blob: 50b3f880b4ff0d761fa29bfc9d58344235e42c31 [file] [log] [blame]
David Howells4ae71c12012-09-21 23:25:04 +01001/* Signature verification with an asymmetric key
2 *
3 * See Documentation/security/asymmetric-keys.txt
4 *
5 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
6 * Written by David Howells (dhowells@redhat.com)
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public Licence
10 * as published by the Free Software Foundation; either version
11 * 2 of the Licence, or (at your option) any later version.
12 */
13
14#include <keys/asymmetric-subtype.h>
15#include <linux/module.h>
16#include <linux/err.h>
17#include <crypto/public_key.h>
18#include "asymmetric_keys.h"
19
20/**
21 * verify_signature - Initiate the use of an asymmetric key to verify a signature
22 * @key: The asymmetric key to verify against
23 * @sig: The signature to check
24 *
25 * Returns 0 if successful or else an error.
26 */
27int verify_signature(const struct key *key,
28 const struct public_key_signature *sig)
29{
30 const struct asymmetric_key_subtype *subtype;
31 int ret;
32
33 pr_devel("==>%s()\n", __func__);
34
35 if (key->type != &key_type_asymmetric)
36 return -EINVAL;
37 subtype = asymmetric_key_subtype(key);
38 if (!subtype ||
39 !key->payload.data)
40 return -EINVAL;
41 if (!subtype->verify_signature)
42 return -ENOTSUPP;
43
44 ret = subtype->verify_signature(key, sig);
45
46 pr_devel("<==%s() = %d\n", __func__, ret);
47 return ret;
48}
49EXPORT_SYMBOL_GPL(verify_signature);