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_lcl.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 #ifndef STRICT_ALIGNMENT
  62 #  define STRICT_ALIGNMENT 0
  63 #endif
  64
  65 void CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
  66                         size_t len, const void *key,
  67                         unsigned char ivec[16], block128_f block)
  68 {
  69         size_t n;
  70         const unsigned char *iv = ivec;
  71
  72         assert(in && out && key && ivec);
  73
  74 #if !defined(OPENSSL_SMALL_FOOTPRINT)
  75         if (STRICT_ALIGNMENT &&
  76             ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
  77                 while (len>=16) {
  78                         for(n=0; n<16; ++n)
  79                                 out[n] = in[n] ^ iv[n];
  80                         (*block)(out, out, key);
  81                         iv = out;
  82                         len -= 16;
  83                         in  += 16;
  84                         out += 16;
  85                 }
  86         } else {
  87                 while (len>=16) {
  88                         for(n=0; n<16; n+=sizeof(size_t))
  89                                 *(size_t*)(out+n) =
  90                                 *(size_t*)(in+n) ^ *(size_t*)(iv+n);
  91                         (*block)(out, out, key);
  92                         iv = out;
  93                         len -= 16;
  94                         in  += 16;
  95                         out += 16;
  96                 }
  97         }
  98 #endif
  99         while (len) {
 100                 for(n=0; n<16 && n<len; ++n)
 101                         out[n] = in[n] ^ iv[n];
 102                 for(; n<16; ++n)
 103                         out[n] = iv[n];
 104                 (*block)(out, out, key);
 105                 iv = out;
 106                 if (len<=16) break;
 107                 len -= 16;
 108                 in  += 16;
 109                 out += 16;
 110         }
 111         memcpy(ivec,iv,16);
 112 }
 113
 114 void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
 115                         size_t len, const void *key,
 116                         unsigned char ivec[16], block128_f block)
 117 {
 118         size_t n;
 119         union { size_t align; unsigned char c[16]; } tmp;
 120
 121         assert(in && out && key && ivec);
 122
 123 #if !defined(OPENSSL_SMALL_FOOTPRINT)
 124         if (in != out) {
 125                 const unsigned char *iv = ivec;
 126
 127                 if (STRICT_ALIGNMENT &&
 128                     ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
 129                         while (len>=16) {
 130                                 (*block)(in, out, key);
 131                                 for(n=0; n<16; ++n)
 132                                         out[n] ^= iv[n];
 133                                 iv = in;
 134                                 len -= 16;
 135                                 in  += 16;
 136                                 out += 16;
 137                         }
 138                 }
 139                 else {
 140                         while (len>=16) {
 141                                 (*block)(in, out, key);
 142                                 for(n=0; n<16; n+=sizeof(size_t))
 143                                         *(size_t *)(out+n) ^= *(size_t *)(iv+n);
 144                                 iv = in;
 145                                 len -= 16;
 146                                 in  += 16;
 147                                 out += 16;
 148                         }
 149                 }
 150                 memcpy(ivec,iv,16);
 151         } else {
 152                 if (STRICT_ALIGNMENT &&
 153                     ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
 154                         unsigned char c;
 155                         while (len>=16) {
 156                                 (*block)(in, tmp.c, key);
 157                                 for(n=0; n<16; ++n) {
 158                                         c = in[n];
 159                                         out[n] = tmp.c[n] ^ ivec[n];
 160                                         ivec[n] = c;
 161                                 }
 162                                 len -= 16;
 163                                 in  += 16;
 164                                 out += 16;
 165                         }
 166                 }
 167                 else {
 168                         size_t c;
 169                         while (len>=16) {
 170                                 (*block)(in, tmp.c, key);
 171                                 for(n=0; n<16; n+=sizeof(size_t)) {
 172                                         c = *(size_t *)(in+n);
 173                                         *(size_t *)(out+n) =
 174                                         *(size_t *)(tmp.c+n) ^ *(size_t *)(ivec+n);
 175                                         *(size_t *)(ivec+n) = c;
 176                                 }
 177                                 len -= 16;
 178                                 in  += 16;
 179                                 out += 16;
 180                         }
 181                 }
 182         }
 183 #endif
 184         while (len) {
 185                 unsigned char c;
 186                 (*block)(in, tmp.c, key);
 187                 for(n=0; n<16 && n<len; ++n) {
 188                         c = in[n];
 189                         out[n] = tmp.c[n] ^ ivec[n];
 190                         ivec[n] = c;
 191                 }
 192                 if (len<=16) {
 193                         for (; n<16; ++n)
 194                                 ivec[n] = in[n];
 195                         break;
 196                 }
 197                 len -= 16;
 198                 in  += 16;
 199                 out += 16;
 200         }
 201 }