Removed len argument from proposal_get_token()
[strongswan.git] / src / libstrongswan / crypto / signers / mac_signer.c
1 /*
2 * Copyright (C) 2012 Tobias Brunner
3 * Copyright (C) 2005-2008 Martin Willi
4 * Copyright (C) 2005 Jan Hutter
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
18 #include "mac_signer.h"
19
20 typedef struct private_signer_t private_signer_t;
21
22 /**
23 * Private data of a mac_signer_t object.
24 */
25 struct private_signer_t {
26
27 /**
28 * Public interface
29 */
30 signer_t public;
31
32 /**
33 * MAC to use
34 */
35 mac_t *mac;
36
37 /**
38 * Truncation of MAC output
39 */
40 size_t truncation;
41 };
42
43 METHOD(signer_t, get_signature, bool,
44 private_signer_t *this, chunk_t data, u_int8_t *buffer)
45 {
46 if (buffer)
47 {
48 u_int8_t mac[this->mac->get_mac_size(this->mac)];
49
50 if (!this->mac->get_mac(this->mac, data, mac))
51 {
52 return FALSE;
53 }
54 memcpy(buffer, mac, this->truncation);
55 return TRUE;
56 }
57 return this->mac->get_mac(this->mac, data, NULL);
58 }
59
60 METHOD(signer_t, allocate_signature, bool,
61 private_signer_t *this, chunk_t data, chunk_t *chunk)
62 {
63 if (chunk)
64 {
65 u_int8_t mac[this->mac->get_mac_size(this->mac)];
66
67 if (!this->mac->get_mac(this->mac, data, mac))
68 {
69 return FALSE;
70 }
71 *chunk = chunk_alloc(this->truncation);
72 memcpy(chunk->ptr, mac, this->truncation);
73 return TRUE;
74 }
75 return this->mac->get_mac(this->mac, data, NULL);
76 }
77
78 METHOD(signer_t, verify_signature, bool,
79 private_signer_t *this, chunk_t data, chunk_t signature)
80 {
81 u_int8_t mac[this->mac->get_mac_size(this->mac)];
82
83 if (signature.len != this->truncation)
84 {
85 return FALSE;
86 }
87 return this->mac->get_mac(this->mac, data, mac) &&
88 memeq(signature.ptr, mac, this->truncation);
89 }
90
91 METHOD(signer_t, get_key_size, size_t,
92 private_signer_t *this)
93 {
94 return this->mac->get_mac_size(this->mac);
95 }
96
97 METHOD(signer_t, get_block_size, size_t,
98 private_signer_t *this)
99 {
100 return this->truncation;
101 }
102
103 METHOD(signer_t, set_key, bool,
104 private_signer_t *this, chunk_t key)
105 {
106 return this->mac->set_key(this->mac, key);
107 }
108
109 METHOD(signer_t, destroy, void,
110 private_signer_t *this)
111 {
112 this->mac->destroy(this->mac);
113 free(this);
114 }
115
116 /*
117 * Described in header
118 */
119 signer_t *mac_signer_create(mac_t *mac, size_t len)
120 {
121 private_signer_t *this;
122
123 INIT(this,
124 .public = {
125 .get_signature = _get_signature,
126 .allocate_signature = _allocate_signature,
127 .verify_signature = _verify_signature,
128 .get_block_size = _get_block_size,
129 .get_key_size = _get_key_size,
130 .set_key = _set_key,
131 .destroy = _destroy,
132 },
133 .truncation = min(len, mac->get_mac_size(mac)),
134 .mac = mac,
135 );
136
137 return &this->public;
138 }
139