crypto/des/cfb64ede.c

   1 /* crypto/des/cfb64ede.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 /* The input and output encrypted as though 64bit cfb mode is being
  62  * used.  The extra state information to record how much of the
  63  * 64bit block we have used is contained in *num;
  64  */
  65
  66 void des_ede3_cfb64_encrypt(in, out, length, ks1,ks2,ks3, ivec, num, enc)
  67 unsigned char *in;
  68 unsigned char *out;
  69 long length;
  70 des_key_schedule ks1,ks2,ks3;
  71 des_cblock (*ivec);
  72 int *num;
  73 int enc;
  74         {
  75         register DES_LONG v0,v1;
  76         register long l=length;
  77         register int n= *num;
  78         DES_LONG ti[2];
  79         unsigned char *iv,c,cc;
  80
  81         iv=(unsigned char *)ivec;
  82         if (enc)
  83                 {
  84                 while (l--)
  85                         {
  86                         if (n == 0)
  87                                 {
  88                                 c2l(iv,v0);
  89                                 c2l(iv,v1);
  90
  91                                 ti[0]=v0;
  92                                 ti[1]=v1;
  93                                 des_encrypt3((DES_LONG *)ti,ks1,ks2,ks3);
  94                                 v0=ti[0];
  95                                 v1=ti[1];
  96
  97                                 iv=(unsigned char *)ivec;
  98                                 l2c(v0,iv);
  99                                 l2c(v1,iv);
 100                                 iv=(unsigned char *)ivec;
 101                                 }
 102                         c= *(in++)^iv[n];
 103                         *(out++)=c;
 104                         iv[n]=c;
 105                         n=(n+1)&0x07;
 106                         }
 107                 }
 108         else
 109                 {
 110                 while (l--)
 111                         {
 112                         if (n == 0)
 113                                 {
 114                                 c2l(iv,v0);
 115                                 c2l(iv,v1);
 116
 117                                 ti[0]=v0;
 118                                 ti[1]=v1;
 119                                 des_encrypt3((DES_LONG *)ti,ks1,ks2,ks3);
 120                                 v0=ti[0];
 121                                 v1=ti[1];
 122
 123                                 iv=(unsigned char *)ivec;
 124                                 l2c(v0,iv);
 125                                 l2c(v1,iv);
 126                                 iv=(unsigned char *)ivec;
 127                                 }
 128                         cc= *(in++);
 129                         c=iv[n];
 130                         iv[n]=cc;
 131                         *(out++)=c^cc;
 132                         n=(n+1)&0x07;
 133                         }
 134                 }
 135         v0=v1=ti[0]=ti[1]=c=cc=0;
 136         *num=n;
 137         }
 138
 139 #ifdef undef /* MACRO */
 140 void des_ede2_cfb64_encrypt(in, out, length, ks1,ks2, ivec, num, enc)
 141 unsigned char *in;
 142 unsigned char *out;
 143 long length;
 144 des_key_schedule ks1,ks2;
 145 des_cblock (*ivec);
 146 int *num;
 147 int enc;
 148         {
 149         des_ede3_cfb64_encrypt(in,out,length,ks1,ks2,ks1,ivec,num,enc);
 150         }
 151 #endif