release/src/router/openssl/crypto/des/cfb_enc.c

   1 /* crypto/des/cfb_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 "e_os.h"
  60 #include "des_locl.h"
  61 #include <assert.h>
  62
  63 /* The input and output are loaded in multiples of 8 bits.
  64  * What this means is that if you hame numbits=12 and length=2
  65  * the first 12 bits will be retrieved from the first byte and half
  66  * the second.  The second 12 bits will come from the 3rd and half the 4th
  67  * byte.
  68  */
  69 /* Until Aug 1 2003 this function did not correctly implement CFB-r, so it
  70  * will not be compatible with any encryption prior to that date. Ben. */
  71 void DES_cfb_encrypt(const unsigned char *in, unsigned char *out, int numbits,
  72                      long length, DES_key_schedule *schedule, DES_cblock *ivec,
  73                      int enc)
  74         {
  75         register DES_LONG d0,d1,v0,v1;
  76         register unsigned long l=length;
  77         register int num=numbits/8,n=(numbits+7)/8,i,rem=numbits%8;
  78         DES_LONG ti[2];
  79         unsigned char *iv;
  80 #ifndef L_ENDIAN
  81         unsigned char ovec[16];
  82 #else
  83         unsigned int  sh[4];
  84         unsigned char *ovec=(unsigned char *)sh;
  85
  86         /* I kind of count that compiler optimizes away this assertioni,*/
  87         assert (sizeof(sh[0])==4);      /* as this holds true for all,  */
  88                                         /* but 16-bit platforms...      */
  89
  90 #endif
  91
  92         if (numbits<=0 || numbits > 64) return;
  93         iv = &(*ivec)[0];
  94         c2l(iv,v0);
  95         c2l(iv,v1);
  96         if (enc)
  97                 {
  98                 while (l >= (unsigned long)n)
  99                         {
 100                         l-=n;
 101                         ti[0]=v0;
 102                         ti[1]=v1;
 103                         DES_encrypt1((DES_LONG *)ti,schedule,DES_ENCRYPT);
 104                         c2ln(in,d0,d1,n);
 105                         in+=n;
 106                         d0^=ti[0];
 107                         d1^=ti[1];
 108                         l2cn(d0,d1,out,n);
 109                         out+=n;
 110                         /* 30-08-94 - eay - changed because l>>32 and
 111                          * l<<32 are bad under gcc :-( */
 112                         if (numbits == 32)
 113                                 { v0=v1; v1=d0; }
 114                         else if (numbits == 64)
 115                                 { v0=d0; v1=d1; }
 116                         else
 117                                 {
 118 #ifndef L_ENDIAN
 119                                 iv=&ovec[0];
 120                                 l2c(v0,iv);
 121                                 l2c(v1,iv);
 122                                 l2c(d0,iv);
 123                                 l2c(d1,iv);
 124 #else
 125                                 sh[0]=v0, sh[1]=v1, sh[2]=d0, sh[3]=d1;
 126 #endif
 127                                 if (rem==0)
 128                                         memmove(ovec,ovec+num,8);
 129                                 else
 130                                         for(i=0 ; i < 8 ; ++i)
 131                                                 ovec[i]=ovec[i+num]<<rem |
 132                                                         ovec[i+num+1]>>(8-rem);
 133 #ifdef L_ENDIAN
 134                                 v0=sh[0], v1=sh[1];
 135 #else
 136                                 iv=&ovec[0];
 137                                 c2l(iv,v0);
 138                                 c2l(iv,v1);
 139 #endif
 140                                 }
 141                         }
 142                 }
 143         else
 144                 {
 145                 while (l >= (unsigned long)n)
 146                         {
 147                         l-=n;
 148                         ti[0]=v0;
 149                         ti[1]=v1;
 150                         DES_encrypt1((DES_LONG *)ti,schedule,DES_ENCRYPT);
 151                         c2ln(in,d0,d1,n);
 152                         in+=n;
 153                         /* 30-08-94 - eay - changed because l>>32 and
 154                          * l<<32 are bad under gcc :-( */
 155                         if (numbits == 32)
 156                                 { v0=v1; v1=d0; }
 157                         else if (numbits == 64)
 158                                 { v0=d0; v1=d1; }
 159                         else
 160                                 {
 161 #ifndef L_ENDIAN
 162                                 iv=&ovec[0];
 163                                 l2c(v0,iv);
 164                                 l2c(v1,iv);
 165                                 l2c(d0,iv);
 166                                 l2c(d1,iv);
 167 #else
 168                                 sh[0]=v0, sh[1]=v1, sh[2]=d0, sh[3]=d1;
 169 #endif
 170                                 if (rem==0)
 171                                         memmove(ovec,ovec+num,8);
 172                                 else
 173                                         for(i=0 ; i < 8 ; ++i)
 174                                                 ovec[i]=ovec[i+num]<<rem |
 175                                                         ovec[i+num+1]>>(8-rem);
 176 #ifdef L_ENDIAN
 177                                 v0=sh[0], v1=sh[1];
 178 #else
 179                                 iv=&ovec[0];
 180                                 c2l(iv,v0);
 181                                 c2l(iv,v1);
 182 #endif
 183                                 }
 184                         d0^=ti[0];
 185                         d1^=ti[1];
 186                         l2cn(d0,d1,out,n);
 187                         out+=n;
 188                         }
 189                 }
 190         iv = &(*ivec)[0];
 191         l2c(v0,iv);
 192         l2c(v1,iv);
 193         v0=v1=d0=d1=ti[0]=ti[1]=0;
 194         }
 195