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
13static efi_guid_t efi_cert_x509_guid __initdata = EFI_CERT_X509_GUID;
14static efi_guid_t efi_cert_x509_sha256_guid __initdata =
15 EFI_CERT_X509_SHA256_GUID;
16static efi_guid_t efi_cert_sha256_guid __initdata = EFI_CERT_SHA256_GUID;
17
18/*
19 * Blacklist a hash.
20 */
21static __init void uefi_blacklist_hash(const char *source, const void *data,
22 size_t len, const char *type,
23 size_t type_len)
24{
25 char *hash, *p;
26
27 hash = kmalloc(type_len + len * 2 + 1, GFP_KERNEL);
28 if (!hash)
29 return;
30 p = memcpy(hash, type, type_len);
31 p += type_len;
32 bin2hex(p, data, len);
33 p += len * 2;
34 *p = 0;
35
36 mark_hash_blacklisted(hash);
37 kfree(hash);
38}
39
40/*
41 * Blacklist an X509 TBS hash.
42 */
43static __init void uefi_blacklist_x509_tbs(const char *source,
44 const void *data, size_t len)
45{
46 uefi_blacklist_hash(source, data, len, "tbs:", 4);
47}
48
49/*
50 * Blacklist the hash of an executable.
51 */
52static __init void uefi_blacklist_binary(const char *source,
53 const void *data, size_t len)
54{
55 uefi_blacklist_hash(source, data, len, "bin:", 4);
56}
57
58/*
59 * Return the appropriate handler for particular signature list types found in
60 * the UEFI db and MokListRT tables.
61 */
62__init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type)
63{
64 if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
65 return add_to_platform_keyring;
66 return 0;
67}
68
69/*
70 * Return the appropriate handler for particular signature list types found in
71 * the UEFI dbx and MokListXRT tables.
72 */
73__init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type)
74{
75 if (efi_guidcmp(*sig_type, efi_cert_x509_sha256_guid) == 0)
76 return uefi_blacklist_x509_tbs;
77 if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0)
78 return uefi_blacklist_binary;
79 return 0;
80}