14363dde6660aa1f94b72d33bb62f8ae0a9ec47e
[strongswan.git] / src / libstrongswan / crypto / hashers / hasher.h
1 /*
2 * Copyright (C) 2005 Jan Hutter
3 * Copyright (C) 2005-2006 Martin Willi
4 *
5 * Hochschule fuer Technik Rapperswil
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * for more details.
16 *
17 * $Id$
18 */
19
20 /**
21 * @defgroup traffic_selector traffic_selector
22 * @{ @ingroup config
23 */
24
25 #ifndef HASHER_H_
26 #define HASHER_H_
27
28 typedef enum hash_algorithm_t hash_algorithm_t;
29 typedef struct hasher_t hasher_t;
30
31 #include <library.h>
32
33 /**
34 * Algorithms to use for hashing.
35 */
36 enum hash_algorithm_t {
37 /** not specified hash function */
38 HASH_UNKNOWN = 0,
39 /** preferred hash function, general purpose */
40 HASH_PREFERRED = 1,
41 HASH_MD2 = 2,
42 HASH_MD5 = 3,
43 HASH_SHA1 = 4,
44 HASH_SHA256 = 5,
45 HASH_SHA384 = 6,
46 HASH_SHA512 = 7,
47 HASH_MD4 = 8,
48 };
49
50 #define HASH_SIZE_MD2 16
51 #define HASH_SIZE_MD4 16
52 #define HASH_SIZE_MD5 16
53 #define HASH_SIZE_SHA1 20
54 #define HASH_SIZE_SHA256 32
55 #define HASH_SIZE_SHA384 48
56 #define HASH_SIZE_SHA512 64
57
58 /**
59 * enum names for hash_algorithm_t.
60 */
61 extern enum_name_t *hash_algorithm_names;
62
63 /**
64 * Generic interface for all hash functions.
65 */
66 struct hasher_t {
67 /**
68 * Hash data and write it in the buffer.
69 *
70 * If the parameter hash is NULL, no result is written back
71 * and more data can be appended to already hashed data.
72 * If not, the result is written back and the hasher is reset.
73 *
74 * The hash output parameter must hold at least
75 * hash_t.get_block_size() bytes.
76 *
77 * @param data data to hash
78 * @param hash pointer where the hash will be written
79 */
80 void (*get_hash) (hasher_t *this, chunk_t data, u_int8_t *hash);
81
82 /**
83 * Hash data and allocate space for the hash.
84 *
85 * If the parameter hash is NULL, no result is written back
86 * and more data can be appended to already hashed data.
87 * If not, the result is written back and the hasher is reset.
88 *
89 * @param data chunk with data to hash
90 * @param hash chunk which will hold allocated hash
91 */
92 void (*allocate_hash) (hasher_t *this, chunk_t data, chunk_t *hash);
93
94 /**
95 * Get the size of the resulting hash.
96 *
97 * @return hash size in bytes
98 */
99 size_t (*get_hash_size) (hasher_t *this);
100
101 /**
102 * Resets the hashers state.
103 */
104 void (*reset) (hasher_t *this);
105
106 /**
107 * Destroys a hasher object.
108 */
109 void (*destroy) (hasher_t *this);
110 };
111
112 /**
113 * Conversion of ASN.1 OID to hash algorithm.
114 *
115 * @param oid ASN.1 OID
116 * @return hash algorithm, HASH_UNKNOWN if OID unsuported
117 */
118 hash_algorithm_t hasher_algorithm_from_oid(int oid);
119
120 /**
121 * Conversion of hash algorithm into ASN.1 OID.
122 *
123 * @param alg hash algorithm
124 * @return ASN.1 OID, or OID_UNKNOW
125 */
126 int hasher_algorithm_to_oid(hash_algorithm_t alg);
127
128 /**
129 * Conversion of hash signature algorithm into ASN.1 OID.
130 *
131 * @param alg hash algorithm
132 * @return ASN.1 OID if, or OID_UNKNOW
133 */
134 int hasher_signature_algorithm_to_oid(hash_algorithm_t alg);
135
136 #endif /** HASHER_H_ @}*/