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
21struct key *system_trusted_keyring;
22EXPORT_SYMBOL_GPL(system_trusted_keyring);
23
24extern __initconst const u8 system_certificate_list[];
25extern __initconst const unsigned long system_certificate_list_size;
26
27/*
28 * Load the compiled-in keys
29 */
30static __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 | KEY_USR_SEARCH),
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	set_bit(KEY_FLAG_TRUSTED_ONLY, &system_trusted_keyring->flags);
44	return 0;
45}
46
47/*
48 * Must be initialised before we try and load the keys into the keyring.
49 */
50device_initcall(system_trusted_keyring_init);
51
52/*
53 * Load the compiled-in list of X.509 certificates.
54 */
55static __init int load_system_certificate_list(void)
56{
57	key_ref_t key;
58	const u8 *p, *end;
59	size_t plen;
60
61	pr_notice("Loading compiled-in X.509 certificates\n");
62
63	p = system_certificate_list;
64	end = p + system_certificate_list_size;
65	while (p < end) {
66		/* Each cert begins with an ASN.1 SEQUENCE tag and must be more
67		 * than 256 bytes in size.
68		 */
69		if (end - p < 4)
70			goto dodgy_cert;
71		if (p[0] != 0x30 &&
72		    p[1] != 0x82)
73			goto dodgy_cert;
74		plen = (p[2] << 8) | p[3];
75		plen += 4;
76		if (plen > end - p)
77			goto dodgy_cert;
78
79		key = key_create_or_update(make_key_ref(system_trusted_keyring, 1),
80					   "asymmetric",
81					   NULL,
82					   p,
83					   plen,
84					   ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
85					   KEY_USR_VIEW | KEY_USR_READ),
86					   KEY_ALLOC_NOT_IN_QUOTA |
87					   KEY_ALLOC_TRUSTED);
88		if (IS_ERR(key)) {
89			pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
90			       PTR_ERR(key));
91		} else {
92			set_bit(KEY_FLAG_BUILTIN, &key_ref_to_ptr(key)->flags);
93			pr_notice("Loaded X.509 cert '%s'\n",
94				  key_ref_to_ptr(key)->description);
95			key_ref_put(key);
96		}
97		p += plen;
98	}
99
100	return 0;
101
102dodgy_cert:
103	pr_err("Problem parsing in-kernel X.509 certificate list\n");
104	return 0;
105}
106late_initcall(load_system_certificate_list);
107