xref: /linux/include/keys/asymmetric-type.h (revision cc04a46f11ea046ed53e2c832ae29e4790f7e35f)
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 
19 extern 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  */
42 struct asymmetric_key_id {
43 	unsigned short	len;
44 	unsigned char	data[];
45 };
46 
47 struct asymmetric_key_ids {
48 	void		*id[2];
49 };
50 
51 extern bool asymmetric_key_id_same(const struct asymmetric_key_id *kid1,
52 				   const struct asymmetric_key_id *kid2);
53 
54 extern bool asymmetric_key_id_partial(const struct asymmetric_key_id *kid1,
55 				      const struct asymmetric_key_id *kid2);
56 
57 extern 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