xref: /linux/include/crypto/public_key.h (revision 23b0f90ba871f096474e1c27c3d14f455189d2d9)
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  */
23 struct 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 
38 extern void public_key_free(struct public_key *key);
39 
40 /*
41  * Public key cryptography signature data
42  */
43 struct public_key_signature {
44 	struct asymmetric_key_id *auth_ids[3];
45 	u8 *s;			/* Signature */
46 	u8 *m;			/* Message data to pass to verifier */
47 	u32 s_size;		/* Number of bytes in signature */
48 	u32 m_size;		/* Number of bytes in ->m */
49 	bool m_free;		/* T if ->m needs freeing */
50 	bool algo_takes_data;	/* T if public key algo operates on data, not a hash */
51 	const char *pkey_algo;
52 	const char *hash_algo;
53 	const char *encoding;
54 };
55 
56 extern void public_key_signature_free(struct public_key_signature *sig);
57 
58 extern struct asymmetric_key_subtype public_key_subtype;
59 
60 struct key;
61 struct key_type;
62 union key_payload;
63 
64 extern int restrict_link_by_signature(struct key *dest_keyring,
65 				      const struct key_type *type,
66 				      const union key_payload *payload,
67 				      struct key *trust_keyring);
68 
69 extern int restrict_link_by_key_or_keyring(struct key *dest_keyring,
70 					   const struct key_type *type,
71 					   const union key_payload *payload,
72 					   struct key *trusted);
73 
74 extern int restrict_link_by_key_or_keyring_chain(struct key *trust_keyring,
75 						 const struct key_type *type,
76 						 const union key_payload *payload,
77 						 struct key *trusted);
78 
79 #if IS_REACHABLE(CONFIG_ASYMMETRIC_KEY_TYPE)
80 extern int restrict_link_by_ca(struct key *dest_keyring,
81 			       const struct key_type *type,
82 			       const union key_payload *payload,
83 			       struct key *trust_keyring);
84 int restrict_link_by_digsig(struct key *dest_keyring,
85 			    const struct key_type *type,
86 			    const union key_payload *payload,
87 			    struct key *trust_keyring);
88 #else
89 static inline int restrict_link_by_ca(struct key *dest_keyring,
90 				      const struct key_type *type,
91 				      const union key_payload *payload,
92 				      struct key *trust_keyring)
93 {
94 	return 0;
95 }
96 
97 static inline int restrict_link_by_digsig(struct key *dest_keyring,
98 					  const struct key_type *type,
99 					  const union key_payload *payload,
100 					  struct key *trust_keyring)
101 {
102 	return 0;
103 }
104 #endif
105 
106 extern int query_asymmetric_key(const struct kernel_pkey_params *,
107 				struct kernel_pkey_query *);
108 
109 extern int verify_signature(const struct key *,
110 			    const struct public_key_signature *);
111 
112 #if IS_REACHABLE(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE)
113 int public_key_verify_signature(const struct public_key *pkey,
114 				const struct public_key_signature *sig);
115 #else
116 static inline
117 int public_key_verify_signature(const struct public_key *pkey,
118 				const struct public_key_signature *sig)
119 {
120 	return -EINVAL;
121 }
122 #endif
123 
124 #endif /* _LINUX_PUBLIC_KEY_H */
125