Variable key length crypters use default key length if zero given
[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 typedef struct private_blowfish_crypter_t private_blowfish_crypter_t;
68
69 /**
70 * Class implementing the Blowfish symmetric encryption algorithm.
71 */
72 struct private_blowfish_crypter_t {
73
74 /**
75 * Public part of this class.
76 */
77 blowfish_crypter_t public;
78
79 /**
80 * Blowfish key schedule
81 */
82 BF_KEY schedule;
83
84 /**
85 * Key size of this Blowfish cipher object.
86 */
87 u_int32_t key_size;
88 };
89
90 METHOD(crypter_t, decrypt, void,
91 private_blowfish_crypter_t *this, chunk_t data, chunk_t iv,
92 chunk_t *decrypted)
93 {
94 u_int8_t *in, *out;
95
96 if (decrypted)
97 {
98 *decrypted = chunk_alloc(data.len);
99 out = decrypted->ptr;
100 }
101 else
102 {
103 out = data.ptr;
104 }
105 in = data.ptr;
106 iv = chunk_clone(iv);
107
108 BF_cbc_encrypt(in, out, data.len, &this->schedule, iv.ptr, 0);
109
110 free(iv.ptr);
111 }
112
113 METHOD(crypter_t, encrypt, void,
114 private_blowfish_crypter_t *this, chunk_t data, chunk_t iv,
115 chunk_t *encrypted)
116 {
117 u_int8_t *in, *out;
118
119 if (encrypted)
120 {
121 *encrypted = chunk_alloc(data.len);
122 out = encrypted->ptr;
123 }
124 else
125 {
126 out = data.ptr;
127 }
128 in = data.ptr;
129 iv = chunk_clone(iv);
130
131 BF_cbc_encrypt(in, out, data.len, &this->schedule, iv.ptr, 1);
132
133 free(iv.ptr);
134 }
135
136 METHOD(crypter_t, get_block_size, size_t,
137 private_blowfish_crypter_t *this)
138 {
139 return BLOWFISH_BLOCK_SIZE;
140 }
141
142 METHOD(crypter_t, get_iv_size, size_t,
143 private_blowfish_crypter_t *this)
144 {
145 return BLOWFISH_BLOCK_SIZE;
146 }
147
148 METHOD(crypter_t, get_key_size, size_t,
149 private_blowfish_crypter_t *this)
150 {
151 return this->key_size;
152 }
153
154 METHOD(crypter_t, set_key, void,
155 private_blowfish_crypter_t *this, chunk_t key)
156 {
157 BF_set_key(&this->schedule, key.len , key.ptr);
158 }
159
160 METHOD(crypter_t, destroy, void,
161 private_blowfish_crypter_t *this)
162 {
163 free(this);
164 }
165
166 /*
167 * Described in header
168 */
169 blowfish_crypter_t *blowfish_crypter_create(encryption_algorithm_t algo,
170 size_t key_size)
171 {
172 private_blowfish_crypter_t *this;
173
174 if (algo != ENCR_BLOWFISH)
175 {
176 return NULL;
177 }
178
179 INIT(this,
180 .public.crypter = {
181 .encrypt = _encrypt,
182 .decrypt = _decrypt,
183 .get_block_size = _get_block_size,
184 .get_iv_size = _get_iv_size,
185 .get_key_size = _get_key_size,
186 .set_key = _set_key,
187 .destroy = _destroy,
188 },
189 .key_size = key_size ?: 16,
190 );
191
192 return &this->public;
193 }