2 * Copyright (C) 2013 Intel Corporation
5 * Dmitry Kasatkin <dmitry.kasatkin@intel.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, version 2 of the License.
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 #include <linux/err.h>
16 #include <linux/ratelimit.h>
17 #include <linux/key-type.h>
18 #include <crypto/public_key.h>
19 #include <keys/asymmetric-type.h>
20 #include <keys/system_keyring.h>
22 #include "integrity.h"
25 * Request an asymmetric key.
27 static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
32 sprintf(name, "id:%08x", keyid);
34 pr_debug("key search: \"%s\"\n", name);
36 key = get_ima_blacklist_keyring();
40 kref = keyring_search(make_key_ref(key, 1),
41 &key_type_asymmetric, name);
43 pr_err("Key '%s' is in ima_blacklist_keyring\n", name);
44 return ERR_PTR(-EKEYREJECTED);
49 /* search in specific keyring */
52 kref = keyring_search(make_key_ref(keyring, 1),
53 &key_type_asymmetric, name);
57 key = key_ref_to_ptr(kref);
59 key = request_key(&key_type_asymmetric, name, NULL);
63 pr_err_ratelimited("Request for unknown key '%s' err %ld\n",
65 switch (PTR_ERR(key)) {
66 /* Hide some search errors */
70 return ERR_PTR(-ENOKEY);
76 pr_debug("%s() = 0 [%x]\n", __func__, key_serial(key));
81 int asymmetric_verify(struct key *keyring, const char *sig,
82 int siglen, const char *data, int datalen)
84 struct public_key_signature pks;
85 struct signature_v2_hdr *hdr = (struct signature_v2_hdr *)sig;
89 if (siglen <= sizeof(*hdr))
92 siglen -= sizeof(*hdr);
94 if (siglen != __be16_to_cpu(hdr->sig_size))
97 if (hdr->hash_algo >= PKEY_HASH__LAST)
100 key = request_asymmetric_key(keyring, __be32_to_cpu(hdr->keyid));
104 memset(&pks, 0, sizeof(pks));
106 pks.pkey_hash_algo = hdr->hash_algo;
107 pks.digest = (u8 *)data;
108 pks.digest_size = datalen;
110 pks.rsa.s = mpi_read_raw_data(hdr->sig, siglen);
113 ret = verify_signature(key, &pks);
117 pr_debug("%s() = %d\n", __func__, ret);