1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2013 Intel Corporation
6 * Dmitry Kasatkin <dmitry.kasatkin@intel.com>
10 #include <linux/ratelimit.h>
11 #include <linux/key-type.h>
12 #include <crypto/public_key.h>
13 #include <crypto/hash_info.h>
14 #include <keys/asymmetric-type.h>
15 #include <keys/system_keyring.h>
17 #include "integrity.h"
20 * Request an asymmetric key.
22 static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
27 sprintf(name, "id:%08x", keyid);
29 pr_debug("key search: \"%s\"\n", name);
31 key = get_ima_blacklist_keyring();
35 kref = keyring_search(make_key_ref(key, 1),
36 &key_type_asymmetric, name, true);
38 pr_err("Key '%s' is in ima_blacklist_keyring\n", name);
39 return ERR_PTR(-EKEYREJECTED);
44 /* search in specific keyring */
47 kref = keyring_search(make_key_ref(keyring, 1),
48 &key_type_asymmetric, name, true);
52 key = key_ref_to_ptr(kref);
54 key = request_key(&key_type_asymmetric, name, NULL);
58 pr_err_ratelimited("Request for unknown key '%s' err %ld\n",
60 switch (PTR_ERR(key)) {
61 /* Hide some search errors */
65 return ERR_PTR(-ENOKEY);
71 pr_debug("%s() = 0 [%x]\n", __func__, key_serial(key));
76 int asymmetric_verify(struct key *keyring, const char *sig,
77 int siglen, const char *data, int datalen)
79 struct public_key_signature pks;
80 struct signature_v2_hdr *hdr = (struct signature_v2_hdr *)sig;
84 if (siglen <= sizeof(*hdr))
87 siglen -= sizeof(*hdr);
89 if (siglen != be16_to_cpu(hdr->sig_size))
92 if (hdr->hash_algo >= HASH_ALGO__LAST)
95 key = request_asymmetric_key(keyring, be32_to_cpu(hdr->keyid));
99 memset(&pks, 0, sizeof(pks));
101 pks.hash_algo = hash_algo_name[hdr->hash_algo];
102 if (hdr->hash_algo == HASH_ALGO_STREEBOG_256 ||
103 hdr->hash_algo == HASH_ALGO_STREEBOG_512) {
104 /* EC-RDSA and Streebog should go together. */
105 pks.pkey_algo = "ecrdsa";
106 pks.encoding = "raw";
108 pks.pkey_algo = "rsa";
109 pks.encoding = "pkcs1";
111 pks.digest = (u8 *)data;
112 pks.digest_size = datalen;
115 ret = verify_signature(key, &pks);
117 pr_debug("%s() = %d\n", __func__, ret);
122 * integrity_kernel_module_request - prevent crypto-pkcs1pad(rsa,*) requests
123 * @kmod_name: kernel module name
125 * We have situation, when public_key_verify_signature() in case of RSA
126 * algorithm use alg_name to store internal information in order to
127 * construct an algorithm on the fly, but crypto_larval_lookup() will try
128 * to use alg_name in order to load kernel module with same name.
129 * Since we don't have any real "crypto-pkcs1pad(rsa,*)" kernel modules,
130 * we are safe to fail such module request from crypto_larval_lookup().
132 * In this way we prevent modprobe execution during digsig verification
133 * and avoid possible deadlock if modprobe and/or it's dependencies
134 * also signed with digsig.
136 int integrity_kernel_module_request(char *kmod_name)
138 if (strncmp(kmod_name, "crypto-pkcs1pad(rsa,", 20) == 0)