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 
14 static efi_guid_t efi_cert_x509_guid __initdata = EFI_CERT_X509_GUID;
15 static efi_guid_t efi_cert_x509_sha256_guid __initdata =
16 	EFI_CERT_X509_SHA256_GUID;
17 static efi_guid_t efi_cert_sha256_guid __initdata = EFI_CERT_SHA256_GUID;
18 
19 /*
20  * Blacklist an X509 TBS hash.
21  */
uefi_blacklist_x509_tbs(const char * source,const void * data,size_t len)22 static __init void uefi_blacklist_x509_tbs(const char *source,
23 					   const void *data, size_t len)
24 {
25 	mark_hash_blacklisted(data, len, BLACKLIST_HASH_X509_TBS);
26 }
27 
28 /*
29  * Blacklist the hash of an executable.
30  */
uefi_blacklist_binary(const char * source,const void * data,size_t len)31 static __init void uefi_blacklist_binary(const char *source,
32 					 const void *data, size_t len)
33 {
34 	mark_hash_blacklisted(data, len, BLACKLIST_HASH_BINARY);
35 }
36 
37 /*
38  * Add an X509 cert to the revocation list.
39  */
uefi_revocation_list_x509(const char * source,const void * data,size_t len)40 static __init void uefi_revocation_list_x509(const char *source,
41 					     const void *data, size_t len)
42 {
43 	add_key_to_revocation_list(data, len);
44 }
45 
46 /*
47  * Return the appropriate handler for particular signature list types found in
48  * the UEFI db tables.
49  */
get_handler_for_db(const efi_guid_t * sig_type)50 __init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type)
51 {
52 	if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
53 		return add_to_platform_keyring;
54 	return NULL;
55 }
56 
57 /*
58  * Return the appropriate handler for particular signature list types found in
59  * the MokListRT tables.
60  */
get_handler_for_mok(const efi_guid_t * sig_type)61 __init efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type)
62 {
63 	if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) {
64 		if (IS_ENABLED(CONFIG_INTEGRITY_MACHINE_KEYRING) && trust_moklist())
65 			return add_to_machine_keyring;
66 		else
67 			return add_to_platform_keyring;
68 	}
69 	return NULL;
70 }
71 
72 /*
73  * Return the appropriate handler for particular signature list types found in
74  * the UEFI dbx and MokListXRT tables.
75  */
get_handler_for_dbx(const efi_guid_t * sig_type)76 __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type)
77 {
78 	if (efi_guidcmp(*sig_type, efi_cert_x509_sha256_guid) == 0)
79 		return uefi_blacklist_x509_tbs;
80 	if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0)
81 		return uefi_blacklist_binary;
82 	if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
83 		return uefi_revocation_list_x509;
84 	return NULL;
85 }
86