0e54f75470b2fbba3b85289ec845b9e7bfb8ec4e
[openssl.git] / crypto / modes / cbc128.c
1 /* ====================================================================
2  * Copyright (c) 2008 The OpenSSL Project.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer. 
10  *
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in
13  *    the documentation and/or other materials provided with the
14  *    distribution.
15  *
16  * 3. All advertising materials mentioning features or use of this
17  *    software must display the following acknowledgment:
18  *    "This product includes software developed by the OpenSSL Project
19  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
20  *
21  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
22  *    endorse or promote products derived from this software without
23  *    prior written permission. For written permission, please contact
24  *    openssl-core@openssl.org.
25  *
26  * 5. Products derived from this software may not be called "OpenSSL"
27  *    nor may "OpenSSL" appear in their names without prior written
28  *    permission of the OpenSSL Project.
29  *
30  * 6. Redistributions of any form whatsoever must retain the following
31  *    acknowledgment:
32  *    "This product includes software developed by the OpenSSL Project
33  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
34  *
35  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
36  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
37  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
38  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
39  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
41  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
42  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
44  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
45  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
46  * OF THE POSSIBILITY OF SUCH DAMAGE.
47  * ====================================================================
48  *
49  */
50
51 #include <openssl/crypto.h>
52 #include "modes_lcl.h"
53 #include <string.h>
54
55 #ifndef MODES_DEBUG
56 # ifndef NDEBUG
57 #  define NDEBUG
58 # endif
59 #endif
60 #include <assert.h>
61
62 #ifndef STRICT_ALIGNMENT
63 #  define STRICT_ALIGNMENT 0
64 #endif
65
66 void CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
67                         size_t len, const void *key,
68                         unsigned char ivec[16], block128_f block)
69 {
70         size_t n;
71         const unsigned char *iv = ivec;
72
73         assert(in && out && key && ivec);
74
75 #if !defined(OPENSSL_SMALL_FOOTPRINT)
76         if (STRICT_ALIGNMENT &&
77             ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
78                 while (len>=16) {
79                         for(n=0; n<16; ++n)
80                                 out[n] = in[n] ^ iv[n];
81                         (*block)(out, out, key);
82                         iv = out;
83                         len -= 16;
84                         in  += 16;
85                         out += 16;
86                 }
87         } else {
88                 while (len>=16) {
89                         for(n=0; n<16; n+=sizeof(size_t))
90                                 *(size_t*)(out+n) =
91                                 *(size_t*)(in+n) ^ *(size_t*)(iv+n);
92                         (*block)(out, out, key);
93                         iv = out;
94                         len -= 16;
95                         in  += 16;
96                         out += 16;
97                 }
98         }
99 #endif
100         while (len) {
101                 for(n=0; n<16 && n<len; ++n)
102                         out[n] = in[n] ^ iv[n];
103                 for(; n<16; ++n)
104                         out[n] = iv[n];
105                 (*block)(out, out, key);
106                 iv = out;
107                 if (len<=16) break;
108                 len -= 16;
109                 in  += 16;
110                 out += 16;
111         }
112         memcpy(ivec,iv,16);
113 }
114
115 void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
116                         size_t len, const void *key,
117                         unsigned char ivec[16], block128_f block)
118 {
119         size_t n;
120         union { size_t t[16/sizeof(size_t)]; unsigned char c[16]; } tmp;
121
122         assert(in && out && key && ivec);
123
124 #if !defined(OPENSSL_SMALL_FOOTPRINT)
125         if (in != out) {
126                 const unsigned char *iv = ivec;
127
128                 if (STRICT_ALIGNMENT &&
129                     ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
130                         while (len>=16) {
131                                 (*block)(in, out, key);
132                                 for(n=0; n<16; ++n)
133                                         out[n] ^= iv[n];
134                                 iv = in;
135                                 len -= 16;
136                                 in  += 16;
137                                 out += 16;
138                         }
139                 }
140                 else  if (16%sizeof(size_t) == 0) { /* always true */
141                         while (len>=16) {
142                                 size_t *out_t=(size_t *)out, *iv_t=(size_t *)iv;
143
144                                 (*block)(in, out, key);
145                                 for(n=0; n<16/sizeof(size_t); n++)
146                                         out_t[n] ^= iv_t[n];
147                                 iv = in;
148                                 len -= 16;
149                                 in  += 16;
150                                 out += 16;
151                         }
152                 }
153                 memcpy(ivec,iv,16);
154         } else {
155                 if (STRICT_ALIGNMENT &&
156                     ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
157                         unsigned char c;
158                         while (len>=16) {
159                                 (*block)(in, tmp.c, key);
160                                 for(n=0; n<16; ++n) {
161                                         c = in[n];
162                                         out[n] = tmp.c[n] ^ ivec[n];
163                                         ivec[n] = c;
164                                 }
165                                 len -= 16;
166                                 in  += 16;
167                                 out += 16;
168                         }
169                 }
170                 else if (16%sizeof(size_t) == 0) { /* always true */
171                         while (len>=16) {
172                                 size_t c, *out_t=(size_t *)out, *ivec_t=(size_t *)ivec;
173                                 const size_t *in_t=(const size_t *)in;
174
175                                 (*block)(in, tmp.c, key);
176                                 for(n=0; n<16/sizeof(size_t); n++) {
177                                         c = in_t[n];
178                                         out_t[n] = tmp.t[n] ^ ivec_t[n];
179                                         ivec_t[n] = c;
180                                 }
181                                 len -= 16;
182                                 in  += 16;
183                                 out += 16;
184                         }
185                 }
186         }
187 #endif
188         while (len) {
189                 unsigned char c;
190                 (*block)(in, tmp.c, key);
191                 for(n=0; n<16 && n<len; ++n) {
192                         c = in[n];
193                         out[n] = tmp.c[n] ^ ivec[n];
194                         ivec[n] = c;
195                 }
196                 if (len<=16) {
197                         for (; n<16; ++n)
198                                 ivec[n] = in[n];
199                         break;
200                 }
201                 len -= 16;
202                 in  += 16;
203                 out += 16;
204         }
205 }