xref: /linux/include/crypto/public_key.h (revision f7018c21350204c4cf628462f229d44d03545254)
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 <crypto/hash_info.h>
19 
20 enum pkey_algo {
21 	PKEY_ALGO_DSA,
22 	PKEY_ALGO_RSA,
23 	PKEY_ALGO__LAST
24 };
25 
26 extern const char *const pkey_algo_name[PKEY_ALGO__LAST];
27 extern const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST];
28 
29 /* asymmetric key implementation supports only up to SHA224 */
30 #define PKEY_HASH__LAST		(HASH_ALGO_SHA224 + 1)
31 
32 enum pkey_id_type {
33 	PKEY_ID_PGP,		/* OpenPGP generated key ID */
34 	PKEY_ID_X509,		/* X.509 arbitrary subjectKeyIdentifier */
35 	PKEY_ID_TYPE__LAST
36 };
37 
38 extern const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST];
39 
40 /*
41  * Cryptographic data for the public-key subtype of the asymmetric key type.
42  *
43  * Note that this may include private part of the key as well as the public
44  * part.
45  */
46 struct public_key {
47 	const struct public_key_algorithm *algo;
48 	u8	capabilities;
49 #define PKEY_CAN_ENCRYPT	0x01
50 #define PKEY_CAN_DECRYPT	0x02
51 #define PKEY_CAN_SIGN		0x04
52 #define PKEY_CAN_VERIFY		0x08
53 	enum pkey_algo pkey_algo : 8;
54 	enum pkey_id_type id_type : 8;
55 	union {
56 		MPI	mpi[5];
57 		struct {
58 			MPI	p;	/* DSA prime */
59 			MPI	q;	/* DSA group order */
60 			MPI	g;	/* DSA group generator */
61 			MPI	y;	/* DSA public-key value = g^x mod p */
62 			MPI	x;	/* DSA secret exponent (if present) */
63 		} dsa;
64 		struct {
65 			MPI	n;	/* RSA public modulus */
66 			MPI	e;	/* RSA public encryption exponent */
67 			MPI	d;	/* RSA secret encryption exponent (if present) */
68 			MPI	p;	/* RSA secret prime (if present) */
69 			MPI	q;	/* RSA secret prime (if present) */
70 		} rsa;
71 	};
72 };
73 
74 extern void public_key_destroy(void *payload);
75 
76 /*
77  * Public key cryptography signature data
78  */
79 struct public_key_signature {
80 	u8 *digest;
81 	u8 digest_size;			/* Number of bytes in digest */
82 	u8 nr_mpi;			/* Occupancy of mpi[] */
83 	enum pkey_algo pkey_algo : 8;
84 	enum hash_algo pkey_hash_algo : 8;
85 	union {
86 		MPI mpi[2];
87 		struct {
88 			MPI s;		/* m^d mod n */
89 		} rsa;
90 		struct {
91 			MPI r;
92 			MPI s;
93 		} dsa;
94 	};
95 };
96 
97 struct key;
98 extern int verify_signature(const struct key *key,
99 			    const struct public_key_signature *sig);
100 
101 #endif /* _LINUX_PUBLIC_KEY_H */
102