crypto/des/pcbc_enc.c

   1 /* crypto/des/pcbc_enc.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include "des_locl.h"
  60
  61 void DES_pcbc_encrypt(const unsigned char *input, unsigned char *output,
  62                       long length, DES_key_schedule *schedule,
  63                       DES_cblock *ivec, int enc)
  64 {
  65     register DES_LONG sin0, sin1, xor0, xor1, tout0, tout1;
  66     DES_LONG tin[2];
  67     const unsigned char *in;
  68     unsigned char *out, *iv;
  69
  70     in = input;
  71     out = output;
  72     iv = &(*ivec)[0];
  73
  74     if (enc) {
  75         c2l(iv, xor0);
  76         c2l(iv, xor1);
  77         for (; length > 0; length -= 8) {
  78             if (length >= 8) {
  79                 c2l(in, sin0);
  80                 c2l(in, sin1);
  81             } else
  82                 c2ln(in, sin0, sin1, length);
  83             tin[0] = sin0 ^ xor0;
  84             tin[1] = sin1 ^ xor1;
  85             DES_encrypt1((DES_LONG *)tin, schedule, DES_ENCRYPT);
  86             tout0 = tin[0];
  87             tout1 = tin[1];
  88             xor0 = sin0 ^ tout0;
  89             xor1 = sin1 ^ tout1;
  90             l2c(tout0, out);
  91             l2c(tout1, out);
  92         }
  93     } else {
  94         c2l(iv, xor0);
  95         c2l(iv, xor1);
  96         for (; length > 0; length -= 8) {
  97             c2l(in, sin0);
  98             c2l(in, sin1);
  99             tin[0] = sin0;
 100             tin[1] = sin1;
 101             DES_encrypt1((DES_LONG *)tin, schedule, DES_DECRYPT);
 102             tout0 = tin[0] ^ xor0;
 103             tout1 = tin[1] ^ xor1;
 104             if (length >= 8) {
 105                 l2c(tout0, out);
 106                 l2c(tout1, out);
 107             } else
 108                 l2cn(tout0, tout1, out, length);
 109             xor0 = tout0 ^ sin0;
 110             xor1 = tout1 ^ sin1;
 111         }
 112     }
 113     tin[0] = tin[1] = 0;
 114     sin0 = sin1 = xor0 = xor1 = tout0 = tout1 = 0;
 115 }