blob: f9347d0df55e8eba9049f2e60518fe3ce5e67e5e [file] [log] [blame]
/*
* FIPS 186-2 PRF for internal crypto implementation
* Copyright (c) 2006-2007, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#include "common.h"
#include "sha1.h"
#include "sha1_i.h"
#include "crypto.h"
int fips186_2_prf(const u8 *seed, size_t seed_len, u8 *x, size_t xlen)
{
u8 xkey[64];
u32 _t[5];
int i, j, m, k;
u8 *xpos = x;
u32 carry;
struct SHA1Context ctx;
if (seed_len < sizeof(xkey))
os_memset(xkey + seed_len, 0, sizeof(xkey) - seed_len);
else
seed_len = sizeof(xkey);
/* FIPS 186-2 + change notice 1 */
os_memcpy(xkey, seed, seed_len);
SHA1Init(&ctx);
m = xlen / 40;
for (j = 0; j < m; j++) {
/* XSEED_j = 0 */
for (i = 0; i < 2; i++) {
/* XVAL = (XKEY + XSEED_j) mod 2^b */
/* w_i = G(t, XVAL) */
os_memcpy(_t, ctx.state, 20);
SHA1Transform(_t, xkey);
_t[0] = host_to_be32(_t[0]);
_t[1] = host_to_be32(_t[1]);
_t[2] = host_to_be32(_t[2]);
_t[3] = host_to_be32(_t[3]);
_t[4] = host_to_be32(_t[4]);
os_memcpy(xpos, _t, 20);
/* XKEY = (1 + XKEY + w_i) mod 2^b */
carry = 1;
for (k = 19; k >= 0; k--) {
carry += xkey[k] + xpos[k];
xkey[k] = carry & 0xff;
carry >>= 8;
}
xpos += SHA1_MAC_LEN;
}
/* x_j = w_0|w_1 */
}
return 0;
}