cd92f7f98a
The initialization values used for the FIPS 186-2 PRF are identical to the ones used in SHA1Init(), so use that internal function instead of maintaining a duplicate set of values here. fips186_2_prf() was already using an internal SHA1Transform() function so using another internal function does not make this any worse. Signed-off-by: Jouni Malinen <j@w1.fi>
66 lines
1.3 KiB
C
66 lines
1.3 KiB
C
/*
|
|
* 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;
|
|
}
|