crypto/modes/cbc128.c

   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 1
  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 #  define STRICT_ALIGNMENT 0
  68 #endif
  69
  70 void CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
  71                         size_t len, const void *key,
  72                         unsigned char ivec[16], block128_f block)
  73 {
  74         size_t n;
  75         const unsigned char *iv = ivec;
  76
  77         assert(in && out && key && ivec);
  78
  79 #if !defined(OPENSSL_SMALL_FOOTPRINT)
  80         if (STRICT_ALIGNMENT &&
  81             ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
  82                 while (len>=16) {
  83                         for(n=0; n<16; ++n)
  84                                 out[n] = in[n] ^ iv[n];
  85                         (*block)(out, out, key);
  86                         iv = out;
  87                         len -= 16;
  88                         in  += 16;
  89                         out += 16;
  90                 }
  91         } else {
  92                 while (len>=16) {
  93                         for(n=0; n<16; n+=sizeof(size_t))
  94                                 *(size_t*)(out+n) =
  95                                 *(size_t*)(in+n) ^ *(size_t*)(iv+n);
  96                         (*block)(out, out, key);
  97                         iv = out;
  98                         len -= 16;
  99                         in  += 16;
 100                         out += 16;
 101                 }
 102         }
 103 #endif
 104         while (len) {
 105                 for(n=0; n<16 && n<len; ++n)
 106                         out[n] = in[n] ^ iv[n];
 107                 for(; n<16; ++n)
 108                         out[n] = iv[n];
 109                 (*block)(out, out, key);
 110                 iv = out;
 111                 if (len<=16) break;
 112                 len -= 16;
 113                 in  += 16;
 114                 out += 16;
 115         }
 116         memcpy(ivec,iv,16);
 117 }
 118
 119 void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
 120                         size_t len, const void *key,
 121                         unsigned char ivec[16], block128_f block)
 122 {
 123         size_t n;
 124         union { size_t align; unsigned char c[16]; } tmp;
 125
 126         assert(in && out && key && ivec);
 127
 128 #if !defined(OPENSSL_SMALL_FOOTPRINT)
 129         if (in != out) {
 130                 const unsigned char *iv = ivec;
 131
 132                 if (STRICT_ALIGNMENT &&
 133                     ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
 134                         while (len>=16) {
 135                                 (*block)(in, out, key);
 136                                 for(n=0; n<16; ++n)
 137                                         out[n] ^= iv[n];
 138                                 iv = in;
 139                                 len -= 16;
 140                                 in  += 16;
 141                                 out += 16;
 142                         }
 143                 }
 144                 else {
 145                         while (len>=16) {
 146                                 (*block)(in, out, key);
 147                                 for(n=0; n<16; n+=sizeof(size_t))
 148                                         *(size_t *)(out+n) ^= *(size_t *)(iv+n);
 149                                 iv = in;
 150                                 len -= 16;
 151                                 in  += 16;
 152                                 out += 16;
 153                         }
 154                 }
 155                 memcpy(ivec,iv,16);
 156         } else {
 157                 if (STRICT_ALIGNMENT &&
 158                     ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
 159                         unsigned char c;
 160                         while (len>=16) {
 161                                 (*block)(in, tmp.c, key);
 162                                 for(n=0; n<16; ++n) {
 163                                         c = in[n];
 164                                         out[n] = tmp.c[n] ^ ivec[n];
 165                                         ivec[n] = c;
 166                                 }
 167                                 len -= 16;
 168                                 in  += 16;
 169                                 out += 16;
 170                         }
 171                 }
 172                 else {
 173                         size_t c;
 174                         while (len>=16) {
 175                                 (*block)(in, tmp.c, key);
 176                                 for(n=0; n<16; n+=sizeof(size_t)) {
 177                                         c = *(size_t *)(in+n);
 178                                         *(size_t *)(out+n) =
 179                                         *(size_t *)(tmp.c+n) ^ *(size_t *)(ivec+n);
 180                                         *(size_t *)(ivec+n) = c;
 181                                 }
 182                                 len -= 16;
 183                                 in  += 16;
 184                                 out += 16;
 185                         }
 186                 }
 187         }
 188 #endif
 189         while (len) {
 190                 unsigned char c;
 191                 (*block)(in, tmp.c, key);
 192                 for(n=0; n<16 && n<len; ++n) {
 193                         c = in[n];
 194                         out[n] = tmp.c[n] ^ ivec[n];
 195                         ivec[n] = c;
 196                 }
 197                 if (len<=16) {
 198                         for (; n<16; ++n)
 199                                 ivec[n] = in[n];
 200                         break;
 201                 }
 202                 len -= 16;
 203                 in  += 16;
 204                 out += 16;
 205         }
 206 }