1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Machine keyring routines.
4 *
5 * Copyright (c) 2021, Oracle and/or its affiliates.
6 */
7
8 #include <linux/efi.h>
9 #include "../integrity.h"
10
11 static bool trust_mok;
12
machine_keyring_init(void)13 static __init int machine_keyring_init(void)
14 {
15 int rc;
16
17 rc = integrity_init_keyring(INTEGRITY_KEYRING_MACHINE);
18 if (rc)
19 return rc;
20
21 pr_notice("Machine keyring initialized\n");
22 return 0;
23 }
24 device_initcall(machine_keyring_init);
25
add_to_machine_keyring(const char * source,const void * data,size_t len)26 void __init add_to_machine_keyring(const char *source, const void *data, size_t len)
27 {
28 key_perm_t perm;
29 int rc;
30
31 perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW;
32 rc = integrity_load_cert(INTEGRITY_KEYRING_MACHINE, source, data, len, perm);
33
34 /*
35 * Some MOKList keys may not pass the machine keyring restrictions.
36 * If the restriction check does not pass and the platform keyring
37 * is configured, try to add it into that keyring instead.
38 */
39 if (rc && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING))
40 rc = integrity_load_cert(INTEGRITY_KEYRING_PLATFORM, source,
41 data, len, perm);
42
43 if (rc)
44 pr_info("Error adding keys to machine keyring %s\n", source);
45 }
46
47 /*
48 * Try to load the MokListTrustedRT MOK variable to see if we should trust
49 * the MOK keys within the kernel. It is not an error if this variable
50 * does not exist. If it does not exist, MOK keys should not be trusted
51 * within the machine keyring.
52 */
uefi_check_trust_mok_keys(void)53 static __init bool uefi_check_trust_mok_keys(void)
54 {
55 struct efi_mokvar_table_entry *mokvar_entry;
56
57 mokvar_entry = efi_mokvar_entry_find("MokListTrustedRT");
58
59 if (mokvar_entry)
60 return true;
61
62 return false;
63 }
64
trust_moklist(void)65 bool __init trust_moklist(void)
66 {
67 static bool initialized;
68
69 if (!initialized) {
70 initialized = true;
71
72 if (uefi_check_trust_mok_keys())
73 trust_mok = true;
74 }
75
76 return trust_mok;
77 }
78