Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/kernel.h>
4#include <linux/sched.h>
5#include <linux/cred.h>
6#include <linux/err.h>
7#include <linux/efi.h>
8#include <linux/slab.h>
9#include <keys/asymmetric-type.h>
10#include <keys/system_keyring.h>
11#include "../integrity.h"
12#include "keyring_handler.h"
13
14static efi_guid_t efi_cert_x509_guid __initdata = EFI_CERT_X509_GUID;
15static efi_guid_t efi_cert_x509_sha256_guid __initdata =
16 EFI_CERT_X509_SHA256_GUID;
17static efi_guid_t efi_cert_sha256_guid __initdata = EFI_CERT_SHA256_GUID;
18
19/*
20 * Blacklist a hash.
21 */
22static __init void uefi_blacklist_hash(const char *source, const void *data,
23 size_t len, const char *type,
24 size_t type_len)
25{
26 char *hash, *p;
27
28 hash = kmalloc(type_len + len * 2 + 1, GFP_KERNEL);
29 if (!hash)
30 return;
31 p = memcpy(hash, type, type_len);
32 p += type_len;
33 bin2hex(p, data, len);
34 p += len * 2;
35 *p = 0;
36
37 mark_hash_blacklisted(hash);
38 kfree(hash);
39}
40
41/*
42 * Blacklist an X509 TBS hash.
43 */
44static __init void uefi_blacklist_x509_tbs(const char *source,
45 const void *data, size_t len)
46{
47 uefi_blacklist_hash(source, data, len, "tbs:", 4);
48}
49
50/*
51 * Blacklist the hash of an executable.
52 */
53static __init void uefi_blacklist_binary(const char *source,
54 const void *data, size_t len)
55{
56 uefi_blacklist_hash(source, data, len, "bin:", 4);
57}
58
59/*
60 * Add an X509 cert to the revocation list.
61 */
62static __init void uefi_revocation_list_x509(const char *source,
63 const void *data, size_t len)
64{
65 add_key_to_revocation_list(data, len);
66}
67
68/*
69 * Return the appropriate handler for particular signature list types found in
70 * the UEFI db tables.
71 */
72__init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type)
73{
74 if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
75 return add_to_platform_keyring;
76 return 0;
77}
78
79/*
80 * Return the appropriate handler for particular signature list types found in
81 * the MokListRT tables.
82 */
83__init efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type)
84{
85 if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) {
86 if (IS_ENABLED(CONFIG_INTEGRITY_MACHINE_KEYRING) && trust_moklist())
87 return add_to_machine_keyring;
88 else
89 return add_to_platform_keyring;
90 }
91 return 0;
92}
93
94/*
95 * Return the appropriate handler for particular signature list types found in
96 * the UEFI dbx and MokListXRT tables.
97 */
98__init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type)
99{
100 if (efi_guidcmp(*sig_type, efi_cert_x509_sha256_guid) == 0)
101 return uefi_blacklist_x509_tbs;
102 if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0)
103 return uefi_blacklist_binary;
104 if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
105 return uefi_revocation_list_x509;
106 return 0;
107}