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 * [email protected].
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 "internal.h"
53
54
55 static_assert(16 % sizeof(size_t) == 0, "block cannot be divided into size_t");
56
CRYPTO_ofb128_encrypt(const uint8_t * in,uint8_t * out,size_t len,const AES_KEY * key,uint8_t ivec[16],unsigned * num,block128_f block)57 void CRYPTO_ofb128_encrypt(const uint8_t *in, uint8_t *out, size_t len,
58 const AES_KEY *key, uint8_t ivec[16], unsigned *num,
59 block128_f block) {
60 assert(key != NULL && ivec != NULL && num != NULL);
61 assert(len == 0 || (in != NULL && out != NULL));
62
63 unsigned n = *num;
64
65 while (n && len) {
66 *(out++) = *(in++) ^ ivec[n];
67 --len;
68 n = (n + 1) % 16;
69 }
70
71 while (len >= 16) {
72 (*block)(ivec, ivec, key);
73 CRYPTO_xor16(out, in, ivec);
74 len -= 16;
75 out += 16;
76 in += 16;
77 n = 0;
78 }
79 if (len) {
80 (*block)(ivec, ivec, key);
81 while (len--) {
82 out[n] = in[n] ^ ivec[n];
83 ++n;
84 }
85 }
86 *num = n;
87 }
88