crypto/libressl/crypto/modes/cbc128.c

   1 /* $OpenBSD: cbc128.c,v 1.3 2014/06/12 15:49:30 deraadt Exp $ */
   2 /* ====================================================================
   3  * Copyright (c) 2008 The OpenSSL Project.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in
  14  *    the documentation and/or other materials provided with the
  15  *    distribution.
  16  *
  17  * 3. All advertising materials mentioning features or use of this
  18  *    software must display the following acknowledgment:
  19  *    "This product includes software developed by the OpenSSL Project
  20  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  21  *
  22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  23  *    endorse or promote products derived from this software without
  24  *    prior written permission. For written permission, please contact
  25  *    openssl-core@openssl.org.
  26  *
  27  * 5. Products derived from this software may not be called "OpenSSL"
  28  *    nor may "OpenSSL" appear in their names without prior written
  29  *    permission of the OpenSSL Project.
  30  *
  31  * 6. Redistributions of any form whatsoever must retain the following
  32  *    acknowledgment:
  33  *    "This product includes software developed by the OpenSSL Project
  34  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  47  * OF THE POSSIBILITY OF SUCH DAMAGE.
  48  * ====================================================================
  49  *
  50  */
  51
  52 #include <openssl/crypto.h>
  53 #include "modes_lcl.h"
  54 #include <string.h>
  55
  56 #ifndef MODES_DEBUG
  57 # ifndef NDEBUG
  58 #  define NDEBUG
  59 # endif
  60 #endif
  61
  62 #undef STRICT_ALIGNMENT
  63 #ifdef __STRICT_ALIGNMENT
  64 #define STRICT_ALIGNMENT 1
  65 #else
  66 #define STRICT_ALIGNMENT 0
  67 #endif
  68
  69 void CRYPTO_cbc128_encrypt(const unsigned char *in, unsigned char *out,
  70                         size_t len, const void *key,
  71                         unsigned char ivec[16], block128_f block)
  72 {
  73         size_t n;
  74         const unsigned char *iv = ivec;
  75
  76 #if !defined(OPENSSL_SMALL_FOOTPRINT)
  77         if (STRICT_ALIGNMENT &&
  78             ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
  79                 while (len>=16) {
  80                         for(n=0; n<16; ++n)
  81                                 out[n] = in[n] ^ iv[n];
  82                         (*block)(out, out, key);
  83                         iv = out;
  84                         len -= 16;
  85                         in  += 16;
  86                         out += 16;
  87                 }
  88         } else {
  89                 while (len>=16) {
  90                         for(n=0; n<16; n+=sizeof(size_t))
  91                                 *(size_t*)(out+n) =
  92                                 *(size_t*)(in+n) ^ *(size_t*)(iv+n);
  93                         (*block)(out, out, key);
  94                         iv = out;
  95                         len -= 16;
  96                         in  += 16;
  97                         out += 16;
  98                 }
  99         }
 100 #endif
 101         while (len) {
 102                 for(n=0; n<16 && n<len; ++n)
 103                         out[n] = in[n] ^ iv[n];
 104                 for(; n<16; ++n)
 105                         out[n] = iv[n];
 106                 (*block)(out, out, key);
 107                 iv = out;
 108                 if (len<=16) break;
 109                 len -= 16;
 110                 in  += 16;
 111                 out += 16;
 112         }
 113         memcpy(ivec,iv,16);
 114 }
 115
 116 void CRYPTO_cbc128_decrypt(const unsigned char *in, unsigned char *out,
 117                         size_t len, const void *key,
 118                         unsigned char ivec[16], block128_f block)
 119 {
 120         size_t n;
 121         union { size_t t[16/sizeof(size_t)]; unsigned char c[16]; } tmp;
 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                 } else if (16%sizeof(size_t) == 0) { /* always true */
 139                         while (len>=16) {
 140                                 size_t *out_t=(size_t *)out, *iv_t=(size_t *)iv;
 141
 142                                 (*block)(in, out, key);
 143                                 for(n=0; n<16/sizeof(size_t); n++)
 144                                         out_t[n] ^= iv_t[n];
 145                                 iv = in;
 146                                 len -= 16;
 147                                 in  += 16;
 148                                 out += 16;
 149                         }
 150                 }
 151                 memcpy(ivec,iv,16);
 152         } else {
 153                 if (STRICT_ALIGNMENT &&
 154                     ((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0) {
 155                         unsigned char c;
 156                         while (len>=16) {
 157                                 (*block)(in, tmp.c, key);
 158                                 for(n=0; n<16; ++n) {
 159                                         c = in[n];
 160                                         out[n] = tmp.c[n] ^ ivec[n];
 161                                         ivec[n] = c;
 162                                 }
 163                                 len -= 16;
 164                                 in  += 16;
 165                                 out += 16;
 166                         }
 167                 } else if (16%sizeof(size_t) == 0) { /* always true */
 168                         while (len>=16) {
 169                                 size_t c, *out_t=(size_t *)out, *ivec_t=(size_t *)ivec;
 170                                 const size_t *in_t=(const size_t *)in;
 171
 172                                 (*block)(in, tmp.c, key);
 173                                 for(n=0; n<16/sizeof(size_t); n++) {
 174                                         c = in_t[n];
 175                                         out_t[n] = tmp.t[n] ^ ivec_t[n];
 176                                         ivec_t[n] = c;
 177                                 }
 178                                 len -= 16;
 179                                 in  += 16;
 180                                 out += 16;
 181                         }
 182                 }
 183         }
 184 #endif
 185         while (len) {
 186                 unsigned char c;
 187                 (*block)(in, tmp.c, key);
 188                 for(n=0; n<16 && n<len; ++n) {
 189                         c = in[n];
 190                         out[n] = tmp.c[n] ^ ivec[n];
 191                         ivec[n] = c;
 192                 }
 193                 if (len<=16) {
 194                         for (; n<16; ++n)
 195                                 ivec[n] = in[n];
 196                         break;
 197                 }
 198                 len -= 16;
 199                 in  += 16;
 200                 out += 16;
 201         }
 202 }