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 <stddef.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 #include "modes.h"
  62
  63 #define STRICT_ALIGNMENT 1
  64 #if defined(__i386) || defined(__i386__) || \
  65     defined(__x86_64) || defined(__x86_64__) || \
  66     defined(_M_IX86) || defined(_M_AMD64) || defined(_M_X64) || \
  67     defined(__s390__) || defined(__s390x__)
  68 #  undef STRICT_ALIGNMENT
  69 #  define STRICT_ALIGNMENT 0
  70 #endif
  71
  72 void CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
  73                         size_t len, const void *key,
  74                         unsigned char ivec[16], block_f block)
  75 {
  76         size_t n;
  77         const unsigned char *iv = ivec;
  78
  79         assert(in && out && key && ivec);
  80
  81 #if !defined(OPENSSL_SMALL_FOOTPRINT)
  82         if (STRICT_ALIGNMENT &&
  83             ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
  84                 while (len>=16) {
  85                         for(n=0; n<16; ++n)
  86                                 out[n] = in[n] ^ iv[n];
  87                         (*block)(out, out, key);
  88                         iv = out;
  89                         len -= 16;
  90                         in  += 16;
  91                         out += 16;
  92                 }
  93         } else {
  94                 while (len>=16) {
  95                         for(n=0; n<16; n+=sizeof(size_t))
  96                                 *(size_t*)(out+n) =
  97                                 *(size_t*)(in+n) ^ *(size_t*)(iv+n);
  98                         (*block)(out, out, key);
  99                         iv = out;
 100                         len -= 16;
 101                         in  += 16;
 102                         out += 16;
 103                 }
 104         }
 105 #endif
 106         while (len) {
 107                 for(n=0; n<16 && n<len; ++n)
 108                         out[n] = in[n] ^ iv[n];
 109                 for(; n<16; ++n)
 110                         out[n] = iv[n];
 111                 (*block)(out, out, key);
 112                 iv = out;
 113                 if (len<=16) break;
 114                 len -= 16;
 115                 in  += 16;
 116                 out += 16;
 117         }
 118         memcpy(ivec,iv,16);
 119 }
 120
 121 void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
 122                         size_t len, const void *key,
 123                         unsigned char ivec[16], block_f block)
 124 {
 125         size_t n;
 126         union { size_t align; unsigned char c[16]; } tmp;
 127
 128         assert(in && out && key && ivec);
 129
 130 #if !defined(OPENSSL_SMALL_FOOTPRINT)
 131         if (in != out) {
 132                 const unsigned char *iv = ivec;
 133
 134                 if (STRICT_ALIGNMENT &&
 135                     ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
 136                         while (len>=16) {
 137                                 (*block)(in, out, key);
 138                                 for(n=0; n<16; ++n)
 139                                         out[n] ^= iv[n];
 140                                 iv = in;
 141                                 len -= 16;
 142                                 in  += 16;
 143                                 out += 16;
 144                         }
 145                 }
 146                 else {
 147                         while (len>=16) {
 148                                 (*block)(in, out, key);
 149                                 for(n=0; n<16; n+=sizeof(size_t))
 150                                         *(size_t *)(out+n) ^= *(size_t *)(iv+n);
 151                                 iv = in;
 152                                 len -= 16;
 153                                 in  += 16;
 154                                 out += 16;
 155                         }
 156                 }
 157                 memcpy(ivec,iv,16);
 158         } else {
 159                 if (STRICT_ALIGNMENT &&
 160                     ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
 161                         unsigned char c;
 162                         while (len>=16) {
 163                                 (*block)(in, tmp.c, key);
 164                                 for(n=0; n<16; ++n) {
 165                                         c = in[n];
 166                                         out[n] = tmp.c[n] ^ ivec[n];
 167                                         ivec[n] = c;
 168                                 }
 169                                 len -= 16;
 170                                 in  += 16;
 171                                 out += 16;
 172                         }
 173                 }
 174                 else {
 175                         size_t c;
 176                         while (len>=16) {
 177                                 (*block)(in, tmp.c, key);
 178                                 for(n=0; n<16; n+=sizeof(size_t)) {
 179                                         c = *(size_t *)(in+n);
 180                                         *(size_t *)(out+n) =
 181                                         *(size_t *)(tmp.c+n) ^ *(size_t *)(ivec+n);
 182                                         *(size_t *)(ivec+n) = c;
 183                                 }
 184                                 len -= 16;
 185                                 in  += 16;
 186                                 out += 16;
 187                         }
 188                 }
 189         }
 190 #endif
 191         while (len) {
 192                 unsigned char c;
 193                 (*block)(in, tmp.c, key);
 194                 for(n=0; n<16 && n<len; ++n) {
 195                         c = in[n];
 196                         out[n] = tmp.c[n] ^ ivec[n];
 197                         ivec[n] = c;
 198                 }
 199                 if (len<=16) {
 200                         for (; n<16; ++n)
 201                                 ivec[n] = in[n];
 202                         break;
 203                 }
 204                 len -= 16;
 205                 in  += 16;
 206                 out += 16;
 207         }
 208 }