1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* System hash blacklist.
4 * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
8 #define pr_fmt(fmt) "blacklist: "fmt
9 #include <linux/module.h>
10 #include <linux/slab.h>
11 #include <linux/key.h>
12 #include <linux/key-type.h>
13 #include <linux/sched.h>
14 #include <linux/ctype.h>
15 #include <linux/err.h>
16 #include <linux/seq_file.h>
17 #include <keys/system_keyring.h>
18 #include "blacklist.h"
21 static struct key *blacklist_keyring;
23 #ifdef CONFIG_SYSTEM_REVOCATION_LIST
24 extern __initconst const u8 revocation_certificate_list[];
25 extern __initconst const unsigned long revocation_certificate_list_size;
29 * The description must be a type prefix, a colon and then an even number of
30 * hex digits. The hash is kept in the description.
32 static int blacklist_vet_description(const char *desc)
45 for (; *desc; desc++) {
57 * The hash to be blacklisted is expected to be in the description. There will
60 static int blacklist_preparse(struct key_preparsed_payload *prep)
62 if (prep->datalen > 0)
67 static void blacklist_free_preparse(struct key_preparsed_payload *prep)
71 static void blacklist_describe(const struct key *key, struct seq_file *m)
73 seq_puts(m, key->description);
76 static struct key_type key_type_blacklist = {
78 .vet_description = blacklist_vet_description,
79 .preparse = blacklist_preparse,
80 .free_preparse = blacklist_free_preparse,
81 .instantiate = generic_key_instantiate,
82 .describe = blacklist_describe,
86 * mark_hash_blacklisted - Add a hash to the system blacklist
87 * @hash - The hash as a hex string with a type prefix (eg. "tbs:23aa429783")
89 int mark_hash_blacklisted(const char *hash)
93 key = key_create_or_update(make_key_ref(blacklist_keyring, true),
98 ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
100 KEY_ALLOC_NOT_IN_QUOTA |
103 pr_err("Problem blacklisting hash (%ld)\n", PTR_ERR(key));
110 * is_hash_blacklisted - Determine if a hash is blacklisted
111 * @hash: The hash to be checked as a binary blob
112 * @hash_len: The length of the binary hash
113 * @type: Type of hash
115 int is_hash_blacklisted(const u8 *hash, size_t hash_len, const char *type)
118 size_t type_len = strlen(type);
122 buffer = kmalloc(type_len + 1 + hash_len * 2 + 1, GFP_KERNEL);
125 p = memcpy(buffer, type, type_len);
128 bin2hex(p, hash, hash_len);
132 kref = keyring_search(make_key_ref(blacklist_keyring, true),
133 &key_type_blacklist, buffer, false);
142 EXPORT_SYMBOL_GPL(is_hash_blacklisted);
144 int is_binary_blacklisted(const u8 *hash, size_t hash_len)
146 if (is_hash_blacklisted(hash, hash_len, "bin") == -EKEYREJECTED)
151 EXPORT_SYMBOL_GPL(is_binary_blacklisted);
153 #ifdef CONFIG_SYSTEM_REVOCATION_LIST
155 * add_key_to_revocation_list - Add a revocation certificate to the blacklist
156 * @data: The data blob containing the certificate
157 * @size: The size of data blob
159 int add_key_to_revocation_list(const char *data, size_t size)
163 key = key_create_or_update(make_key_ref(blacklist_keyring, true),
168 ((KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW),
169 KEY_ALLOC_NOT_IN_QUOTA | KEY_ALLOC_BUILT_IN);
172 pr_err("Problem with revocation key (%ld)\n", PTR_ERR(key));
180 * is_key_on_revocation_list - Determine if the key for a PKCS#7 message is revoked
181 * @pkcs7: The PKCS#7 message to check
183 int is_key_on_revocation_list(struct pkcs7_message *pkcs7)
187 ret = pkcs7_validate_trust(pkcs7, blacklist_keyring);
190 return -EKEYREJECTED;
197 * Initialise the blacklist
199 static int __init blacklist_init(void)
201 const char *const *bl;
203 if (register_key_type(&key_type_blacklist) < 0)
204 panic("Can't allocate system blacklist key type\n");
207 keyring_alloc(".blacklist",
208 KUIDT_INIT(0), KGIDT_INIT(0),
210 (KEY_POS_ALL & ~KEY_POS_SETATTR) |
211 KEY_USR_VIEW | KEY_USR_READ |
213 KEY_ALLOC_NOT_IN_QUOTA |
216 if (IS_ERR(blacklist_keyring))
217 panic("Can't allocate system blacklist keyring\n");
219 for (bl = blacklist_hashes; *bl; bl++)
220 if (mark_hash_blacklisted(*bl) < 0)
221 pr_err("- blacklisting failed\n");
226 * Must be initialised before we try and load the keys into the keyring.
228 device_initcall(blacklist_init);
230 #ifdef CONFIG_SYSTEM_REVOCATION_LIST
232 * Load the compiled-in list of revocation X.509 certificates.
234 static __init int load_revocation_certificate_list(void)
236 if (revocation_certificate_list_size)
237 pr_notice("Loading compiled-in revocation X.509 certificates\n");
239 return load_certificate_list(revocation_certificate_list, revocation_certificate_list_size,
242 late_initcall(load_revocation_certificate_list);