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9#include <linux/err.h>
10#include <linux/sched.h>
11#include <linux/slab.h>
12#include <linux/cred.h>
13#include <linux/kernel_read_file.h>
14#include <linux/key-type.h>
15#include <linux/digsig.h>
16#include <linux/vmalloc.h>
17#include <crypto/public_key.h>
18#include <keys/system_keyring.h>
19
20#include "integrity.h"
21
22static struct key *keyring[INTEGRITY_KEYRING_MAX];
23
24static const char * const keyring_name[INTEGRITY_KEYRING_MAX] = {
25#ifndef CONFIG_INTEGRITY_TRUSTED_KEYRING
26 "_evm",
27 "_ima",
28#else
29 ".evm",
30 ".ima",
31#endif
32 ".platform",
33 ".machine",
34};
35
36#ifdef CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
37#define restrict_link_to_ima restrict_link_by_builtin_and_secondary_trusted
38#else
39#define restrict_link_to_ima restrict_link_by_builtin_trusted
40#endif
41
42static struct key *integrity_keyring_from_id(const unsigned int id)
43{
44 if (id >= INTEGRITY_KEYRING_MAX)
45 return ERR_PTR(-EINVAL);
46
47 if (!keyring[id]) {
48 keyring[id] =
49 request_key(&key_type_keyring, keyring_name[id], NULL);
50 if (IS_ERR(keyring[id])) {
51 int err = PTR_ERR(keyring[id]);
52 pr_err("no %s keyring: %d\n", keyring_name[id], err);
53 keyring[id] = NULL;
54 return ERR_PTR(err);
55 }
56 }
57
58 return keyring[id];
59}
60
61int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
62 const char *digest, int digestlen)
63{
64 struct key *keyring;
65
66 if (siglen < 2)
67 return -EINVAL;
68
69 keyring = integrity_keyring_from_id(id);
70 if (IS_ERR(keyring))
71 return PTR_ERR(keyring);
72
73 switch (sig[1]) {
74 case 1:
75
76 return digsig_verify(keyring, sig + 1, siglen - 1, digest,
77 digestlen);
78 case 2:
79 case 3:
80 return asymmetric_verify(keyring, sig, siglen, digest,
81 digestlen);
82 }
83
84 return -EOPNOTSUPP;
85}
86
87int integrity_modsig_verify(const unsigned int id, const struct modsig *modsig)
88{
89 struct key *keyring;
90
91 keyring = integrity_keyring_from_id(id);
92 if (IS_ERR(keyring))
93 return PTR_ERR(keyring);
94
95 return ima_modsig_verify(keyring, modsig);
96}
97
98static int __init __integrity_init_keyring(const unsigned int id,
99 key_perm_t perm,
100 struct key_restriction *restriction)
101{
102 const struct cred *cred = current_cred();
103 int err = 0;
104
105 keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0),
106 KGIDT_INIT(0), cred, perm,
107 KEY_ALLOC_NOT_IN_QUOTA, restriction, NULL);
108 if (IS_ERR(keyring[id])) {
109 err = PTR_ERR(keyring[id]);
110 pr_info("Can't allocate %s keyring (%d)\n",
111 keyring_name[id], err);
112 keyring[id] = NULL;
113 } else {
114 if (id == INTEGRITY_KEYRING_PLATFORM)
115 set_platform_trusted_keys(keyring[id]);
116 if (id == INTEGRITY_KEYRING_MACHINE && trust_moklist())
117 set_machine_trusted_keys(keyring[id]);
118 if (id == INTEGRITY_KEYRING_IMA)
119 load_module_cert(keyring[id]);
120 }
121
122 return err;
123}
124
125int __init integrity_init_keyring(const unsigned int id)
126{
127 struct key_restriction *restriction;
128 key_perm_t perm;
129
130 perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW
131 | KEY_USR_READ | KEY_USR_SEARCH;
132
133 if (id == INTEGRITY_KEYRING_PLATFORM ||
134 id == INTEGRITY_KEYRING_MACHINE) {
135 restriction = NULL;
136 goto out;
137 }
138
139 if (!IS_ENABLED(CONFIG_INTEGRITY_TRUSTED_KEYRING))
140 return 0;
141
142 restriction = kzalloc(sizeof(struct key_restriction), GFP_KERNEL);
143 if (!restriction)
144 return -ENOMEM;
145
146 restriction->check = restrict_link_to_ima;
147
148
149
150
151
152
153 if (id != INTEGRITY_KEYRING_MACHINE)
154 perm |= KEY_USR_WRITE;
155
156out:
157 return __integrity_init_keyring(id, perm, restriction);
158}
159
160static int __init integrity_add_key(const unsigned int id, const void *data,
161 off_t size, key_perm_t perm)
162{
163 key_ref_t key;
164 int rc = 0;
165
166 if (!keyring[id])
167 return -EINVAL;
168
169 key = key_create_or_update(make_key_ref(keyring[id], 1), "asymmetric",
170 NULL, data, size, perm,
171 KEY_ALLOC_NOT_IN_QUOTA);
172 if (IS_ERR(key)) {
173 rc = PTR_ERR(key);
174 pr_err("Problem loading X.509 certificate %d\n", rc);
175 } else {
176 pr_notice("Loaded X.509 cert '%s'\n",
177 key_ref_to_ptr(key)->description);
178 key_ref_put(key);
179 }
180
181 return rc;
182
183}
184
185int __init integrity_load_x509(const unsigned int id, const char *path)
186{
187 void *data = NULL;
188 size_t size;
189 int rc;
190 key_perm_t perm;
191
192 rc = kernel_read_file_from_path(path, 0, &data, INT_MAX, NULL,
193 READING_X509_CERTIFICATE);
194 if (rc < 0) {
195 pr_err("Unable to open file: %s (%d)", path, rc);
196 return rc;
197 }
198 size = rc;
199
200 perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ;
201
202 pr_info("Loading X.509 certificate: %s\n", path);
203 rc = integrity_add_key(id, (const void *)data, size, perm);
204
205 vfree(data);
206 return rc;
207}
208
209int __init integrity_load_cert(const unsigned int id, const char *source,
210 const void *data, size_t len, key_perm_t perm)
211{
212 if (!data)
213 return -EINVAL;
214
215 pr_info("Loading X.509 certificate: %s\n", source);
216 return integrity_add_key(id, data, len, perm);
217}
218
