crypto/rc5/rc5_skey.c

   1 /* crypto/rc5/rc5_skey.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/rc5.h>
  60 #include "rc5_locl.h"
  61
  62 void RC5_32_set_key(RC5_32_KEY *key, int len, const unsigned char *data,
  63                     int rounds)
  64 {
  65     RC5_32_INT L[64], l, ll, A, B, *S, k;
  66     int i, j, m, c, t, ii, jj;
  67
  68     if ((rounds != RC5_16_ROUNDS) &&
  69         (rounds != RC5_12_ROUNDS) && (rounds != RC5_8_ROUNDS))
  70         rounds = RC5_16_ROUNDS;
  71
  72     key->rounds = rounds;
  73     S = &(key->data[0]);
  74     j = 0;
  75     for (i = 0; i <= (len - 8); i += 8) {
  76         c2l(data, l);
  77         L[j++] = l;
  78         c2l(data, l);
  79         L[j++] = l;
  80     }
  81     ii = len - i;
  82     if (ii) {
  83         k = len & 0x07;
  84         c2ln(data, l, ll, k);
  85         L[j + 0] = l;
  86         L[j + 1] = ll;
  87     }
  88
  89     c = (len + 3) / 4;
  90     t = (rounds + 1) * 2;
  91     S[0] = RC5_32_P;
  92     for (i = 1; i < t; i++)
  93         S[i] = (S[i - 1] + RC5_32_Q) & RC5_32_MASK;
  94
  95     j = (t > c) ? t : c;
  96     j *= 3;
  97     ii = jj = 0;
  98     A = B = 0;
  99     for (i = 0; i < j; i++) {
 100         k = (S[ii] + A + B) & RC5_32_MASK;
 101         A = S[ii] = ROTATE_l32(k, 3);
 102         m = (int)(A + B);
 103         k = (L[jj] + A + B) & RC5_32_MASK;
 104         B = L[jj] = ROTATE_l32(k, m);
 105         if (++ii >= t)
 106             ii = 0;
 107         if (++jj >= c)
 108             jj = 0;
 109     }
 110 }