1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* System trusted keyring for trusted public keys
4 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
8 #include <linux/export.h>
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/cred.h>
12 #include <linux/err.h>
13 #include <linux/slab.h>
14 #include <linux/uidgid.h>
15 #include <linux/verification.h>
16 #include <keys/asymmetric-type.h>
17 #include <keys/system_keyring.h>
18 #include <crypto/pkcs7.h>
20 static struct key
*builtin_trusted_keys
;
21 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
22 static struct key
*secondary_trusted_keys
;
24 #ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
25 static struct key
*machine_trusted_keys
;
27 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
28 static struct key
*platform_trusted_keys
;
31 extern __initconst
const u8 system_certificate_list
[];
32 extern __initconst
const unsigned long system_certificate_list_size
;
33 extern __initconst
const unsigned long module_cert_size
;
36 * restrict_link_by_builtin_trusted - Restrict keyring addition by built-in CA
37 * @dest_keyring: Keyring being linked to.
38 * @type: The type of key being added.
39 * @payload: The payload of the new key.
40 * @restriction_key: A ring of keys that can be used to vouch for the new cert.
42 * Restrict the addition of keys into a keyring based on the key-to-be-added
43 * being vouched for by a key in the built in system keyring.
45 int restrict_link_by_builtin_trusted(struct key
*dest_keyring
,
46 const struct key_type
*type
,
47 const union key_payload
*payload
,
48 struct key
*restriction_key
)
50 return restrict_link_by_signature(dest_keyring
, type
, payload
,
51 builtin_trusted_keys
);
54 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
56 * restrict_link_by_builtin_and_secondary_trusted - Restrict keyring
57 * addition by both built-in and secondary keyrings.
58 * @dest_keyring: Keyring being linked to.
59 * @type: The type of key being added.
60 * @payload: The payload of the new key.
61 * @restrict_key: A ring of keys that can be used to vouch for the new cert.
63 * Restrict the addition of keys into a keyring based on the key-to-be-added
64 * being vouched for by a key in either the built-in or the secondary system
67 int restrict_link_by_builtin_and_secondary_trusted(
68 struct key
*dest_keyring
,
69 const struct key_type
*type
,
70 const union key_payload
*payload
,
71 struct key
*restrict_key
)
73 /* If we have a secondary trusted keyring, then that contains a link
74 * through to the builtin keyring and the search will follow that link.
76 if (type
== &key_type_keyring
&&
77 dest_keyring
== secondary_trusted_keys
&&
78 payload
== &builtin_trusted_keys
->payload
)
79 /* Allow the builtin keyring to be added to the secondary */
82 return restrict_link_by_signature(dest_keyring
, type
, payload
,
83 secondary_trusted_keys
);
87 * Allocate a struct key_restriction for the "builtin and secondary trust"
88 * keyring. Only for use in system_trusted_keyring_init().
90 static __init
struct key_restriction
*get_builtin_and_secondary_restriction(void)
92 struct key_restriction
*restriction
;
94 restriction
= kzalloc(sizeof(struct key_restriction
), GFP_KERNEL
);
97 panic("Can't allocate secondary trusted keyring restriction\n");
99 if (IS_ENABLED(CONFIG_INTEGRITY_MACHINE_KEYRING
))
100 restriction
->check
= restrict_link_by_builtin_secondary_and_machine
;
102 restriction
->check
= restrict_link_by_builtin_and_secondary_trusted
;
107 #ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
108 void __init
set_machine_trusted_keys(struct key
*keyring
)
110 machine_trusted_keys
= keyring
;
112 if (key_link(secondary_trusted_keys
, machine_trusted_keys
) < 0)
113 panic("Can't link (machine) trusted keyrings\n");
117 * restrict_link_by_builtin_secondary_and_machine - Restrict keyring addition.
118 * @dest_keyring: Keyring being linked to.
119 * @type: The type of key being added.
120 * @payload: The payload of the new key.
121 * @restrict_key: A ring of keys that can be used to vouch for the new cert.
123 * Restrict the addition of keys into a keyring based on the key-to-be-added
124 * being vouched for by a key in either the built-in, the secondary, or
125 * the machine keyrings.
127 int restrict_link_by_builtin_secondary_and_machine(
128 struct key
*dest_keyring
,
129 const struct key_type
*type
,
130 const union key_payload
*payload
,
131 struct key
*restrict_key
)
133 if (machine_trusted_keys
&& type
== &key_type_keyring
&&
134 dest_keyring
== secondary_trusted_keys
&&
135 payload
== &machine_trusted_keys
->payload
)
136 /* Allow the machine keyring to be added to the secondary */
139 return restrict_link_by_builtin_and_secondary_trusted(dest_keyring
, type
,
140 payload
, restrict_key
);
145 * Create the trusted keyrings
147 static __init
int system_trusted_keyring_init(void)
149 pr_notice("Initialise system trusted keyrings\n");
151 builtin_trusted_keys
=
152 keyring_alloc(".builtin_trusted_keys",
153 GLOBAL_ROOT_UID
, GLOBAL_ROOT_GID
, current_cred(),
154 ((KEY_POS_ALL
& ~KEY_POS_SETATTR
) |
155 KEY_USR_VIEW
| KEY_USR_READ
| KEY_USR_SEARCH
),
156 KEY_ALLOC_NOT_IN_QUOTA
,
158 if (IS_ERR(builtin_trusted_keys
))
159 panic("Can't allocate builtin trusted keyring\n");
161 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
162 secondary_trusted_keys
=
163 keyring_alloc(".secondary_trusted_keys",
164 GLOBAL_ROOT_UID
, GLOBAL_ROOT_GID
, current_cred(),
165 ((KEY_POS_ALL
& ~KEY_POS_SETATTR
) |
166 KEY_USR_VIEW
| KEY_USR_READ
| KEY_USR_SEARCH
|
168 KEY_ALLOC_NOT_IN_QUOTA
,
169 get_builtin_and_secondary_restriction(),
171 if (IS_ERR(secondary_trusted_keys
))
172 panic("Can't allocate secondary trusted keyring\n");
174 if (key_link(secondary_trusted_keys
, builtin_trusted_keys
) < 0)
175 panic("Can't link trusted keyrings\n");
182 * Must be initialised before we try and load the keys into the keyring.
184 device_initcall(system_trusted_keyring_init
);
186 __init
int load_module_cert(struct key
*keyring
)
188 if (!IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG
))
191 pr_notice("Loading compiled-in module X.509 certificates\n");
193 return x509_load_certificate_list(system_certificate_list
,
194 module_cert_size
, keyring
);
198 * Load the compiled-in list of X.509 certificates.
200 static __init
int load_system_certificate_list(void)
205 pr_notice("Loading compiled-in X.509 certificates\n");
207 #ifdef CONFIG_MODULE_SIG
208 p
= system_certificate_list
;
209 size
= system_certificate_list_size
;
211 p
= system_certificate_list
+ module_cert_size
;
212 size
= system_certificate_list_size
- module_cert_size
;
215 return x509_load_certificate_list(p
, size
, builtin_trusted_keys
);
217 late_initcall(load_system_certificate_list
);
219 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
222 * verify_pkcs7_message_sig - Verify a PKCS#7-based signature on system data.
223 * @data: The data to be verified (NULL if expecting internal data).
224 * @len: Size of @data.
225 * @pkcs7: The PKCS#7 message that is the signature.
226 * @trusted_keys: Trusted keys to use (NULL for builtin trusted keys only,
227 * (void *)1UL for all trusted keys).
228 * @usage: The use to which the key is being put.
229 * @view_content: Callback to gain access to content.
230 * @ctx: Context for callback.
232 int verify_pkcs7_message_sig(const void *data
, size_t len
,
233 struct pkcs7_message
*pkcs7
,
234 struct key
*trusted_keys
,
235 enum key_being_used_for usage
,
236 int (*view_content
)(void *ctx
,
237 const void *data
, size_t len
,
243 /* The data should be detached - so we need to supply it. */
244 if (data
&& pkcs7_supply_detached_data(pkcs7
, data
, len
) < 0) {
245 pr_err("PKCS#7 signature with non-detached data\n");
250 ret
= pkcs7_verify(pkcs7
, usage
);
255 trusted_keys
= builtin_trusted_keys
;
256 } else if (trusted_keys
== VERIFY_USE_SECONDARY_KEYRING
) {
257 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
258 trusted_keys
= secondary_trusted_keys
;
260 trusted_keys
= builtin_trusted_keys
;
262 } else if (trusted_keys
== VERIFY_USE_PLATFORM_KEYRING
) {
263 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
264 trusted_keys
= platform_trusted_keys
;
270 pr_devel("PKCS#7 platform keyring is not available\n");
274 ret
= is_key_on_revocation_list(pkcs7
);
275 if (ret
!= -ENOKEY
) {
276 pr_devel("PKCS#7 platform key is on revocation list\n");
280 ret
= pkcs7_validate_trust(pkcs7
, trusted_keys
);
283 pr_devel("PKCS#7 signature not signed with a trusted key\n");
290 ret
= pkcs7_get_content_data(pkcs7
, &data
, &len
, &asn1hdrlen
);
293 pr_devel("PKCS#7 message does not contain data\n");
297 ret
= view_content(ctx
, data
, len
, asn1hdrlen
);
301 pr_devel("<==%s() = %d\n", __func__
, ret
);
306 * verify_pkcs7_signature - Verify a PKCS#7-based signature on system data.
307 * @data: The data to be verified (NULL if expecting internal data).
308 * @len: Size of @data.
309 * @raw_pkcs7: The PKCS#7 message that is the signature.
310 * @pkcs7_len: The size of @raw_pkcs7.
311 * @trusted_keys: Trusted keys to use (NULL for builtin trusted keys only,
312 * (void *)1UL for all trusted keys).
313 * @usage: The use to which the key is being put.
314 * @view_content: Callback to gain access to content.
315 * @ctx: Context for callback.
317 int verify_pkcs7_signature(const void *data
, size_t len
,
318 const void *raw_pkcs7
, size_t pkcs7_len
,
319 struct key
*trusted_keys
,
320 enum key_being_used_for usage
,
321 int (*view_content
)(void *ctx
,
322 const void *data
, size_t len
,
326 struct pkcs7_message
*pkcs7
;
329 pkcs7
= pkcs7_parse_message(raw_pkcs7
, pkcs7_len
);
331 return PTR_ERR(pkcs7
);
333 ret
= verify_pkcs7_message_sig(data
, len
, pkcs7
, trusted_keys
, usage
,
336 pkcs7_free_message(pkcs7
);
337 pr_devel("<==%s() = %d\n", __func__
, ret
);
340 EXPORT_SYMBOL_GPL(verify_pkcs7_signature
);
342 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
344 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
345 void __init
set_platform_trusted_keys(struct key
*keyring
)
347 platform_trusted_keys
= keyring
;