clone iv before blowfish en|decryption
[strongswan.git] / src / libstrongswan / plugins / blowfish / blowfish_crypter.c
1 /*
2 * Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 *
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
7 *
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to. The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14 *
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 * must display the following acknowledgement:
32 * "This product includes cryptographic software written by
33 * Eric Young (eay@cryptsoft.com)"
34 * The word 'cryptographic' can be left out if the rouines from the library
35 * being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 * the apps directory (application code) you must include an acknowledgement:
38 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 *
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed. i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.]
56 */
57
58 #include "blowfish.h"
59
60 /* Blowfish as implemented from 'Blowfish: Springer-Verlag paper'
61 * (From LECTURE NOTES IN COMPUTER SCIENCE 809, FAST SOFTWARE ENCRYPTION,
62 * CAMBRIDGE SECURITY WORKSHOP, CAMBRIDGE, U.K., DECEMBER 9-11, 1993)
63 */
64
65 #include "blowfish_crypter.h"
66
67 #define BLOWFISH_BLOCK_SIZE 8
68
69 typedef struct private_blowfish_crypter_t private_blowfish_crypter_t;
70
71 /**
72 * Class implementing the Blowfish symmetric encryption algorithm.
73 *
74 * @ingroup crypters
75 */
76 struct private_blowfish_crypter_t {
77
78 /**
79 * Public part of this class.
80 */
81 blowfish_crypter_t public;
82
83 /**
84 * Blowfish key schedule
85 */
86 BF_KEY schedule;
87
88 /**
89 * Key size of this Blowfish cipher object.
90 */
91 u_int32_t key_size;
92 };
93
94 /**
95 * Implementation of crypter_t.decrypt.
96 */
97 static void decrypt(private_blowfish_crypter_t *this, chunk_t data, chunk_t iv,
98 chunk_t *decrypted)
99 {
100 u_int8_t *in, *out;
101
102 if (decrypted)
103 {
104 *decrypted = chunk_alloc(data.len);
105 out = decrypted->ptr;
106 }
107 else
108 {
109 out = data.ptr;
110 }
111 in = data.ptr;
112 iv = chunk_clone(iv);
113
114 BF_cbc_encrypt(in, out, data.len, &this->schedule, iv.ptr, 0);
115
116 free(iv.ptr);
117 }
118
119 /**
120 * Implementation of crypter_t.decrypt.
121 */
122 static void encrypt (private_blowfish_crypter_t *this, chunk_t data, chunk_t iv,
123 chunk_t *encrypted)
124 {
125 u_int8_t *in, *out;
126
127 if (encrypted)
128 {
129 *encrypted = chunk_alloc(data.len);
130 out = encrypted->ptr;
131 }
132 else
133 {
134 out = data.ptr;
135 }
136 in = data.ptr;
137 iv = chunk_clone(iv);
138
139 BF_cbc_encrypt(in, out, data.len, &this->schedule, iv.ptr, 1);
140
141 free(iv.ptr);
142 }
143
144 /**
145 * Implementation of crypter_t.get_block_size.
146 */
147 static size_t get_block_size (private_blowfish_crypter_t *this)
148 {
149 return BLOWFISH_BLOCK_SIZE;
150 }
151
152 /**
153 * Implementation of crypter_t.get_key_size.
154 */
155 static size_t get_key_size (private_blowfish_crypter_t *this)
156 {
157 return this->key_size;
158 }
159
160 /**
161 * Implementation of crypter_t.set_key.
162 */
163 static void set_key (private_blowfish_crypter_t *this, chunk_t key)
164 {
165 BF_set_key(&this->schedule, key.len , key.ptr);
166 }
167
168 /**
169 * Implementation of crypter_t.destroy and blowfish_crypter_t.destroy.
170 */
171 static void destroy (private_blowfish_crypter_t *this)
172 {
173 free(this);
174 }
175
176 /*
177 * Described in header
178 */
179 blowfish_crypter_t *blowfish_crypter_create(encryption_algorithm_t algo, size_t key_size)
180 {
181 private_blowfish_crypter_t *this;
182
183 if (algo != ENCR_BLOWFISH)
184 {
185 return NULL;
186 }
187
188 this = malloc_thing(private_blowfish_crypter_t);
189
190 this->key_size = key_size;
191 this->public.crypter_interface.encrypt = (void (*) (crypter_t *, chunk_t,chunk_t, chunk_t *)) encrypt;
192 this->public.crypter_interface.decrypt = (void (*) (crypter_t *, chunk_t , chunk_t, chunk_t *)) decrypt;
193 this->public.crypter_interface.get_block_size = (size_t (*) (crypter_t *)) get_block_size;
194 this->public.crypter_interface.get_key_size = (size_t (*) (crypter_t *)) get_key_size;
195 this->public.crypter_interface.set_key = (void (*) (crypter_t *,chunk_t)) set_key;
196 this->public.crypter_interface.destroy = (void (*) (crypter_t *)) destroy;
197
198 return &(this->public);
199 }