1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/* Asymmetric public-key algorithm definitions
3 *
4 * See Documentation/crypto/asymmetric-keys.rst
5 *
6 * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
7 * Written by David Howells (dhowells@redhat.com)
8 */
9
10#ifndef _LINUX_PUBLIC_KEY_H
11#define _LINUX_PUBLIC_KEY_H
12
13#include <linux/errno.h>
14#include <linux/keyctl.h>
15#include <linux/oid_registry.h>
16
17/*
18 * Cryptographic data for the public-key subtype of the asymmetric key type.
19 *
20 * Note that this may include private part of the key as well as the public
21 * part.
22 */
23struct public_key {
24 void *key;
25 u32 keylen;
26 enum OID algo;
27 void *params;
28 u32 paramlen;
29 bool key_is_private;
30 const char *id_type;
31 const char *pkey_algo;
32 unsigned long key_eflags; /* key extension flags */
33#define KEY_EFLAG_CA 0 /* set if the CA basic constraints is set */
34#define KEY_EFLAG_DIGITALSIG 1 /* set if the digitalSignature usage is set */
35#define KEY_EFLAG_KEYCERTSIGN 2 /* set if the keyCertSign usage is set */
36};
37
38extern void public_key_free(struct public_key *key);
39
40/*
41 * Public key cryptography signature data
42 */
43struct public_key_signature {
44 struct asymmetric_key_id *auth_ids[3];
45 u8 *s; /* Signature */
46 u8 *digest;
47 u32 s_size; /* Number of bytes in signature */
48 u32 digest_size; /* Number of bytes in digest */
49 const char *pkey_algo;
50 const char *hash_algo;
51 const char *encoding;
52};
53
54extern void public_key_signature_free(struct public_key_signature *sig);
55
56extern struct asymmetric_key_subtype public_key_subtype;
57
58struct key;
59struct key_type;
60union key_payload;
61
62extern int restrict_link_by_signature(struct key *dest_keyring,
63 const struct key_type *type,
64 const union key_payload *payload,
65 struct key *trust_keyring);
66
67extern int restrict_link_by_key_or_keyring(struct key *dest_keyring,
68 const struct key_type *type,
69 const union key_payload *payload,
70 struct key *trusted);
71
72extern int restrict_link_by_key_or_keyring_chain(struct key *trust_keyring,
73 const struct key_type *type,
74 const union key_payload *payload,
75 struct key *trusted);
76
77#if IS_REACHABLE(CONFIG_ASYMMETRIC_KEY_TYPE)
78extern int restrict_link_by_ca(struct key *dest_keyring,
79 const struct key_type *type,
80 const union key_payload *payload,
81 struct key *trust_keyring);
82int restrict_link_by_digsig(struct key *dest_keyring,
83 const struct key_type *type,
84 const union key_payload *payload,
85 struct key *trust_keyring);
86#else
87static inline int restrict_link_by_ca(struct key *dest_keyring,
88 const struct key_type *type,
89 const union key_payload *payload,
90 struct key *trust_keyring)
91{
92 return 0;
93}
94
95static inline int restrict_link_by_digsig(struct key *dest_keyring,
96 const struct key_type *type,
97 const union key_payload *payload,
98 struct key *trust_keyring)
99{
100 return 0;
101}
102#endif
103
104extern int query_asymmetric_key(const struct kernel_pkey_params *,
105 struct kernel_pkey_query *);
106
107extern int verify_signature(const struct key *,
108 const struct public_key_signature *);
109
110#if IS_REACHABLE(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE)
111int public_key_verify_signature(const struct public_key *pkey,
112 const struct public_key_signature *sig);
113#else
114static inline
115int public_key_verify_signature(const struct public_key *pkey,
116 const struct public_key_signature *sig)
117{
118 return -EINVAL;
119}
120#endif
121
122#endif /* _LINUX_PUBLIC_KEY_H */
123