crypto/seed/seed_cbc.c

   1 /* crypto/seed/seed_cbc.c -*- mode:C; c-file-style: "eay" -*- */
   2 /* ====================================================================
   3  * Copyright (c) 1998-2007 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 "seed_locl.h"
  53 #include <string.h>
  54
  55 void SEED_cbc_encrypt(const unsigned char *in, unsigned char *out,
  56                       size_t len, const SEED_KEY_SCHEDULE *ks,
  57                       unsigned char ivec[SEED_BLOCK_SIZE], int enc)
  58         {
  59         size_t n;
  60         unsigned char tmp[SEED_BLOCK_SIZE];
  61         const unsigned char *iv = ivec;
  62
  63         if (enc)
  64                 {
  65                 while (len >= SEED_BLOCK_SIZE)
  66                         {
  67                         for (n = 0; n < SEED_BLOCK_SIZE; ++n)
  68                                 out[n] = in[n] ^ iv[n];
  69                         SEED_encrypt(out, out, ks);
  70                         iv = out;
  71                         len -= SEED_BLOCK_SIZE;
  72                         in  += SEED_BLOCK_SIZE;
  73                         out += SEED_BLOCK_SIZE;
  74                         }
  75                 if (len)
  76                         {
  77                         for (n = 0; n < len; ++n)
  78                                 out[n] = in[n] ^ iv[n];
  79                         for (n = len; n < SEED_BLOCK_SIZE; ++n)
  80                                 out[n] = iv[n];
  81                         SEED_encrypt(out, out, ks);
  82                         iv = out;
  83                         }
  84                 memcpy(ivec, iv, SEED_BLOCK_SIZE);
  85                 }
  86         else if (in != out) /* decrypt */
  87                 {
  88                 while (len >= SEED_BLOCK_SIZE)
  89                         {
  90                         SEED_decrypt(in, out, ks);
  91                         for (n = 0; n < SEED_BLOCK_SIZE; ++n)
  92                                 out[n] ^= iv[n];
  93                         iv = in;
  94                         len -= SEED_BLOCK_SIZE;
  95                         in  += SEED_BLOCK_SIZE;
  96                         out += SEED_BLOCK_SIZE;
  97                         }
  98                 if (len)
  99                         {
 100                         SEED_decrypt(in, tmp, ks);
 101                         for (n = 0; n < len; ++n)
 102                                 out[n] = tmp[n] ^ iv[n];
 103                         iv = in;
 104                         }
 105                 memcpy(ivec, iv, SEED_BLOCK_SIZE);
 106                 }
 107         else /* decrypt, overlap */
 108                 {
 109                 while (len >= SEED_BLOCK_SIZE)
 110                         {
 111                         memcpy(tmp, in, SEED_BLOCK_SIZE);
 112                         SEED_decrypt(in, out, ks);
 113                         for (n = 0; n < SEED_BLOCK_SIZE; ++n)
 114                                 out[n] ^= ivec[n];
 115                         memcpy(ivec, tmp, SEED_BLOCK_SIZE);
 116                         len -= SEED_BLOCK_SIZE;
 117                         in  += SEED_BLOCK_SIZE;
 118                         out += SEED_BLOCK_SIZE;
 119                         }
 120                 if (len)
 121                         {
 122                         memcpy(tmp, in, SEED_BLOCK_SIZE);
 123                         SEED_decrypt(tmp, tmp, ks);
 124                         for (n = 0; n < len; ++n)
 125                                 out[n] = tmp[n] ^ ivec[n];
 126                         memcpy(ivec, tmp, SEED_BLOCK_SIZE);
 127                         }
 128                 }
 129         }