + goto out; + } + + ret = ima_parse_digest_list_data(entry_data); +out: + return ret < 0 ? ret : bufp - buf; +}