crypto/des/ofb64ede.c

   1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   2  * All rights reserved.
   3  *
   4  * This package is an SSL implementation written
   5  * by Eric Young (eay@cryptsoft.com).
   6  * The implementation was written so as to conform with Netscapes SSL.
   7  *
   8  * This library is free for commercial and non-commercial use as long as
   9  * the following conditions are aheared to.  The following conditions
  10  * apply to all code found in this distribution, be it the RC4, RSA,
  11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  12  * included with this distribution is covered by the same copyright terms
  13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  14  *
  15  * Copyright remains Eric Young's, and as such any Copyright notices in
  16  * the code are not to be removed.
  17  * If this package is used in a product, Eric Young should be given attribution
  18  * as the author of the parts of the library used.
  19  * This can be in the form of a textual message at program startup or
  20  * in documentation (online or textual) provided with the package.
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  * 1. Redistributions of source code must retain the copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  * 2. Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in the
  29  *    documentation and/or other materials provided with the distribution.
  30  * 3. All advertising materials mentioning features or use of this software
  31  *    must display the following acknowledgement:
  32  *    "This product includes cryptographic software written by
  33  *     Eric Young (eay@cryptsoft.com)"
  34  *    The word 'cryptographic' can be left out if the rouines from the library
  35  *    being used are not cryptographic related :-).
  36  * 4. If you include any Windows specific code (or a derivative thereof) from
  37  *    the apps directory (application code) you must include an acknowledgement:
  38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  50  * SUCH DAMAGE.
  51  *
  52  * The licence and distribution terms for any publically available version or
  53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  54  * copied and put under another distribution licence
  55  * [including the GNU Public Licence.]
  56  */
  57
  58 #include "des_locl.h"
  59
  60 /*
  61  * The input and output encrypted as though 64bit ofb mode is being used.
  62  * The extra state information to record how much of the 64bit block we have
  63  * used is contained in *num;
  64  */
  65 void DES_ede3_ofb64_encrypt(register const unsigned char *in,
  66                             register unsigned char *out, long length,
  67                             DES_key_schedule *k1, DES_key_schedule *k2,
  68                             DES_key_schedule *k3, DES_cblock *ivec, int *num)
  69 {
  70     register DES_LONG v0, v1;
  71     register int n = *num;
  72     register long l = length;
  73     DES_cblock d;
  74     register char *dp;
  75     DES_LONG ti[2];
  76     unsigned char *iv;
  77     int save = 0;
  78
  79     iv = &(*ivec)[0];
  80     c2l(iv, v0);
  81     c2l(iv, v1);
  82     ti[0] = v0;
  83     ti[1] = v1;
  84     dp = (char *)d;
  85     l2c(v0, dp);
  86     l2c(v1, dp);
  87     while (l--) {
  88         if (n == 0) {
  89             /* ti[0]=v0; */
  90             /* ti[1]=v1; */
  91             DES_encrypt3(ti, k1, k2, k3);
  92             v0 = ti[0];
  93             v1 = ti[1];
  94
  95             dp = (char *)d;
  96             l2c(v0, dp);
  97             l2c(v1, dp);
  98             save++;
  99         }
 100         *(out++) = *(in++) ^ d[n];
 101         n = (n + 1) & 0x07;
 102     }
 103     if (save) {
 104         iv = &(*ivec)[0];
 105         l2c(v0, iv);
 106         l2c(v1, iv);
 107     }
 108     v0 = v1 = ti[0] = ti[1] = 0;
 109     *num = n;
 110 }