crypto/rc5/rc5_skey.c

   1 /*
   2  * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 /*
  11  * RC5 low level APIs are deprecated for public use, but still ok for internal
  12  * use.
  13  */
  14 #include "internal/deprecated.h"
  15
  16 #include <openssl/rc5.h>
  17 #include "rc5_local.h"
  18
  19 int RC5_32_set_key(RC5_32_KEY *key, int len, const unsigned char *data,
  20                    int rounds)
  21 {
  22     RC5_32_INT L[64], l, ll, A, B, *S, k;
  23     int i, j, m, c, t, ii, jj;
  24
  25     if (len > 255)
  26         return 0;
  27
  28     if ((rounds != RC5_16_ROUNDS) &&
  29         (rounds != RC5_12_ROUNDS) && (rounds != RC5_8_ROUNDS))
  30         rounds = RC5_16_ROUNDS;
  31
  32     key->rounds = rounds;
  33     S = &(key->data[0]);
  34     j = 0;
  35     for (i = 0; i <= (len - 8); i += 8) {
  36         c2l(data, l);
  37         L[j++] = l;
  38         c2l(data, l);
  39         L[j++] = l;
  40     }
  41     ii = len - i;
  42     if (ii) {
  43         k = len & 0x07;
  44         c2ln(data, l, ll, k);
  45         L[j + 0] = l;
  46         L[j + 1] = ll;
  47     }
  48
  49     c = (len + 3) / 4;
  50     t = (rounds + 1) * 2;
  51     S[0] = RC5_32_P;
  52     for (i = 1; i < t; i++)
  53         S[i] = (S[i - 1] + RC5_32_Q) & RC5_32_MASK;
  54
  55     j = (t > c) ? t : c;
  56     j *= 3;
  57     ii = jj = 0;
  58     A = B = 0;
  59     for (i = 0; i < j; i++) {
  60         k = (S[ii] + A + B) & RC5_32_MASK;
  61         A = S[ii] = ROTATE_l32(k, 3);
  62         m = (int)(A + B);
  63         k = (L[jj] + A + B) & RC5_32_MASK;
  64         B = L[jj] = ROTATE_l32(k, m);
  65         if (++ii >= t)
  66             ii = 0;
  67         if (++jj >= c)
  68             jj = 0;
  69     }
  70
  71     return 1;
  72 }