Line data    Source code

       1             : /* crypto/des/cfb64enc.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 "des_locl.h"
      60             : 
      61             : /*
      62             :  * The input and output encrypted as though 64bit cfb mode is being used.
      63             :  * The extra state information to record how much of the 64bit block we have
      64             :  * used is contained in *num;
      65             :  */
      66             : 
      67           0 : void DES_cfb64_encrypt(const unsigned char *in, unsigned char *out,
      68             :                        long length, DES_key_schedule *schedule,
      69             :                        DES_cblock *ivec, int *num, int enc)
      70             : {
      71             :     register DES_LONG v0, v1;
      72             :     register long l = length;
      73           0 :     register int n = *num;
      74             :     DES_LONG ti[2];
      75             :     unsigned char *iv, c, cc;
      76             : 
      77           0 :     iv = &(*ivec)[0];
      78           0 :     if (enc) {
      79           0 :         while (l--) {
      80           0 :             if (n == 0) {
      81           0 :                 c2l(iv, v0);
      82           0 :                 ti[0] = v0;
      83           0 :                 c2l(iv, v1);
      84           0 :                 ti[1] = v1;
      85           0 :                 DES_encrypt1(ti, schedule, DES_ENCRYPT);
      86             :                 iv = &(*ivec)[0];
      87           0 :                 v0 = ti[0];
      88           0 :                 l2c(v0, iv);
      89           0 :                 v0 = ti[1];
      90           0 :                 l2c(v0, iv);
      91             :                 iv = &(*ivec)[0];
      92             :             }
      93           0 :             c = *(in++) ^ iv[n];
      94           0 :             *(out++) = c;
      95           0 :             iv[n] = c;
      96           0 :             n = (n + 1) & 0x07;
      97             :         }
      98             :     } else {
      99           0 :         while (l--) {
     100           0 :             if (n == 0) {
     101           0 :                 c2l(iv, v0);
     102           0 :                 ti[0] = v0;
     103           0 :                 c2l(iv, v1);
     104           0 :                 ti[1] = v1;
     105           0 :                 DES_encrypt1(ti, schedule, DES_ENCRYPT);
     106             :                 iv = &(*ivec)[0];
     107           0 :                 v0 = ti[0];
     108           0 :                 l2c(v0, iv);
     109           0 :                 v0 = ti[1];
     110           0 :                 l2c(v0, iv);
     111             :                 iv = &(*ivec)[0];
     112             :             }
     113           0 :             cc = *(in++);
     114           0 :             c = iv[n];
     115           0 :             iv[n] = cc;
     116           0 :             *(out++) = c ^ cc;
     117           0 :             n = (n + 1) & 0x07;
     118             :         }
     119             :     }
     120             :     v0 = v1 = ti[0] = ti[1] = c = cc = 0;
     121           0 :     *num = n;
     122           0 : }