crypto/rc5/rc5_enc.c

   1 /* crypto/rc5/rc5_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 <stdio.h>
  60 #include "rc5.h"
  61 #include "rc5_locl.h"
  62
  63 void RC5_32_cbc_encrypt(in, out, length, ks, iv, encrypt)
  64 unsigned char *in;
  65 unsigned char *out;
  66 long length;
  67 RC5_32_KEY *ks;
  68 unsigned char *iv;
  69 int encrypt;
  70         {
  71         register unsigned long tin0,tin1;
  72         register unsigned long tout0,tout1,xor0,xor1;
  73         register long l=length;
  74         unsigned long tin[2];
  75
  76         if (encrypt)
  77                 {
  78                 c2l(iv,tout0);
  79                 c2l(iv,tout1);
  80                 iv-=8;
  81                 for (l-=8; l>=0; l-=8)
  82                         {
  83                         c2l(in,tin0);
  84                         c2l(in,tin1);
  85                         tin0^=tout0;
  86                         tin1^=tout1;
  87                         tin[0]=tin0;
  88                         tin[1]=tin1;
  89                         RC5_32_encrypt(tin,ks);
  90                         tout0=tin[0]; l2c(tout0,out);
  91                         tout1=tin[1]; l2c(tout1,out);
  92                         }
  93                 if (l != -8)
  94                         {
  95                         c2ln(in,tin0,tin1,l+8);
  96                         tin0^=tout0;
  97                         tin1^=tout1;
  98                         tin[0]=tin0;
  99                         tin[1]=tin1;
 100                         RC5_32_encrypt(tin,ks);
 101                         tout0=tin[0]; l2c(tout0,out);
 102                         tout1=tin[1]; l2c(tout1,out);
 103                         }
 104                 l2c(tout0,iv);
 105                 l2c(tout1,iv);
 106                 }
 107         else
 108                 {
 109                 c2l(iv,xor0);
 110                 c2l(iv,xor1);
 111                 iv-=8;
 112                 for (l-=8; l>=0; l-=8)
 113                         {
 114                         c2l(in,tin0); tin[0]=tin0;
 115                         c2l(in,tin1); tin[1]=tin1;
 116                         RC5_32_decrypt(tin,ks);
 117                         tout0=tin[0]^xor0;
 118                         tout1=tin[1]^xor1;
 119                         l2c(tout0,out);
 120                         l2c(tout1,out);
 121                         xor0=tin0;
 122                         xor1=tin1;
 123                         }
 124                 if (l != -8)
 125                         {
 126                         c2l(in,tin0); tin[0]=tin0;
 127                         c2l(in,tin1); tin[1]=tin1;
 128                         RC5_32_decrypt(tin,ks);
 129                         tout0=tin[0]^xor0;
 130                         tout1=tin[1]^xor1;
 131                         l2cn(tout0,tout1,out,l+8);
 132                         xor0=tin0;
 133                         xor1=tin1;
 134                         }
 135                 l2c(xor0,iv);
 136                 l2c(xor1,iv);
 137                 }
 138         tin0=tin1=tout0=tout1=xor0=xor1=0;
 139         tin[0]=tin[1]=0;
 140         }
 141
 142 void RC5_32_encrypt(d,key)
 143 unsigned long *d;
 144 RC5_32_KEY *key;
 145         {
 146         RC5_32_INT a,b,*s;
 147
 148         s=key->data;
 149
 150         a=d[0]+s[0];
 151         b=d[1]+s[1];
 152         E_RC5_32(a,b,s, 2);
 153         E_RC5_32(a,b,s, 4);
 154         E_RC5_32(a,b,s, 6);
 155         E_RC5_32(a,b,s, 8);
 156         E_RC5_32(a,b,s,10);
 157         E_RC5_32(a,b,s,12);
 158         E_RC5_32(a,b,s,14);
 159         E_RC5_32(a,b,s,16);
 160         if (key->rounds == 12)
 161                 {
 162                 E_RC5_32(a,b,s,18);
 163                 E_RC5_32(a,b,s,20);
 164                 E_RC5_32(a,b,s,22);
 165                 E_RC5_32(a,b,s,24);
 166                 }
 167         else if (key->rounds == 16)
 168                 {
 169                 /* Do a full expansion to avoid a jump */
 170                 E_RC5_32(a,b,s,18);
 171                 E_RC5_32(a,b,s,20);
 172                 E_RC5_32(a,b,s,22);
 173                 E_RC5_32(a,b,s,24);
 174                 E_RC5_32(a,b,s,26);
 175                 E_RC5_32(a,b,s,28);
 176                 E_RC5_32(a,b,s,30);
 177                 E_RC5_32(a,b,s,32);
 178                 }
 179         d[0]=a;
 180         d[1]=b;
 181         }
 182
 183 void RC5_32_decrypt(d,key)
 184 unsigned long *d;
 185 RC5_32_KEY *key;
 186         {
 187         RC5_32_INT a,b,*s;
 188
 189         s=key->data;
 190
 191         a=d[0];
 192         b=d[1];
 193         if (key->rounds == 16)
 194                 {
 195                 D_RC5_32(a,b,s,32);
 196                 D_RC5_32(a,b,s,30);
 197                 D_RC5_32(a,b,s,28);
 198                 D_RC5_32(a,b,s,26);
 199                 /* Do a full expansion to avoid a jump */
 200                 D_RC5_32(a,b,s,24);
 201                 D_RC5_32(a,b,s,22);
 202                 D_RC5_32(a,b,s,20);
 203                 D_RC5_32(a,b,s,18);
 204                 }
 205         else if (key->rounds == 12)
 206                 {
 207                 D_RC5_32(a,b,s,24);
 208                 D_RC5_32(a,b,s,22);
 209                 D_RC5_32(a,b,s,20);
 210                 D_RC5_32(a,b,s,18);
 211                 }
 212         D_RC5_32(a,b,s,16);
 213         D_RC5_32(a,b,s,14);
 214         D_RC5_32(a,b,s,12);
 215         D_RC5_32(a,b,s,10);
 216         D_RC5_32(a,b,s, 8);
 217         D_RC5_32(a,b,s, 6);
 218         D_RC5_32(a,b,s, 4);
 219         D_RC5_32(a,b,s, 2);
 220         d[0]=a-s[0];
 221         d[1]=b-s[1];
 222         }
 223