xref: /linux/include/crypto/public_key.h (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
1 /* Asymmetric public-key algorithm definitions
2  *
3  * See Documentation/crypto/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 _LINUX_PUBLIC_KEY_H
15 #define _LINUX_PUBLIC_KEY_H
16 
17 #include <linux/mpi.h>
18 #include <keys/asymmetric-type.h>
19 #include <crypto/hash_info.h>
20 
21 enum pkey_algo {
22 	PKEY_ALGO_DSA,
23 	PKEY_ALGO_RSA,
24 	PKEY_ALGO__LAST
25 };
26 
27 extern const char *const pkey_algo_name[PKEY_ALGO__LAST];
28 extern const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST];
29 
30 /* asymmetric key implementation supports only up to SHA224 */
31 #define PKEY_HASH__LAST		(HASH_ALGO_SHA224 + 1)
32 
33 enum pkey_id_type {
34 	PKEY_ID_PGP,		/* OpenPGP generated key ID */
35 	PKEY_ID_X509,		/* X.509 arbitrary subjectKeyIdentifier */
36 	PKEY_ID_TYPE__LAST
37 };
38 
39 extern const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST];
40 
41 /*
42  * Cryptographic data for the public-key subtype of the asymmetric key type.
43  *
44  * Note that this may include private part of the key as well as the public
45  * part.
46  */
47 struct public_key {
48 	const struct public_key_algorithm *algo;
49 	u8	capabilities;
50 #define PKEY_CAN_ENCRYPT	0x01
51 #define PKEY_CAN_DECRYPT	0x02
52 #define PKEY_CAN_SIGN		0x04
53 #define PKEY_CAN_VERIFY		0x08
54 	enum pkey_algo pkey_algo : 8;
55 	enum pkey_id_type id_type : 8;
56 	union {
57 		MPI	mpi[5];
58 		struct {
59 			MPI	p;	/* DSA prime */
60 			MPI	q;	/* DSA group order */
61 			MPI	g;	/* DSA group generator */
62 			MPI	y;	/* DSA public-key value = g^x mod p */
63 			MPI	x;	/* DSA secret exponent (if present) */
64 		} dsa;
65 		struct {
66 			MPI	n;	/* RSA public modulus */
67 			MPI	e;	/* RSA public encryption exponent */
68 			MPI	d;	/* RSA secret encryption exponent (if present) */
69 			MPI	p;	/* RSA secret prime (if present) */
70 			MPI	q;	/* RSA secret prime (if present) */
71 		} rsa;
72 	};
73 };
74 
75 extern void public_key_destroy(void *payload);
76 
77 /*
78  * Public key cryptography signature data
79  */
80 struct public_key_signature {
81 	u8 *digest;
82 	u8 digest_size;			/* Number of bytes in digest */
83 	u8 nr_mpi;			/* Occupancy of mpi[] */
84 	enum pkey_algo pkey_algo : 8;
85 	enum hash_algo pkey_hash_algo : 8;
86 	union {
87 		MPI mpi[2];
88 		struct {
89 			MPI s;		/* m^d mod n */
90 		} rsa;
91 		struct {
92 			MPI r;
93 			MPI s;
94 		} dsa;
95 	};
96 };
97 
98 struct key;
99 extern int verify_signature(const struct key *key,
100 			    const struct public_key_signature *sig);
101 
102 struct asymmetric_key_id;
103 extern struct key *x509_request_asymmetric_key(struct key *keyring,
104 					       const struct asymmetric_key_id *kid,
105 					       bool partial);
106 
107 #endif /* _LINUX_PUBLIC_KEY_H */
108