workbench/network/WirelessManager/src/crypto/fips_prf_internal.c

   1 /*
   2  * FIPS 186-2 PRF for internal crypto implementation
   3  * Copyright (c) 2006-2007, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16
  17 #include "common.h"
  18 #include "sha1.h"
  19 #include "sha1_i.h"
  20 #include "crypto.h"
  21
  22
  23 int fips186_2_prf(const u8 *seed, size_t seed_len, u8 *x, size_t xlen)
  24 {
  25         u8 xkey[64];
  26         u32 t[5], _t[5];
  27         int i, j, m, k;
  28         u8 *xpos = x;
  29         u32 carry;
  30
  31         if (seed_len > sizeof(xkey))
  32                 seed_len = sizeof(xkey);
  33
  34         /* FIPS 186-2 + change notice 1 */
  35
  36         os_memcpy(xkey, seed, seed_len);
  37         os_memset(xkey + seed_len, 0, 64 - seed_len);
  38         t[0] = 0x67452301;
  39         t[1] = 0xEFCDAB89;
  40         t[2] = 0x98BADCFE;
  41         t[3] = 0x10325476;
  42         t[4] = 0xC3D2E1F0;
  43
  44         m = xlen / 40;
  45         for (j = 0; j < m; j++) {
  46                 /* XSEED_j = 0 */
  47                 for (i = 0; i < 2; i++) {
  48                         /* XVAL = (XKEY + XSEED_j) mod 2^b */
  49
  50                         /* w_i = G(t, XVAL) */
  51                         os_memcpy(_t, t, 20);
  52                         SHA1Transform(_t, xkey);
  53                         _t[0] = host_to_be32(_t[0]);
  54                         _t[1] = host_to_be32(_t[1]);
  55                         _t[2] = host_to_be32(_t[2]);
  56                         _t[3] = host_to_be32(_t[3]);
  57                         _t[4] = host_to_be32(_t[4]);
  58                         os_memcpy(xpos, _t, 20);
  59
  60                         /* XKEY = (1 + XKEY + w_i) mod 2^b */
  61                         carry = 1;
  62                         for (k = 19; k >= 0; k--) {
  63                                 carry += xkey[k] + xpos[k];
  64                                 xkey[k] = carry & 0xff;
  65                                 carry >>= 8;
  66                         }
  67
  68                         xpos += SHA1_MAC_LEN;
  69                 }
  70                 /* x_j = w_0|w_1 */
  71         }
  72
  73         return 0;
  74 }