fips_prf_openssl.c
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00001 /*
00002  * FIPS 186-2 PRF for libcrypto
00003  * Copyright (c) 2004-2005, Jouni Malinen <j@w1.fi>
00004  *
00005  * This program is free software; you can redistribute it and/or modify
00006  * it under the terms of the GNU General Public License version 2 as
00007  * published by the Free Software Foundation.
00008  *
00009  * Alternatively, this software may be distributed under the terms of BSD
00010  * license.
00011  *
00012  * See README and COPYING for more details.
00013  */
00014 
00015 #include "includes.h"
00016 #include <openssl/sha.h>
00017 
00018 #include "common.h"
00019 #include "crypto.h"
00020 
00021 
00022 static void sha1_transform(u8 *state, const u8 data[64])
00023 {
00024         SHA_CTX context;
00025         os_memset(&context, 0, sizeof(context));
00026         os_memcpy(&context.h0, state, 5 * 4);
00027         SHA1_Transform(&context, data);
00028         os_memcpy(state, &context.h0, 5 * 4);
00029 }
00030 
00031 
00032 int fips186_2_prf(const u8 *seed, size_t seed_len, u8 *x, size_t xlen)
00033 {
00034         u8 xkey[64];
00035         u32 t[5], _t[5];
00036         int i, j, m, k;
00037         u8 *xpos = x;
00038         u32 carry;
00039 
00040         if (seed_len > sizeof(xkey))
00041                 seed_len = sizeof(xkey);
00042 
00043         /* FIPS 186-2 + change notice 1 */
00044 
00045         os_memcpy(xkey, seed, seed_len);
00046         os_memset(xkey + seed_len, 0, 64 - seed_len);
00047         t[0] = 0x67452301;
00048         t[1] = 0xEFCDAB89;
00049         t[2] = 0x98BADCFE;
00050         t[3] = 0x10325476;
00051         t[4] = 0xC3D2E1F0;
00052 
00053         m = xlen / 40;
00054         for (j = 0; j < m; j++) {
00055                 /* XSEED_j = 0 */
00056                 for (i = 0; i < 2; i++) {
00057                         /* XVAL = (XKEY + XSEED_j) mod 2^b */
00058 
00059                         /* w_i = G(t, XVAL) */
00060                         os_memcpy(_t, t, 20);
00061                         sha1_transform((u8 *) _t, xkey);
00062                         _t[0] = host_to_be32(_t[0]);
00063                         _t[1] = host_to_be32(_t[1]);
00064                         _t[2] = host_to_be32(_t[2]);
00065                         _t[3] = host_to_be32(_t[3]);
00066                         _t[4] = host_to_be32(_t[4]);
00067                         os_memcpy(xpos, _t, 20);
00068 
00069                         /* XKEY = (1 + XKEY + w_i) mod 2^b */
00070                         carry = 1;
00071                         for (k = 19; k >= 0; k--) {
00072                                 carry += xkey[k] + xpos[k];
00073                                 xkey[k] = carry & 0xff;
00074                                 carry >>= 8;
00075                         }
00076 
00077                         xpos += 20;
00078                 }
00079                 /* x_j = w_0|w_1 */
00080         }
00081 
00082         return 0;
00083 }


wpa_supplicant_node
Author(s): Package maintained by Blaise Gassend
autogenerated on Thu Apr 24 2014 15:33:20