1/* Asymmetric Public-key cryptography key type interface
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#ifndef _KEYS_ASYMMETRIC_TYPE_H
15#define _KEYS_ASYMMETRIC_TYPE_H
16
17#include <linux/key-type.h>
18
19extern struct key_type key_type_asymmetric;
20
21/*
22 * Identifiers for an asymmetric key ID.  We have three ways of looking up a
23 * key derived from an X.509 certificate:
24 *
25 * (1) Serial Number & Issuer.  Non-optional.  This is the only valid way to
26 *     map a PKCS#7 signature to an X.509 certificate.
27 *
28 * (2) Issuer & Subject Unique IDs.  Optional.  These were the original way to
29 *     match X.509 certificates, but have fallen into disuse in favour of (3).
30 *
31 * (3) Auth & Subject Key Identifiers.  Optional.  SKIDs are only provided on
32 *     CA keys that are intended to sign other keys, so don't appear in end
33 *     user certificates unless forced.
34 *
35 * We could also support an PGP key identifier, which is just a SHA1 sum of the
36 * public key and certain parameters, but since we don't support PGP keys at
37 * the moment, we shall ignore those.
38 *
39 * What we actually do is provide a place where binary identifiers can be
40 * stashed and then compare against them when checking for an id match.
41 */
42struct asymmetric_key_id {
43	unsigned short	len;
44	unsigned char	data[];
45};
46
47struct asymmetric_key_ids {
48	void		*id[2];
49};
50
51extern bool asymmetric_key_id_same(const struct asymmetric_key_id *kid1,
52				   const struct asymmetric_key_id *kid2);
53
54extern bool asymmetric_key_id_partial(const struct asymmetric_key_id *kid1,
55				      const struct asymmetric_key_id *kid2);
56
57extern struct asymmetric_key_id *asymmetric_key_generate_id(const void *val_1,
58							    size_t len_1,
59							    const void *val_2,
60							    size_t len_2);
61
62/*
63 * The payload is at the discretion of the subtype.
64 */
65
66#endif /* _KEYS_ASYMMETRIC_TYPE_H */
67