crypto/openssl/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 #if !defined(STRICT_ALIGNMENT) && !defined(PEDANTIC)
  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)
 108             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 {
 122         size_t t[16 / sizeof(size_t)];
 123         unsigned char c[16];
 124     } 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         } else if (16 % sizeof(size_t) == 0) { /* always true */
 144             while (len >= 16) {
 145                 size_t *out_t = (size_t *)out, *iv_t = (size_t *)iv;
 146
 147                 (*block) (in, out, key);
 148                 for (n = 0; n < 16 / sizeof(size_t); n++)
 149                     out_t[n] ^= iv_t[n];
 150                 iv = in;
 151                 len -= 16;
 152                 in += 16;
 153                 out += 16;
 154             }
 155         }
 156         memcpy(ivec, iv, 16);
 157     } else {
 158         if (STRICT_ALIGNMENT &&
 159             ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {
 160             unsigned char c;
 161             while (len >= 16) {
 162                 (*block) (in, tmp.c, key);
 163                 for (n = 0; n < 16; ++n) {
 164                     c = in[n];
 165                     out[n] = tmp.c[n] ^ ivec[n];
 166                     ivec[n] = c;
 167                 }
 168                 len -= 16;
 169                 in += 16;
 170                 out += 16;
 171             }
 172         } else if (16 % sizeof(size_t) == 0) { /* always true */
 173             while (len >= 16) {
 174                 size_t c, *out_t = (size_t *)out, *ivec_t = (size_t *)ivec;
 175                 const size_t *in_t = (const size_t *)in;
 176
 177                 (*block) (in, tmp.c, key);
 178                 for (n = 0; n < 16 / sizeof(size_t); n++) {
 179                     c = in_t[n];
 180                     out_t[n] = tmp.t[n] ^ ivec_t[n];
 181                     ivec_t[n] = c;
 182                 }
 183                 len -= 16;
 184                 in += 16;
 185                 out += 16;
 186             }
 187         }
 188     }
 189 #endif
 190     while (len) {
 191         unsigned char c;
 192         (*block) (in, tmp.c, key);
 193         for (n = 0; n < 16 && n < len; ++n) {
 194             c = in[n];
 195             out[n] = tmp.c[n] ^ ivec[n];
 196             ivec[n] = c;
 197         }
 198         if (len <= 16) {
 199             for (; n < 16; ++n)
 200                 ivec[n] = in[n];
 201             break;
 202         }
 203         len -= 16;
 204         in += 16;
 205         out += 16;
 206     }
 207 }