crypto/des/pcbc_enc.c

   1 /* crypto/des/pcbc_enc.c */
   2 /* Copyright (C) 1995-1997 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(input, output, length, schedule, ivec, enc)
  62 des_cblock (*input);
  63 des_cblock (*output);
  64 long length;
  65 des_key_schedule schedule;
  66 des_cblock (*ivec);
  67 int enc;
  68         {
  69         register DES_LONG sin0,sin1,xor0,xor1,tout0,tout1;
  70         DES_LONG tin[2];
  71         unsigned char *in,*out,*iv;
  72
  73         in=(unsigned char *)input;
  74         out=(unsigned char *)output;
  75         iv=(unsigned char *)ivec;
  76
  77         if (enc)
  78                 {
  79                 c2l(iv,xor0);
  80                 c2l(iv,xor1);
  81                 for (; length>0; length-=8)
  82                         {
  83                         if (length >= 8)
  84                                 {
  85                                 c2l(in,sin0);
  86                                 c2l(in,sin1);
  87                                 }
  88                         else
  89                                 c2ln(in,sin0,sin1,length);
  90                         tin[0]=sin0^xor0;
  91                         tin[1]=sin1^xor1;
  92                         des_encrypt((DES_LONG *)tin,schedule,DES_ENCRYPT);
  93                         tout0=tin[0];
  94                         tout1=tin[1];
  95                         xor0=sin0^tout0;
  96                         xor1=sin1^tout1;
  97                         l2c(tout0,out);
  98                         l2c(tout1,out);
  99                         }
 100                 }
 101         else
 102                 {
 103                 c2l(iv,xor0); c2l(iv,xor1);
 104                 for (; length>0; length-=8)
 105                         {
 106                         c2l(in,sin0);
 107                         c2l(in,sin1);
 108                         tin[0]=sin0;
 109                         tin[1]=sin1;
 110                         des_encrypt((DES_LONG *)tin,schedule,DES_DECRYPT);
 111                         tout0=tin[0]^xor0;
 112                         tout1=tin[1]^xor1;
 113                         if (length >= 8)
 114                                 {
 115                                 l2c(tout0,out);
 116                                 l2c(tout1,out);
 117                                 }
 118                         else
 119                                 l2cn(tout0,tout1,out,length);
 120                         xor0=tout0^sin0;
 121                         xor1=tout1^sin1;
 122                         }
 123                 }
 124         tin[0]=tin[1]=0;
 125         sin0=sin1=xor0=xor1=tout0=tout1=0;
 126         }