1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * Copyright (C) 2018 IBM Corporation
4 */
5 #include <linux/efi.h>
6 #include <linux/module.h>
7 #include <linux/ima.h>
8 #include <asm/efi.h>
9
10 #ifndef arch_ima_efi_boot_mode
11 #define arch_ima_efi_boot_mode efi_secureboot_mode_unset
12 #endif
13
14 static enum efi_secureboot_mode get_sb_mode(void)
15 {
16 enum efi_secureboot_mode mode;
17
18 if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) {
19 pr_info("ima: secureboot mode unknown, no efi\n");
20 return efi_secureboot_mode_unknown;
21 }
22
23 mode = efi_get_secureboot_mode(efi.get_variable);
24 if (mode == efi_secureboot_mode_disabled)
25 pr_info("ima: secureboot mode disabled\n");
26 else if (mode == efi_secureboot_mode_unknown)
27 pr_info("ima: secureboot mode unknown\n");
28 else
29 pr_info("ima: secureboot mode enabled\n");
30 return mode;
31 }
32
33 bool arch_ima_get_secureboot(void)
34 {
35 static enum efi_secureboot_mode sb_mode;
36 static bool initialized;
37
38 if (!initialized && efi_enabled(EFI_BOOT)) {
39 sb_mode = arch_ima_efi_boot_mode;
40
41 if (sb_mode == efi_secureboot_mode_unset)
42 sb_mode = get_sb_mode();
43 initialized = true;
44 }
45
46 if (sb_mode == efi_secureboot_mode_enabled)
47 return true;
48 else
49 return false;
50 }
51
52 /* secureboot arch rules */
53 static const char * const sb_arch_rules[] = {
54 #if !IS_ENABLED(CONFIG_KEXEC_SIG)
55 "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig",
56 #endif /* CONFIG_KEXEC_SIG */
57 "measure func=KEXEC_KERNEL_CHECK",
58 #if !IS_ENABLED(CONFIG_MODULE_SIG)
59 "appraise func=MODULE_CHECK appraise_type=imasig",
60 #endif
61 #if IS_ENABLED(CONFIG_INTEGRITY_MACHINE_KEYRING) && IS_ENABLED(CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY)
62 "appraise func=POLICY_CHECK appraise_type=imasig",
63 #endif
64 "measure func=MODULE_CHECK",
65 NULL
66 };
67
68 const char * const *arch_get_ima_policy(void)
69 {
70 if (IS_ENABLED(CONFIG_IMA_ARCH_POLICY) && arch_ima_get_secureboot()) {
71 if (IS_ENABLED(CONFIG_MODULE_SIG))
72 set_module_sig_enforced();
73 if (IS_ENABLED(CONFIG_KEXEC_SIG))
74 set_kexec_sig_enforced();
75 return sb_arch_rules;
76 }
77 return NULL;
78 }
79
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