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 */
50
51 #include "modes.h"
52 #include <string.h>
53
54 #ifndef MODES_DEBUG
55 # ifndef NDEBUG
56 # define NDEBUG
57 # endif
58 #endif
59 #include <assert.h>
60
61 #define STRICT_ALIGNMENT
62 #if defined(__i386) || defined(__i386__) || \
63 defined(__x86_64) || defined(__x86_64__) || \
64 defined(_M_IX86) || defined(_M_AMD64) || defined(_M_X64) || \
65 defined(__s390__) || defined(__s390x__)
66 # undef STRICT_ALIGNMENT
67 #endif
68
69 /* The input and output encrypted as though 128bit ofb mode is being
70 * used. The extra state information to record how much of the
71 * 128bit block we have used is contained in *num;
72 */
CRYPTO_ofb128_encrypt(const unsigned char * in,unsigned char * out,size_t len,const void * key,unsigned char ivec[16],int * num,block128_f block)73 void CRYPTO_ofb128_encrypt(const unsigned char *in, unsigned char *out,
74 size_t len, const void *key,
75 unsigned char ivec[16], int *num,
76 block128_f block)
77 {
78 unsigned int n;
79 size_t l=0;
80
81 assert(in && out && key && ivec && num);
82
83 n = *num;
84
85 #if !defined(OPENSSL_SMALL_FOOTPRINT)
86 if (16%sizeof(size_t) == 0) do { /* always true actually */
87 while (n && len) {
88 *(out++) = *(in++) ^ ivec[n];
89 --len;
90 n = (n+1) % 16;
91 }
92 #if defined(STRICT_ALIGNMENT)
93 if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)
94 break;
95 #endif
96 while (len>=16) {
97 (*block)(ivec, ivec, key);
98 for (; n<16; n+=sizeof(size_t))
99 *(size_t*)(out+n) =
100 *(size_t*)(in+n) ^ *(size_t*)(ivec+n);
101 len -= 16;
102 out += 16;
103 in += 16;
104 n = 0;
105 }
106 if (len) {
107 (*block)(ivec, ivec, key);
108 while (len--) {
109 out[n] = in[n] ^ ivec[n];
110 ++n;
111 }
112 }
113 *num = n;
114 return;
115 } while(0);
116 /* the rest would be commonly eliminated by x86* compiler */
117 #endif
118 while (l<len) {
119 if (n==0) {
120 (*block)(ivec, ivec, key);
121 }
122 out[l] = in[l] ^ ivec[n];
123 ++l;
124 n = (n+1) % 16;
125 }
126
127 *num=n;
128 }
129