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1 /* System trusted keyring for trusted public keys
2  *
3  * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
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.
10  */
11 
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 <keys/asymmetric-type.h>
18 #include <keys/system_keyring.h>
19 #include "module-internal.h"
20 
21 struct key *system_trusted_keyring;
22 EXPORT_SYMBOL_GPL(system_trusted_keyring);
23 
24 extern __initconst const u8 system_certificate_list[];
25 extern __initconst const u8 system_certificate_list_end[];
26 
27 /*
28  * Load the compiled-in keys
29  */
system_trusted_keyring_init(void)30 static __init int system_trusted_keyring_init(void)
31 {
32 	pr_notice("Initialise system trusted keyring\n");
33 
34 	system_trusted_keyring =
35 		keyring_alloc(".system_keyring",
36 			      KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
37 			      ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
38 			       KEY_USR_VIEW | KEY_USR_READ),
39 			      KEY_ALLOC_NOT_IN_QUOTA, NULL);
40 	if (IS_ERR(system_trusted_keyring))
41 		panic("Can't allocate system trusted keyring\n");
42 
43 	return 0;
44 }
45 
46 /*
47  * Must be initialised before we try and load the keys into the keyring.
48  */
49 device_initcall(system_trusted_keyring_init);
50 
51 /*
52  * Load the compiled-in list of X.509 certificates.
53  */
load_system_certificate_list(void)54 static __init int load_system_certificate_list(void)
55 {
56 	key_ref_t key;
57 	const u8 *p, *end;
58 	size_t plen;
59 
60 	pr_notice("Loading compiled-in X.509 certificates\n");
61 
62 	end = system_certificate_list_end;
63 	p = system_certificate_list;
64 	while (p < end) {
65 		/* Each cert begins with an ASN.1 SEQUENCE tag and must be more
66 		 * than 256 bytes in size.
67 		 */
68 		if (end - p < 4)
69 			goto dodgy_cert;
70 		if (p[0] != 0x30 &&
71 		    p[1] != 0x82)
72 			goto dodgy_cert;
73 		plen = (p[2] << 8) | p[3];
74 		plen += 4;
75 		if (plen > end - p)
76 			goto dodgy_cert;
77 
78 		key = key_create_or_update(make_key_ref(system_trusted_keyring, 1),
79 					   "asymmetric",
80 					   NULL,
81 					   p,
82 					   plen,
83 					   (KEY_POS_ALL & ~KEY_POS_SETATTR) |
84 					   KEY_USR_VIEW,
85 					   KEY_ALLOC_NOT_IN_QUOTA);
86 		if (IS_ERR(key)) {
87 			pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
88 			       PTR_ERR(key));
89 		} else {
90 			pr_notice("Loaded X.509 cert '%s'\n",
91 				  key_ref_to_ptr(key)->description);
92 			key_ref_put(key);
93 		}
94 		p += plen;
95 	}
96 
97 	return 0;
98 
99 dodgy_cert:
100 	pr_err("Problem parsing in-kernel X.509 certificate list\n");
101 	return 0;
102 }
103 late_initcall(load_system_certificate_list);
104