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Dmitry Kasatkin8607c502011-10-05 11:54:46 +03001/*
2 * Copyright (C) 2011 Intel Corporation
3 *
4 * Author:
5 * Dmitry Kasatkin <dmitry.kasatkin@intel.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, version 2 of the License.
10 *
11 */
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/err.h>
Mimi Zohar7d2ce232013-08-13 08:47:43 -040016#include <linux/sched.h>
Dmitry Kasatkin65d543b2014-11-05 17:01:13 +020017#include <linux/slab.h>
Mimi Zohar7d2ce232013-08-13 08:47:43 -040018#include <linux/cred.h>
Dmitry Kasatkin8607c502011-10-05 11:54:46 +030019#include <linux/key-type.h>
20#include <linux/digsig.h>
Randy Dunlap120f3b12018-02-12 17:26:20 -080021#include <linux/vmalloc.h>
David Howellsa511e1a2016-04-06 16:14:26 +010022#include <crypto/public_key.h>
23#include <keys/system_keyring.h>
Dmitry Kasatkin8607c502011-10-05 11:54:46 +030024
25#include "integrity.h"
26
27static struct key *keyring[INTEGRITY_KEYRING_MAX];
28
Eric Biggersb2724d52018-09-07 13:22:23 -070029static const char * const keyring_name[INTEGRITY_KEYRING_MAX] = {
Dmitry Kasatkinf4dc3772015-10-22 21:26:10 +030030#ifndef CONFIG_INTEGRITY_TRUSTED_KEYRING
Dmitry Kasatkin8607c502011-10-05 11:54:46 +030031 "_evm",
Dmitry Kasatkin8607c502011-10-05 11:54:46 +030032 "_ima",
Mimi Zohar7d2ce232013-08-13 08:47:43 -040033#else
Dmitry Kasatkinf4dc3772015-10-22 21:26:10 +030034 ".evm",
Mimi Zohar7d2ce232013-08-13 08:47:43 -040035 ".ima",
36#endif
Nayna Jain9dc92c42018-12-09 01:56:59 +053037 ".platform",
Dmitry Kasatkin8607c502011-10-05 11:54:46 +030038};
39
David Howells56104cf2016-04-07 09:45:23 +010040#ifdef CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
41#define restrict_link_to_ima restrict_link_by_builtin_and_secondary_trusted
David Howellsa511e1a2016-04-06 16:14:26 +010042#else
David Howells56104cf2016-04-07 09:45:23 +010043#define restrict_link_to_ima restrict_link_by_builtin_trusted
David Howellsa511e1a2016-04-06 16:14:26 +010044#endif
45
Dmitry Kasatkin8607c502011-10-05 11:54:46 +030046int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
Dmitry Kasatkin089bc8e2013-10-10 15:56:13 +090047 const char *digest, int digestlen)
Dmitry Kasatkin8607c502011-10-05 11:54:46 +030048{
Seth Forsheeb4bfec72016-08-01 08:19:10 -050049 if (id >= INTEGRITY_KEYRING_MAX || siglen < 2)
Dmitry Kasatkin8607c502011-10-05 11:54:46 +030050 return -EINVAL;
51
52 if (!keyring[id]) {
53 keyring[id] =
Linus Torvalds34ef7bd2013-11-23 16:36:35 -080054 request_key(&key_type_keyring, keyring_name[id], NULL);
Dmitry Kasatkin8607c502011-10-05 11:54:46 +030055 if (IS_ERR(keyring[id])) {
56 int err = PTR_ERR(keyring[id]);
57 pr_err("no %s keyring: %d\n", keyring_name[id], err);
58 keyring[id] = NULL;
59 return err;
60 }
61 }
62
Dmitry Kasatkinb1aaab22013-10-10 16:12:03 +090063 switch (sig[1]) {
Dmitry Kasatkine0751252013-02-07 00:12:08 +020064 case 1:
Dmitry Kasatkinb1aaab22013-10-10 16:12:03 +090065 /* v1 API expect signature without xattr type */
66 return digsig_verify(keyring[id], sig + 1, siglen - 1,
Dmitry Kasatkine0751252013-02-07 00:12:08 +020067 digest, digestlen);
68 case 2:
69 return asymmetric_verify(keyring[id], sig, siglen,
70 digest, digestlen);
71 }
72
73 return -EOPNOTSUPP;
Dmitry Kasatkin8607c502011-10-05 11:54:46 +030074}
Mimi Zohar7d2ce232013-08-13 08:47:43 -040075
Nayna Jain9dc92c42018-12-09 01:56:59 +053076static int __integrity_init_keyring(const unsigned int id, key_perm_t perm,
77 struct key_restriction *restriction)
Mimi Zohar7d2ce232013-08-13 08:47:43 -040078{
79 const struct cred *cred = current_cred();
80 int err = 0;
81
Nayna Jain9dc92c42018-12-09 01:56:59 +053082 keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0),
83 KGIDT_INIT(0), cred, perm,
Nayna Jain60740ac2018-12-09 01:57:00 +053084 KEY_ALLOC_NOT_IN_QUOTA, restriction, NULL);
Nayna Jain9dc92c42018-12-09 01:56:59 +053085 if (IS_ERR(keyring[id])) {
86 err = PTR_ERR(keyring[id]);
87 pr_info("Can't allocate %s keyring (%d)\n",
88 keyring_name[id], err);
89 keyring[id] = NULL;
90 }
91
92 return err;
93}
94
95int __init integrity_init_keyring(const unsigned int id)
96{
97 struct key_restriction *restriction;
98 key_perm_t perm;
99
100 perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW
101 | KEY_USR_READ | KEY_USR_SEARCH;
102
103 if (id == INTEGRITY_KEYRING_PLATFORM) {
104 restriction = NULL;
105 goto out;
106 }
107
Eric Biggers2ab5daf2018-10-03 17:15:44 -0700108 if (!IS_ENABLED(CONFIG_INTEGRITY_TRUSTED_KEYRING))
Dmitry Kasatkinf4dc3772015-10-22 21:26:10 +0300109 return 0;
110
Mat Martineau2b6aa412016-08-31 16:05:43 -0700111 restriction = kzalloc(sizeof(struct key_restriction), GFP_KERNEL);
112 if (!restriction)
113 return -ENOMEM;
114
115 restriction->check = restrict_link_to_ima;
Nayna Jain9dc92c42018-12-09 01:56:59 +0530116 perm |= KEY_USR_WRITE;
Mat Martineau2b6aa412016-08-31 16:05:43 -0700117
Nayna Jain9dc92c42018-12-09 01:56:59 +0530118out:
119 return __integrity_init_keyring(id, perm, restriction);
Mimi Zohar7d2ce232013-08-13 08:47:43 -0400120}
Dmitry Kasatkin65d543b2014-11-05 17:01:13 +0200121
Nayna Jain60740ac2018-12-09 01:57:00 +0530122int __init integrity_add_key(const unsigned int id, const void *data,
123 off_t size, key_perm_t perm)
Dmitry Kasatkin65d543b2014-11-05 17:01:13 +0200124{
125 key_ref_t key;
Nayna Jain60740ac2018-12-09 01:57:00 +0530126 int rc = 0;
Dmitry Kasatkin65d543b2014-11-05 17:01:13 +0200127
128 if (!keyring[id])
129 return -EINVAL;
130
Nayna Jain60740ac2018-12-09 01:57:00 +0530131 key = key_create_or_update(make_key_ref(keyring[id], 1), "asymmetric",
132 NULL, data, size, perm,
133 KEY_ALLOC_NOT_IN_QUOTA);
134 if (IS_ERR(key)) {
135 rc = PTR_ERR(key);
136 pr_err("Problem loading X.509 certificate %d\n", rc);
137 } else {
138 pr_notice("Loaded X.509 cert '%s'\n",
139 key_ref_to_ptr(key)->description);
140 key_ref_put(key);
141 }
142
143 return rc;
144
145}
146
147int __init integrity_load_x509(const unsigned int id, const char *path)
148{
149 void *data;
150 loff_t size;
151 int rc;
152 key_perm_t perm;
153
Christoph Hellwiga7d3d032017-09-10 09:49:45 +0200154 rc = kernel_read_file_from_path(path, &data, &size, 0,
155 READING_X509_CERTIFICATE);
156 if (rc < 0) {
157 pr_err("Unable to open file: %s (%d)", path, rc);
Dmitry Kasatkin65d543b2014-11-05 17:01:13 +0200158 return rc;
Christoph Hellwiga7d3d032017-09-10 09:49:45 +0200159 }
Dmitry Kasatkin65d543b2014-11-05 17:01:13 +0200160
Nayna Jain60740ac2018-12-09 01:57:00 +0530161 perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ;
162
163 pr_info("Loading X.509 certificate: %s\n", path);
164 rc = integrity_add_key(id, (const void *)data, size, perm);
165
Christoph Hellwiga7d3d032017-09-10 09:49:45 +0200166 vfree(data);
Nayna Jain60740ac2018-12-09 01:57:00 +0530167 return rc;
168}
169
170int __init integrity_load_cert(const unsigned int id, const char *source,
171 const void *data, size_t len, key_perm_t perm)
172{
173 if (!data)
174 return -EINVAL;
175
176 pr_info("Loading X.509 certificate: %s\n", source);
177 return integrity_add_key(id, data, len, perm);
Dmitry Kasatkin65d543b2014-11-05 17:01:13 +0200178}