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 <openssl/crypto.h>
  52 #include "modes_lcl.h"
  53 #include <string.h>
  54
  55 #ifndef MODES_DEBUG
  56 # ifndef NDEBUG
  57 #  define NDEBUG
  58 # endif
  59 #endif
  60 #include <assert.h>
  61
  62 #ifndef STRICT_ALIGNMENT
  63 #  define STRICT_ALIGNMENT 0
  64 #endif
  65
  66 void CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
  67                         size_t len, const void *key,
  68                         unsigned char ivec[16], block128_f block)
  69 {
  70         size_t n;
  71         const unsigned char *iv = ivec;
  72
  73         assert(in && out && key && ivec);
  74
  75 #if !defined(OPENSSL_SMALL_FOOTPRINT)
  76         if (STRICT_ALIGNMENT &&
  77             ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
  78                 while (len>=16) {
  79                         for(n=0; n<16; ++n)
  80                                 out[n] = in[n] ^ iv[n];
  81                         (*block)(out, out, key);
  82                         iv = out;
  83                         len -= 16;
  84                         in  += 16;
  85                         out += 16;
  86                 }
  87         } else {
  88                 while (len>=16) {
  89                         for(n=0; n<16; n+=sizeof(size_t))
  90                                 *(size_t*)(out+n) =
  91                                 *(size_t*)(in+n) ^ *(size_t*)(iv+n);
  92                         (*block)(out, out, key);
  93                         iv = out;
  94                         len -= 16;
  95                         in  += 16;
  96                         out += 16;
  97                 }
  98         }
  99 #endif
 100         while (len) {
 101                 for(n=0; n<16 && n<len; ++n)
 102                         out[n] = in[n] ^ iv[n];
 103                 for(; n<16; ++n)
 104                         out[n] = iv[n];
 105                 (*block)(out, out, key);
 106                 iv = out;
 107                 if (len<=16) break;
 108                 len -= 16;
 109                 in  += 16;
 110                 out += 16;
 111         }
 112         memcpy(ivec,iv,16);
 113 }
 114
 115 void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
 116                         size_t len, const void *key,
 117                         unsigned char ivec[16], block128_f block)
 118 {
 119         size_t n;
 120         union { size_t t[16/sizeof(size_t)]; unsigned char c[16]; } tmp;
 121
 122         assert(in && out && key && ivec);
 123
 124 #if !defined(OPENSSL_SMALL_FOOTPRINT)
 125         if (in != out) {
 126                 const unsigned char *iv = ivec;
 127
 128                 if (STRICT_ALIGNMENT &&
 129                     ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
 130                         while (len>=16) {
 131                                 (*block)(in, out, key);
 132                                 for(n=0; n<16; ++n)
 133                                         out[n] ^= iv[n];
 134                                 iv = in;
 135                                 len -= 16;
 136                                 in  += 16;
 137                                 out += 16;
 138                         }
 139                 }
 140                 else  if (16%sizeof(size_t) == 0) { /* always true */
 141                         while (len>=16) {
 142                                 size_t *out_t=(size_t *)out, *iv_t=(size_t *)iv;
 143
 144                                 (*block)(in, out, key);
 145                                 for(n=0; n<16/sizeof(size_t); n++)
 146                                         out_t[n] ^= iv_t[n];
 147                                 iv = in;
 148                                 len -= 16;
 149                                 in  += 16;
 150                                 out += 16;
 151                         }
 152                 }
 153                 memcpy(ivec,iv,16);
 154         } else {
 155                 if (STRICT_ALIGNMENT &&
 156                     ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
 157                         unsigned char c;
 158                         while (len>=16) {
 159                                 (*block)(in, tmp.c, key);
 160                                 for(n=0; n<16; ++n) {
 161                                         c = in[n];
 162                                         out[n] = tmp.c[n] ^ ivec[n];
 163                                         ivec[n] = c;
 164                                 }
 165                                 len -= 16;
 166                                 in  += 16;
 167                                 out += 16;
 168                         }
 169                 }
 170                 else if (16%sizeof(size_t) == 0) { /* always true */
 171                         while (len>=16) {
 172                                 size_t c, *out_t=(size_t *)out, *ivec_t=(size_t *)ivec;
 173                                 const size_t *in_t=(const size_t *)in;
 174
 175                                 (*block)(in, tmp.c, key);
 176                                 for(n=0; n<16/sizeof(size_t); n++) {
 177                                         c = in_t[n];
 178                                         out_t[n] = tmp.t[n] ^ ivec_t[n];
 179                                         ivec_t[n] = c;
 180                                 }
 181                                 len -= 16;
 182                                 in  += 16;
 183                                 out += 16;
 184                         }
 185                 }
 186         }
 187 #endif
 188         while (len) {
 189                 unsigned char c;
 190                 (*block)(in, tmp.c, key);
 191                 for(n=0; n<16 && n<len; ++n) {
 192                         c = in[n];
 193                         out[n] = tmp.c[n] ^ ivec[n];
 194                         ivec[n] = c;
 195                 }
 196                 if (len<=16) {
 197                         for (; n<16; ++n)
 198                                 ivec[n] = in[n];
 199                         break;
 200                 }
 201                 len -= 16;
 202                 in  += 16;
 203                 out += 16;
 204         }
 205 }