crypto/rc2/rc2ofb64.c

   1 /* crypto/rc2/rc2ofb64.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 <openssl/rc2.h>
  60 #include "rc2_locl.h"
  61
  62 /*
  63  * The input and output encrypted as though 64bit ofb mode is being used.
  64  * The extra state information to record how much of the 64bit block we have
  65  * used is contained in *num;
  66  */
  67 void RC2_ofb64_encrypt(const unsigned char *in, unsigned char *out,
  68                        long length, RC2_KEY *schedule, unsigned char *ivec,
  69                        int *num)
  70 {
  71     register unsigned long v0, v1, t;
  72     register int n = *num;
  73     register long l = length;
  74     unsigned char d[8];
  75     register char *dp;
  76     unsigned long ti[2];
  77     unsigned char *iv;
  78     int save = 0;
  79
  80     iv = (unsigned char *)ivec;
  81     c2l(iv, v0);
  82     c2l(iv, v1);
  83     ti[0] = v0;
  84     ti[1] = v1;
  85     dp = (char *)d;
  86     l2c(v0, dp);
  87     l2c(v1, dp);
  88     while (l--) {
  89         if (n == 0) {
  90             RC2_encrypt((unsigned long *)ti, schedule);
  91             dp = (char *)d;
  92             t = ti[0];
  93             l2c(t, dp);
  94             t = ti[1];
  95             l2c(t, dp);
  96             save++;
  97         }
  98         *(out++) = *(in++) ^ d[n];
  99         n = (n + 1) & 0x07;
 100     }
 101     if (save) {
 102         v0 = ti[0];
 103         v1 = ti[1];
 104         iv = (unsigned char *)ivec;
 105         l2c(v0, iv);
 106         l2c(v1, iv);
 107     }
 108     t = v0 = v1 = ti[0] = ti[1] = 0;
 109     *num = n;
 110 }