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 #include <assert.h>
50 #include <string.h>
51
52 #include <openssl/type_check.h>
53
54 #include "internal.h"
55 #include "../../internal.h"
56
57
CRYPTO_cbc128_encrypt(const uint8_t * in,uint8_t * out,size_t len,const AES_KEY * key,uint8_t ivec[16],block128_f block)58 void CRYPTO_cbc128_encrypt(const uint8_t *in, uint8_t *out, size_t len,
59 const AES_KEY *key, uint8_t ivec[16],
60 block128_f block) {
61 assert(key != NULL && ivec != NULL);
62 if (len == 0) {
63 // Avoid |ivec| == |iv| in the |memcpy| below, which is not legal in C.
64 return;
65 }
66
67 assert(in != NULL && out != NULL);
68 size_t n;
69 const uint8_t *iv = ivec;
70 while (len >= 16) {
71 for (n = 0; n < 16; n += sizeof(crypto_word_t)) {
72 CRYPTO_store_word_le(
73 out + n, CRYPTO_load_word_le(in + n) ^ CRYPTO_load_word_le(iv + n));
74 }
75 (*block)(out, out, key);
76 iv = out;
77 len -= 16;
78 in += 16;
79 out += 16;
80 }
81
82 while (len) {
83 for (n = 0; n < 16 && n < len; ++n) {
84 out[n] = in[n] ^ iv[n];
85 }
86 for (; n < 16; ++n) {
87 out[n] = iv[n];
88 }
89 (*block)(out, out, key);
90 iv = out;
91 if (len <= 16) {
92 break;
93 }
94 len -= 16;
95 in += 16;
96 out += 16;
97 }
98
99 OPENSSL_memcpy(ivec, iv, 16);
100 }
101
CRYPTO_cbc128_decrypt(const uint8_t * in,uint8_t * out,size_t len,const AES_KEY * key,uint8_t ivec[16],block128_f block)102 void CRYPTO_cbc128_decrypt(const uint8_t *in, uint8_t *out, size_t len,
103 const AES_KEY *key, uint8_t ivec[16],
104 block128_f block) {
105 assert(key != NULL && ivec != NULL);
106 if (len == 0) {
107 // Avoid |ivec| == |iv| in the |memcpy| below, which is not legal in C.
108 return;
109 }
110
111 assert(in != NULL && out != NULL);
112
113 const uintptr_t inptr = (uintptr_t) in;
114 const uintptr_t outptr = (uintptr_t) out;
115 // If |in| and |out| alias, |in| must be ahead.
116 assert(inptr >= outptr || inptr + len <= outptr);
117
118 size_t n;
119 union {
120 crypto_word_t t[16 / sizeof(crypto_word_t)];
121 uint8_t c[16];
122 } tmp;
123
124 if ((inptr >= 32 && outptr <= inptr - 32) || inptr < outptr) {
125 // If |out| is at least two blocks behind |in| or completely disjoint, there
126 // is no need to decrypt to a temporary block.
127 OPENSSL_STATIC_ASSERT(16 % sizeof(crypto_word_t) == 0,
128 "block cannot be evenly divided into words");
129 const uint8_t *iv = ivec;
130 while (len >= 16) {
131 (*block)(in, out, key);
132 for (n = 0; n < 16; n += sizeof(crypto_word_t)) {
133 CRYPTO_store_word_le(out + n, CRYPTO_load_word_le(out + n) ^
134 CRYPTO_load_word_le(iv + n));
135 }
136 iv = in;
137 len -= 16;
138 in += 16;
139 out += 16;
140 }
141 OPENSSL_memcpy(ivec, iv, 16);
142 } else {
143 OPENSSL_STATIC_ASSERT(16 % sizeof(crypto_word_t) == 0,
144 "block cannot be evenly divided into words");
145
146 while (len >= 16) {
147 (*block)(in, tmp.c, key);
148 for (n = 0; n < 16; n += sizeof(crypto_word_t)) {
149 crypto_word_t c = CRYPTO_load_word_le(in + n);
150 CRYPTO_store_word_le(out + n, tmp.t[n / sizeof(crypto_word_t)] ^
151 CRYPTO_load_word_le(ivec + n));
152 CRYPTO_store_word_le(ivec + n, c);
153 }
154 len -= 16;
155 in += 16;
156 out += 16;
157 }
158 }
159
160 while (len) {
161 uint8_t c;
162 (*block)(in, tmp.c, key);
163 for (n = 0; n < 16 && n < len; ++n) {
164 c = in[n];
165 out[n] = tmp.c[n] ^ ivec[n];
166 ivec[n] = c;
167 }
168 if (len <= 16) {
169 for (; n < 16; ++n) {
170 ivec[n] = in[n];
171 }
172 break;
173 }
174 len -= 16;
175 in += 16;
176 out += 16;
177 }
178 }
179