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 <openssl/modes.h>
50
51#include <assert.h>
52
53#include "internal.h"
54
55
56void CRYPTO_ofb128_encrypt(const uint8_t *in, uint8_t *out, size_t len,
57                           const void *key, uint8_t ivec[16], int *num,
58                           block128_f block) {
59  unsigned int n;
60  size_t l=0;
61
62  assert(in && out && key && ivec && num);
63  assert((16 % sizeof(size_t)) == 0);
64
65  n = *num;
66
67  while (n && len) {
68    *(out++) = *(in++) ^ ivec[n];
69    --len;
70    n = (n + 1) % 16;
71  }
72
73  if (STRICT_ALIGNMENT &&
74      ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {
75    while (l < len) {
76      if (n == 0) {
77        (*block)(ivec, ivec, key);
78      }
79      out[l] = in[l] ^ ivec[n];
80      ++l;
81      n = (n + 1) % 16;
82    }
83
84    *num = n;
85    return;
86  }
87
88  while (len >= 16) {
89    (*block)(ivec, ivec, key);
90    for (; n < 16; n += sizeof(size_t)) {
91      *(size_t *)(out + n) = *(size_t *)(in + n) ^ *(size_t *)(ivec + n);
92    }
93    len -= 16;
94    out += 16;
95    in += 16;
96    n = 0;
97  }
98  if (len) {
99    (*block)(ivec, ivec, key);
100    while (len--) {
101      out[n] = in[n] ^ ivec[n];
102      ++n;
103    }
104  }
105  *num = n;
106}
107