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>
21 static struct key
*builtin_trusted_keys
;
22 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
23 static struct key
*secondary_trusted_keys
;
25 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
26 static struct key
*platform_trusted_keys
;
29 extern __initconst
const u8 system_certificate_list
[];
30 extern __initconst
const unsigned long system_certificate_list_size
;
31 extern __initconst
const unsigned long module_cert_size
;
34 * restrict_link_to_builtin_trusted - Restrict keyring addition by built in CA
36 * Restrict the addition of keys into a keyring based on the key-to-be-added
37 * being vouched for by a key in the built in system keyring.
39 int restrict_link_by_builtin_trusted(struct key
*dest_keyring
,
40 const struct key_type
*type
,
41 const union key_payload
*payload
,
42 struct key
*restriction_key
)
44 return restrict_link_by_signature(dest_keyring
, type
, payload
,
45 builtin_trusted_keys
);
48 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
50 * restrict_link_by_builtin_and_secondary_trusted - Restrict keyring
51 * addition by both builtin and secondary keyrings
53 * Restrict the addition of keys into a keyring based on the key-to-be-added
54 * being vouched for by a key in either the built-in or the secondary system
57 int restrict_link_by_builtin_and_secondary_trusted(
58 struct key
*dest_keyring
,
59 const struct key_type
*type
,
60 const union key_payload
*payload
,
61 struct key
*restrict_key
)
63 /* If we have a secondary trusted keyring, then that contains a link
64 * through to the builtin keyring and the search will follow that link.
66 if (type
== &key_type_keyring
&&
67 dest_keyring
== secondary_trusted_keys
&&
68 payload
== &builtin_trusted_keys
->payload
)
69 /* Allow the builtin keyring to be added to the secondary */
72 return restrict_link_by_signature(dest_keyring
, type
, payload
,
73 secondary_trusted_keys
);
77 * Allocate a struct key_restriction for the "builtin and secondary trust"
78 * keyring. Only for use in system_trusted_keyring_init().
80 static __init
struct key_restriction
*get_builtin_and_secondary_restriction(void)
82 struct key_restriction
*restriction
;
84 restriction
= kzalloc(sizeof(struct key_restriction
), GFP_KERNEL
);
87 panic("Can't allocate secondary trusted keyring restriction\n");
89 restriction
->check
= restrict_link_by_builtin_and_secondary_trusted
;
96 * Create the trusted keyrings
98 static __init
int system_trusted_keyring_init(void)
100 pr_notice("Initialise system trusted keyrings\n");
102 builtin_trusted_keys
=
103 keyring_alloc(".builtin_trusted_keys",
104 GLOBAL_ROOT_UID
, GLOBAL_ROOT_GID
, current_cred(),
105 ((KEY_POS_ALL
& ~KEY_POS_SETATTR
) |
106 KEY_USR_VIEW
| KEY_USR_READ
| KEY_USR_SEARCH
),
107 KEY_ALLOC_NOT_IN_QUOTA
,
109 if (IS_ERR(builtin_trusted_keys
))
110 panic("Can't allocate builtin trusted keyring\n");
112 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
113 secondary_trusted_keys
=
114 keyring_alloc(".secondary_trusted_keys",
115 GLOBAL_ROOT_UID
, GLOBAL_ROOT_GID
, current_cred(),
116 ((KEY_POS_ALL
& ~KEY_POS_SETATTR
) |
117 KEY_USR_VIEW
| KEY_USR_READ
| KEY_USR_SEARCH
|
119 KEY_ALLOC_NOT_IN_QUOTA
,
120 get_builtin_and_secondary_restriction(),
122 if (IS_ERR(secondary_trusted_keys
))
123 panic("Can't allocate secondary trusted keyring\n");
125 if (key_link(secondary_trusted_keys
, builtin_trusted_keys
) < 0)
126 panic("Can't link trusted keyrings\n");
133 * Must be initialised before we try and load the keys into the keyring.
135 device_initcall(system_trusted_keyring_init
);
137 __init
int load_module_cert(struct key
*keyring
)
139 if (!IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG
))
142 pr_notice("Loading compiled-in module X.509 certificates\n");
144 return load_certificate_list(system_certificate_list
, module_cert_size
, keyring
);
148 * Load the compiled-in list of X.509 certificates.
150 static __init
int load_system_certificate_list(void)
155 pr_notice("Loading compiled-in X.509 certificates\n");
157 #ifdef CONFIG_MODULE_SIG
158 p
= system_certificate_list
;
159 size
= system_certificate_list_size
;
161 p
= system_certificate_list
+ module_cert_size
;
162 size
= system_certificate_list_size
- module_cert_size
;
165 return load_certificate_list(p
, size
, builtin_trusted_keys
);
167 late_initcall(load_system_certificate_list
);
169 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
172 * verify_pkcs7_message_sig - Verify a PKCS#7-based signature on system data.
173 * @data: The data to be verified (NULL if expecting internal data).
174 * @len: Size of @data.
175 * @pkcs7: The PKCS#7 message that is the signature.
176 * @trusted_keys: Trusted keys to use (NULL for builtin trusted keys only,
177 * (void *)1UL for all trusted keys).
178 * @usage: The use to which the key is being put.
179 * @view_content: Callback to gain access to content.
180 * @ctx: Context for callback.
182 int verify_pkcs7_message_sig(const void *data
, size_t len
,
183 struct pkcs7_message
*pkcs7
,
184 struct key
*trusted_keys
,
185 enum key_being_used_for usage
,
186 int (*view_content
)(void *ctx
,
187 const void *data
, size_t len
,
193 /* The data should be detached - so we need to supply it. */
194 if (data
&& pkcs7_supply_detached_data(pkcs7
, data
, len
) < 0) {
195 pr_err("PKCS#7 signature with non-detached data\n");
200 ret
= pkcs7_verify(pkcs7
, usage
);
205 trusted_keys
= builtin_trusted_keys
;
206 } else if (trusted_keys
== VERIFY_USE_SECONDARY_KEYRING
) {
207 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
208 trusted_keys
= secondary_trusted_keys
;
210 trusted_keys
= builtin_trusted_keys
;
212 } else if (trusted_keys
== VERIFY_USE_PLATFORM_KEYRING
) {
213 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
214 trusted_keys
= platform_trusted_keys
;
220 pr_devel("PKCS#7 platform keyring is not available\n");
224 ret
= is_key_on_revocation_list(pkcs7
);
225 if (ret
!= -ENOKEY
) {
226 pr_devel("PKCS#7 platform key is on revocation list\n");
230 ret
= pkcs7_validate_trust(pkcs7
, trusted_keys
);
233 pr_devel("PKCS#7 signature not signed with a trusted key\n");
240 ret
= pkcs7_get_content_data(pkcs7
, &data
, &len
, &asn1hdrlen
);
243 pr_devel("PKCS#7 message does not contain data\n");
247 ret
= view_content(ctx
, data
, len
, asn1hdrlen
);
251 pr_devel("<==%s() = %d\n", __func__
, ret
);
256 * verify_pkcs7_signature - Verify a PKCS#7-based signature on system data.
257 * @data: The data to be verified (NULL if expecting internal data).
258 * @len: Size of @data.
259 * @raw_pkcs7: The PKCS#7 message that is the signature.
260 * @pkcs7_len: The size of @raw_pkcs7.
261 * @trusted_keys: Trusted keys to use (NULL for builtin trusted keys only,
262 * (void *)1UL for all trusted keys).
263 * @usage: The use to which the key is being put.
264 * @view_content: Callback to gain access to content.
265 * @ctx: Context for callback.
267 int verify_pkcs7_signature(const void *data
, size_t len
,
268 const void *raw_pkcs7
, size_t pkcs7_len
,
269 struct key
*trusted_keys
,
270 enum key_being_used_for usage
,
271 int (*view_content
)(void *ctx
,
272 const void *data
, size_t len
,
276 struct pkcs7_message
*pkcs7
;
279 pkcs7
= pkcs7_parse_message(raw_pkcs7
, pkcs7_len
);
281 return PTR_ERR(pkcs7
);
283 ret
= verify_pkcs7_message_sig(data
, len
, pkcs7
, trusted_keys
, usage
,
286 pkcs7_free_message(pkcs7
);
287 pr_devel("<==%s() = %d\n", __func__
, ret
);
290 EXPORT_SYMBOL_GPL(verify_pkcs7_signature
);
292 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
294 #ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
295 void __init
set_platform_trusted_keys(struct key
*keyring
)
297 platform_trusted_keys
= keyring
;