1 /* System trusted keyring for trusted public keys
3 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
12 #include <linux/export.h>
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/cred.h>
16 #include <linux/err.h>
17 #include <linux/slab.h>
18 #include <linux/verification.h>
19 #include <keys/asymmetric-type.h>
20 #include <keys/system_keyring.h>
21 #include <crypto/pkcs7.h>
24 static struct key
*builtin_trusted_keys
;
25 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
26 static struct key
*secondary_trusted_keys
;
29 extern __initconst
const u8 system_certificate_list
[];
30 extern __initconst
const unsigned long system_certificate_list_size
;
33 * restrict_link_to_builtin_trusted - Restrict keyring addition by built in CA
35 * Restrict the addition of keys into a keyring based on the key-to-be-added
36 * being vouched for by a key in the built in system keyring.
38 int restrict_link_by_builtin_trusted(struct key
*dest_keyring
,
39 const struct key_type
*type
,
40 const union key_payload
*payload
,
41 struct key
*restriction_key
)
43 return restrict_link_by_signature(dest_keyring
, type
, payload
,
44 builtin_trusted_keys
);
47 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
49 * restrict_link_by_builtin_and_secondary_trusted - Restrict keyring
50 * addition by both builtin and secondary keyrings
52 * Restrict the addition of keys into a keyring based on the key-to-be-added
53 * being vouched for by a key in either the built-in or the secondary system
56 int restrict_link_by_builtin_and_secondary_trusted(
57 struct key
*dest_keyring
,
58 const struct key_type
*type
,
59 const union key_payload
*payload
,
60 struct key
*restrict_key
)
62 /* If we have a secondary trusted keyring, then that contains a link
63 * through to the builtin keyring and the search will follow that link.
65 if (type
== &key_type_keyring
&&
66 dest_keyring
== secondary_trusted_keys
&&
67 payload
== &builtin_trusted_keys
->payload
)
68 /* Allow the builtin keyring to be added to the secondary */
71 return restrict_link_by_signature(dest_keyring
, type
, payload
,
72 secondary_trusted_keys
);
76 * Allocate a struct key_restriction for the "builtin and secondary trust"
77 * keyring. Only for use in system_trusted_keyring_init().
79 static __init
struct key_restriction
*get_builtin_and_secondary_restriction(void)
81 struct key_restriction
*restriction
;
83 restriction
= kzalloc(sizeof(struct key_restriction
), GFP_KERNEL
);
86 panic("Can't allocate secondary trusted keyring restriction\n");
88 restriction
->check
= restrict_link_by_builtin_and_secondary_trusted
;
95 * Create the trusted keyrings
97 static __init
int system_trusted_keyring_init(void)
99 pr_notice("Initialise system trusted keyrings\n");
101 builtin_trusted_keys
=
102 keyring_alloc(".builtin_trusted_keys",
103 KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
104 ((KEY_POS_ALL
& ~KEY_POS_SETATTR
) |
105 KEY_USR_VIEW
| KEY_USR_READ
| KEY_USR_SEARCH
),
106 KEY_ALLOC_NOT_IN_QUOTA
,
108 if (IS_ERR(builtin_trusted_keys
))
109 panic("Can't allocate builtin trusted keyring\n");
111 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
112 secondary_trusted_keys
=
113 keyring_alloc(".secondary_trusted_keys",
114 KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
115 ((KEY_POS_ALL
& ~KEY_POS_SETATTR
) |
116 KEY_USR_VIEW
| KEY_USR_READ
| KEY_USR_SEARCH
|
118 KEY_ALLOC_NOT_IN_QUOTA
,
119 get_builtin_and_secondary_restriction(),
121 if (IS_ERR(secondary_trusted_keys
))
122 panic("Can't allocate secondary trusted keyring\n");
124 if (key_link(secondary_trusted_keys
, builtin_trusted_keys
) < 0)
125 panic("Can't link trusted keyrings\n");
132 * Must be initialised before we try and load the keys into the keyring.
134 device_initcall(system_trusted_keyring_init
);
137 * Load the compiled-in list of X.509 certificates.
139 static __init
int load_system_certificate_list(void)
145 pr_notice("Loading compiled-in X.509 certificates\n");
147 p
= system_certificate_list
;
148 end
= p
+ system_certificate_list_size
;
150 /* Each cert begins with an ASN.1 SEQUENCE tag and must be more
151 * than 256 bytes in size.
158 plen
= (p
[2] << 8) | p
[3];
163 key
= key_create_or_update(make_key_ref(builtin_trusted_keys
, 1),
168 ((KEY_POS_ALL
& ~KEY_POS_SETATTR
) |
169 KEY_USR_VIEW
| KEY_USR_READ
),
170 KEY_ALLOC_NOT_IN_QUOTA
|
172 KEY_ALLOC_BYPASS_RESTRICTION
);
174 pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
178 pr_notice("Loaded X.509 cert '%s'\n",
179 key_ref_to_ptr(key
)->description
);
188 pr_err("Problem parsing in-kernel X.509 certificate list\n");
191 late_initcall(load_system_certificate_list
);
193 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
196 * verify_pkcs7_signature - Verify a PKCS#7-based signature on system data.
197 * @data: The data to be verified (NULL if expecting internal data).
198 * @len: Size of @data.
199 * @raw_pkcs7: The PKCS#7 message that is the signature.
200 * @pkcs7_len: The size of @raw_pkcs7.
201 * @trusted_keys: Trusted keys to use (NULL for builtin trusted keys only,
202 * (void *)1UL for all trusted keys).
203 * @usage: The use to which the key is being put.
204 * @view_content: Callback to gain access to content.
205 * @ctx: Context for callback.
207 int verify_pkcs7_signature(const void *data
, size_t len
,
208 const void *raw_pkcs7
, size_t pkcs7_len
,
209 struct key
*trusted_keys
,
210 enum key_being_used_for usage
,
211 int (*view_content
)(void *ctx
,
212 const void *data
, size_t len
,
216 struct pkcs7_message
*pkcs7
;
219 pkcs7
= pkcs7_parse_message(raw_pkcs7
, pkcs7_len
);
221 return PTR_ERR(pkcs7
);
223 /* The data should be detached - so we need to supply it. */
224 if (data
&& pkcs7_supply_detached_data(pkcs7
, data
, len
) < 0) {
225 pr_err("PKCS#7 signature with non-detached data\n");
230 ret
= pkcs7_verify(pkcs7
, usage
);
235 trusted_keys
= builtin_trusted_keys
;
236 } else if (trusted_keys
== VERIFY_USE_SECONDARY_KEYRING
) {
237 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
238 trusted_keys
= secondary_trusted_keys
;
240 trusted_keys
= builtin_trusted_keys
;
243 ret
= pkcs7_validate_trust(pkcs7
, trusted_keys
);
246 pr_err("PKCS#7 signature not signed with a trusted key\n");
253 ret
= pkcs7_get_content_data(pkcs7
, &data
, &len
, &asn1hdrlen
);
256 pr_devel("PKCS#7 message does not contain data\n");
260 ret
= view_content(ctx
, data
, len
, asn1hdrlen
);
264 pkcs7_free_message(pkcs7
);
265 pr_devel("<==%s() = %d\n", __func__
, ret
);
268 EXPORT_SYMBOL_GPL(verify_pkcs7_signature
);
270 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
272 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
274 * add_trusted_secondary_key - Add to secondary keyring with no validation
275 * @source: Source of key
276 * @data: The blob holding the key
277 * @len: The length of the data blob
279 * Add a key to the secondary keyring without checking its trust chain. This
280 * is available only during kernel initialisation.
282 void __init
add_trusted_secondary_key(const char *source
,
283 const void *data
, size_t len
)
287 key
= key_create_or_update(make_key_ref(secondary_trusted_keys
, 1),
290 (KEY_POS_ALL
& ~KEY_POS_SETATTR
) |
292 KEY_ALLOC_NOT_IN_QUOTA
|
293 KEY_ALLOC_BYPASS_RESTRICTION
);
296 pr_err("Problem loading %s X.509 certificate (%ld)\n",
297 source
, PTR_ERR(key
));
299 pr_notice("Loaded %s cert '%s' linked to secondary sys keyring\n",
300 source
, key_ref_to_ptr(key
)->description
);
302 #endif /* CONFIG_SECONDARY_TRUSTED_KEYRING */