1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011 Intel Corporation
*
* Author:
* Dmitry Kasatkin <dmitry.kasatkin@intel.com>
*/
#include <linux/err.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/cred.h>
#include <linux/kernel_read_file.h>
#include <linux/key-type.h>
#include <linux/digsig.h>
#include <linux/vmalloc.h>
#include <crypto/public_key.h>
#include <keys/system_keyring.h>
#include "integrity.h"
static struct key *keyring[INTEGRITY_KEYRING_MAX];
static const char * const keyring_name[INTEGRITY_KEYRING_MAX] = {
#ifndef CONFIG_INTEGRITY_TRUSTED_KEYRING
"_evm",
"_ima",
#else
".evm",
".ima",
#endif
".platform",
};
#ifdef CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
#define restrict_link_to_ima restrict_link_by_builtin_and_secondary_trusted
#else
#define restrict_link_to_ima restrict_link_by_builtin_trusted
#endif
static struct key *integrity_keyring_from_id(const unsigned int id)
{
if (id >= INTEGRITY_KEYRING_MAX)
return ERR_PTR(-EINVAL);
if (!keyring[id]) {
keyring[id] =
request_key(&key_type_keyring, keyring_name[id], NULL);
if (IS_ERR(keyring[id])) {
int err = PTR_ERR(keyring[id]);
pr_err("no %s keyring: %d\n", keyring_name[id], err);
keyring[id] = NULL;
return ERR_PTR(err);
}
}
return keyring[id];
}
int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
const char *digest, int digestlen)
{
struct key *keyring;
if (siglen < 2)
return -EINVAL;
keyring = integrity_keyring_from_id(id);
if (IS_ERR(keyring))
return PTR_ERR(keyring);
switch (sig[1]) {
case 1:
/* v1 API expect signature without xattr type */
return digsig_verify(keyring, sig + 1, siglen - 1, digest,
digestlen);
case 2:
return asymmetric_verify(keyring, sig, siglen, digest,
digestlen);
}
return -EOPNOTSUPP;
}
int integrity_modsig_verify(const unsigned int id, const struct modsig *modsig)
{
struct key *keyring;
keyring = integrity_keyring_from_id(id);
if (IS_ERR(keyring))
return PTR_ERR(keyring);
return ima_modsig_verify(keyring, modsig);
}
static int __init __integrity_init_keyring(const unsigned int id,
key_perm_t perm,
struct key_restriction *restriction)
{
const struct cred *cred = current_cred();
int err = 0;
keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0),
KGIDT_INIT(0), cred, perm,
KEY_ALLOC_NOT_IN_QUOTA, restriction, NULL);
if (IS_ERR(keyring[id])) {
err = PTR_ERR(keyring[id]);
pr_info("Can't allocate %s keyring (%d)\n",
keyring_name[id], err);
keyring[id] = NULL;
} else {
if (id == INTEGRITY_KEYRING_PLATFORM)
set_platform_trusted_keys(keyring[id]);
}
return err;
}
int __init integrity_init_keyring(const unsigned int id)
{
struct key_restriction *restriction;
key_perm_t perm;
perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW
| KEY_USR_READ | KEY_USR_SEARCH;
if (id == INTEGRITY_KEYRING_PLATFORM) {
restriction = NULL;
goto out;
}
if (!IS_ENABLED(CONFIG_INTEGRITY_TRUSTED_KEYRING))
return 0;
restriction = kzalloc(sizeof(struct key_restriction), GFP_KERNEL);
if (!restriction)
return -ENOMEM;
restriction->check = restrict_link_to_ima;
perm |= KEY_USR_WRITE;
out:
return __integrity_init_keyring(id, perm, restriction);
}
int __init integrity_add_key(const unsigned int id, const void *data,
off_t size, key_perm_t perm)
{
key_ref_t key;
int rc = 0;
if (!keyring[id])
return -EINVAL;
key = key_create_or_update(make_key_ref(keyring[id], 1), "asymmetric",
NULL, data, size, perm,
KEY_ALLOC_NOT_IN_QUOTA);
if (IS_ERR(key)) {
rc = PTR_ERR(key);
pr_err("Problem loading X.509 certificate %d\n", rc);
} else {
pr_notice("Loaded X.509 cert '%s'\n",
key_ref_to_ptr(key)->description);
key_ref_put(key);
}
return rc;
}
int __init integrity_load_x509(const unsigned int id, const char *path)
{
void *data = NULL;
size_t size;
int rc;
key_perm_t perm;
rc = kernel_read_file_from_path(path, 0, &data, INT_MAX, NULL,
READING_X509_CERTIFICATE);
if (rc < 0) {
pr_err("Unable to open file: %s (%d)", path, rc);
return rc;
}
size = rc;
perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ;
pr_info("Loading X.509 certificate: %s\n", path);
rc = integrity_add_key(id, (const void *)data, size, perm);
vfree(data);
return rc;
}
int __init integrity_load_cert(const unsigned int id, const char *source,
const void *data, size_t len, key_perm_t perm)
{
if (!data)
return -EINVAL;
pr_info("Loading X.509 certificate: %s\n", source);
return integrity_add_key(id, data, len, perm);
}
|
