crypto/rc2/rc2_cbc.c

   1 /* crypto/rc2/rc2_cbc.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 "rc2.h"
  60 #include "rc2_locl.h"
  61
  62 void RC2_cbc_encrypt(in, out, length, ks, iv, encrypt)
  63 unsigned char *in;
  64 unsigned char *out;
  65 long length;
  66 RC2_KEY *ks;
  67 unsigned char *iv;
  68 int encrypt;
  69         {
  70         register unsigned long tin0,tin1;
  71         register unsigned long tout0,tout1,xor0,xor1;
  72         register long l=length;
  73         unsigned long tin[2];
  74
  75         if (encrypt)
  76                 {
  77                 c2l(iv,tout0);
  78                 c2l(iv,tout1);
  79                 iv-=8;
  80                 for (l-=8; l>=0; l-=8)
  81                         {
  82                         c2l(in,tin0);
  83                         c2l(in,tin1);
  84                         tin0^=tout0;
  85                         tin1^=tout1;
  86                         tin[0]=tin0;
  87                         tin[1]=tin1;
  88                         RC2_encrypt(tin,ks);
  89                         tout0=tin[0]; l2c(tout0,out);
  90                         tout1=tin[1]; l2c(tout1,out);
  91                         }
  92                 if (l != -8)
  93                         {
  94                         c2ln(in,tin0,tin1,l+8);
  95                         tin0^=tout0;
  96                         tin1^=tout1;
  97                         tin[0]=tin0;
  98                         tin[1]=tin1;
  99                         RC2_encrypt(tin,ks);
 100                         tout0=tin[0]; l2c(tout0,out);
 101                         tout1=tin[1]; l2c(tout1,out);
 102                         }
 103                 l2c(tout0,iv);
 104                 l2c(tout1,iv);
 105                 }
 106         else
 107                 {
 108                 c2l(iv,xor0);
 109                 c2l(iv,xor1);
 110                 iv-=8;
 111                 for (l-=8; l>=0; l-=8)
 112                         {
 113                         c2l(in,tin0); tin[0]=tin0;
 114                         c2l(in,tin1); tin[1]=tin1;
 115                         RC2_decrypt(tin,ks);
 116                         tout0=tin[0]^xor0;
 117                         tout1=tin[1]^xor1;
 118                         l2c(tout0,out);
 119                         l2c(tout1,out);
 120                         xor0=tin0;
 121                         xor1=tin1;
 122                         }
 123                 if (l != -8)
 124                         {
 125                         c2l(in,tin0); tin[0]=tin0;
 126                         c2l(in,tin1); tin[1]=tin1;
 127                         RC2_decrypt(tin,ks);
 128                         tout0=tin[0]^xor0;
 129                         tout1=tin[1]^xor1;
 130                         l2cn(tout0,tout1,out,l+8);
 131                         xor0=tin0;
 132                         xor1=tin1;
 133                         }
 134                 l2c(xor0,iv);
 135                 l2c(xor1,iv);
 136                 }
 137         tin0=tin1=tout0=tout1=xor0=xor1=0;
 138         tin[0]=tin[1]=0;
 139         }
 140
 141 void RC2_encrypt(d,key)
 142 unsigned long *d;
 143 RC2_KEY *key;
 144         {
 145         int i,n;
 146         register RC2_INT *p0,*p1;
 147         register RC2_INT x0,x1,x2,x3,t;
 148         unsigned long l;
 149
 150         l=d[0];
 151         x0=(RC2_INT)l&0xffff;
 152         x1=(RC2_INT)(l>>16L);
 153         l=d[1];
 154         x2=(RC2_INT)l&0xffff;
 155         x3=(RC2_INT)(l>>16L);
 156
 157         n=3;
 158         i=5;
 159
 160         p0=p1= &(key->data[0]);
 161         for (;;)
 162                 {
 163                 t=(x0+(x1& ~x3)+(x2&x3)+ *(p0++))&0xffff;
 164                 x0=(t<<1)|(t>>15);
 165                 t=(x1+(x2& ~x0)+(x3&x0)+ *(p0++))&0xffff;
 166                 x1=(t<<2)|(t>>14);
 167                 t=(x2+(x3& ~x1)+(x0&x1)+ *(p0++))&0xffff;
 168                 x2=(t<<3)|(t>>13);
 169                 t=(x3+(x0& ~x2)+(x1&x2)+ *(p0++))&0xffff;
 170                 x3=(t<<5)|(t>>11);
 171
 172                 if (--i == 0)
 173                         {
 174                         if (--n == 0) break;
 175                         i=(n == 2)?6:5;
 176
 177                         x0+=p1[x3&0x3f];
 178                         x1+=p1[x0&0x3f];
 179                         x2+=p1[x1&0x3f];
 180                         x3+=p1[x2&0x3f];
 181                         }
 182                 }
 183
 184         d[0]=(unsigned long)(x0&0xffff)|((unsigned long)(x1&0xffff)<<16L);
 185         d[1]=(unsigned long)(x2&0xffff)|((unsigned long)(x3&0xffff)<<16L);
 186         }
 187
 188 void RC2_decrypt(d,key)
 189 unsigned long *d;
 190 RC2_KEY *key;
 191         {
 192         int i,n;
 193         register RC2_INT *p0,*p1;
 194         register RC2_INT x0,x1,x2,x3,t;
 195         unsigned long l;
 196
 197         l=d[0];
 198         x0=(RC2_INT)l&0xffff;
 199         x1=(RC2_INT)(l>>16L);
 200         l=d[1];
 201         x2=(RC2_INT)l&0xffff;
 202         x3=(RC2_INT)(l>>16L);
 203
 204         n=3;
 205         i=5;
 206
 207         p0= &(key->data[63]);
 208         p1= &(key->data[0]);
 209         for (;;)
 210                 {
 211                 t=((x3<<11)|(x3>>5))&0xffff;
 212                 x3=(t-(x0& ~x2)-(x1&x2)- *(p0--))&0xffff;
 213                 t=((x2<<13)|(x2>>3))&0xffff;
 214                 x2=(t-(x3& ~x1)-(x0&x1)- *(p0--))&0xffff;
 215                 t=((x1<<14)|(x1>>2))&0xffff;
 216                 x1=(t-(x2& ~x0)-(x3&x0)- *(p0--))&0xffff;
 217                 t=((x0<<15)|(x0>>1))&0xffff;
 218                 x0=(t-(x1& ~x3)-(x2&x3)- *(p0--))&0xffff;
 219
 220                 if (--i == 0)
 221                         {
 222                         if (--n == 0) break;
 223                         i=(n == 2)?6:5;
 224
 225                         x3=(x3-p1[x2&0x3f])&0xffff;
 226                         x2=(x2-p1[x1&0x3f])&0xffff;
 227                         x1=(x1-p1[x0&0x3f])&0xffff;
 228                         x0=(x0-p1[x3&0x3f])&0xffff;
 229                         }
 230                 }
 231
 232         d[0]=(unsigned long)(x0&0xffff)|((unsigned long)(x1&0xffff)<<16L);
 233         d[1]=(unsigned long)(x2&0xffff)|((unsigned long)(x3&0xffff)<<16L);
 234         }
 235