1 /* $OpenBSD: cbc128.c,v 1.5 2022/01/22 00:45:17 inoguchi Exp $ */
2 /* ====================================================================
3 * Copyright (c) 2008 The OpenSSL Project. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
15 * distribution.
16 *
17 * 3. All advertising materials mentioning features or use of this
18 * software must display the following acknowledgment:
19 * "This product includes software developed by the OpenSSL Project
20 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
21 *
22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23 * endorse or promote products derived from this software without
24 * prior written permission. For written permission, please contact
25 * openssl-core@openssl.org.
26 *
27 * 5. Products derived from this software may not be called "OpenSSL"
28 * nor may "OpenSSL" appear in their names without prior written
29 * permission of the OpenSSL Project.
30 *
31 * 6. Redistributions of any form whatsoever must retain the following
32 * acknowledgment:
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35 *
36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47 * OF THE POSSIBILITY OF SUCH DAMAGE.
48 * ====================================================================
49 *
50 */
51
52 #include <openssl/crypto.h>
53 #include "modes_lcl.h"
54 #include <string.h>
55
56 #ifndef MODES_DEBUG
57 # ifndef NDEBUG
58 # define NDEBUG
59 # endif
60 #endif
61
62 #undef STRICT_ALIGNMENT
63 #ifdef __STRICT_ALIGNMENT
64 #define STRICT_ALIGNMENT 1
65 #else
66 #define STRICT_ALIGNMENT 0
67 #endif
68
CRYPTO_cbc128_encrypt(const unsigned char * in,unsigned char * out,size_t len,const void * key,unsigned char ivec[16],block128_f block)69 void CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
70 size_t len, const void *key,
71 unsigned char ivec[16], block128_f block)
72 {
73 size_t n;
74 const unsigned char *iv = ivec;
75
76 #if !defined(OPENSSL_SMALL_FOOTPRINT)
77 if (STRICT_ALIGNMENT &&
78 ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
79 while (len>=16) {
80 for(n=0; n<16; ++n)
81 out[n] = in[n] ^ iv[n];
82 (*block)(out, out, key);
83 iv = out;
84 len -= 16;
85 in += 16;
86 out += 16;
87 }
88 } else {
89 while (len>=16) {
90 for(n=0; n<16; n+=sizeof(size_t))
91 *(size_t*)(out+n) =
92 *(size_t*)(in+n) ^ *(size_t*)(iv+n);
93 (*block)(out, out, key);
94 iv = out;
95 len -= 16;
96 in += 16;
97 out += 16;
98 }
99 }
100 #endif
101 while (len) {
102 for(n=0; n<16 && n<len; ++n)
103 out[n] = in[n] ^ iv[n];
104 for(; n<16; ++n)
105 out[n] = iv[n];
106 (*block)(out, out, key);
107 iv = out;
108 if (len<=16) break;
109 len -= 16;
110 in += 16;
111 out += 16;
112 }
113 memmove(ivec,iv,16);
114 }
115
CRYPTO_cbc128_decrypt(const unsigned char * in,unsigned char * out,size_t len,const void * key,unsigned char ivec[16],block128_f block)116 void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
117 size_t len, const void *key,
118 unsigned char ivec[16], block128_f block)
119 {
120 size_t n;
121 union { size_t t[16/sizeof(size_t)]; unsigned char c[16]; } tmp;
122
123 #if !defined(OPENSSL_SMALL_FOOTPRINT)
124 if (in != out) {
125 const unsigned char *iv = ivec;
126
127 if (STRICT_ALIGNMENT &&
128 ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
129 while (len>=16) {
130 (*block)(in, out, key);
131 for(n=0; n<16; ++n)
132 out[n] ^= iv[n];
133 iv = in;
134 len -= 16;
135 in += 16;
136 out += 16;
137 }
138 } else if (16%sizeof(size_t) == 0) { /* always true */
139 while (len>=16) {
140 size_t *out_t=(size_t *)out, *iv_t=(size_t *)iv;
141
142 (*block)(in, out, key);
143 for(n=0; n<16/sizeof(size_t); n++)
144 out_t[n] ^= iv_t[n];
145 iv = in;
146 len -= 16;
147 in += 16;
148 out += 16;
149 }
150 }
151 memmove(ivec,iv,16);
152 } else {
153 if (STRICT_ALIGNMENT &&
154 ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
155 unsigned char c;
156 while (len>=16) {
157 (*block)(in, tmp.c, key);
158 for(n=0; n<16; ++n) {
159 c = in[n];
160 out[n] = tmp.c[n] ^ ivec[n];
161 ivec[n] = c;
162 }
163 len -= 16;
164 in += 16;
165 out += 16;
166 }
167 } else if (16%sizeof(size_t) == 0) { /* always true */
168 while (len>=16) {
169 size_t c, *out_t=(size_t *)out, *ivec_t=(size_t *)ivec;
170 const size_t *in_t=(const size_t *)in;
171
172 (*block)(in, tmp.c, key);
173 for(n=0; n<16/sizeof(size_t); n++) {
174 c = in_t[n];
175 out_t[n] = tmp.t[n] ^ ivec_t[n];
176 ivec_t[n] = c;
177 }
178 len -= 16;
179 in += 16;
180 out += 16;
181 }
182 }
183 }
184 #endif
185 while (len) {
186 unsigned char c;
187 (*block)(in, tmp.c, key);
188 for(n=0; n<16 && n<len; ++n) {
189 c = in[n];
190 out[n] = tmp.c[n] ^ ivec[n];
191 ivec[n] = c;
192 }
193 if (len<=16) {
194 for (; n<16; ++n)
195 ivec[n] = in[n];
196 break;
197 }
198 len -= 16;
199 in += 16;
200 out += 16;
201 }
202 }
203