1 /* crypto/aes/aes_cbc.c -*- mode:C; c-file-style: "eay" -*- */
2 /* ====================================================================
3 * Copyright (c) 1998-2002 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 #ifndef AES_DEBUG
53 # ifndef NDEBUG
54 # define NDEBUG
55 # endif
56 #endif
57 #include <assert.h>
58
59 #include <openssl/aes.h>
60 #include "aes_locl.h"
61
AES_cbc_encrypt(const unsigned char * in,unsigned char * out,const unsigned long length,const AES_KEY * key,unsigned char * ivec,const int enc)62 void AES_cbc_encrypt(const unsigned char *in, unsigned char *out,
63 const unsigned long length, const AES_KEY *key,
64 unsigned char *ivec, const int enc) {
65
66 unsigned long n;
67 unsigned long len = length;
68 unsigned char tmp[AES_BLOCK_SIZE];
69 const unsigned char *iv = ivec;
70
71 assert(in && out && key && ivec);
72 assert((AES_ENCRYPT == enc)||(AES_DECRYPT == enc));
73
74 if (AES_ENCRYPT == enc) {
75 while (len >= AES_BLOCK_SIZE) {
76 for(n=0; n < AES_BLOCK_SIZE; ++n)
77 out[n] = in[n] ^ iv[n];
78 AES_encrypt(out, out, key);
79 iv = out;
80 len -= AES_BLOCK_SIZE;
81 in += AES_BLOCK_SIZE;
82 out += AES_BLOCK_SIZE;
83 }
84 if (len) {
85 for(n=0; n < len; ++n)
86 out[n] = in[n] ^ iv[n];
87 for(n=len; n < AES_BLOCK_SIZE; ++n)
88 out[n] = iv[n];
89 AES_encrypt(out, out, key);
90 iv = out;
91 }
92 memcpy(ivec,iv,AES_BLOCK_SIZE);
93 } else if (in != out) {
94 while (len >= AES_BLOCK_SIZE) {
95 AES_decrypt(in, out, key);
96 for(n=0; n < AES_BLOCK_SIZE; ++n)
97 out[n] ^= iv[n];
98 iv = in;
99 len -= AES_BLOCK_SIZE;
100 in += AES_BLOCK_SIZE;
101 out += AES_BLOCK_SIZE;
102 }
103 if (len) {
104 AES_decrypt(in,tmp,key);
105 for(n=0; n < len; ++n)
106 out[n] = tmp[n] ^ iv[n];
107 iv = in;
108 }
109 memcpy(ivec,iv,AES_BLOCK_SIZE);
110 } else {
111 while (len >= AES_BLOCK_SIZE) {
112 memcpy(tmp, in, AES_BLOCK_SIZE);
113 AES_decrypt(in, out, key);
114 for(n=0; n < AES_BLOCK_SIZE; ++n)
115 out[n] ^= ivec[n];
116 memcpy(ivec, tmp, AES_BLOCK_SIZE);
117 len -= AES_BLOCK_SIZE;
118 in += AES_BLOCK_SIZE;
119 out += AES_BLOCK_SIZE;
120 }
121 if (len) {
122 memcpy(tmp, in, AES_BLOCK_SIZE);
123 AES_decrypt(tmp, out, key);
124 for(n=0; n < len; ++n)
125 out[n] ^= ivec[n];
126 for(n=len; n < AES_BLOCK_SIZE; ++n)
127 out[n] = tmp[n];
128 memcpy(ivec, tmp, AES_BLOCK_SIZE);
129 }
130 }
131 }
132