mirror of
https://github.com/vanhoefm/fragattacks.git
synced 2024-12-01 19:58:22 -05:00
a9ea17491a
Explicitly validate seed_len to skip memset call with zero length of copied data at the end of the buffer. This is not really needed, but it makes the code a bit easier for static analyzers. Signed-hostap: Jouni Malinen <j@w1.fi>
76 lines
1.6 KiB
C
76 lines
1.6 KiB
C
/*
|
|
* FIPS 186-2 PRF for internal crypto implementation
|
|
* Copyright (c) 2006-2007, Jouni Malinen <j@w1.fi>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* Alternatively, this software may be distributed under the terms of BSD
|
|
* license.
|
|
*
|
|
* See README and COPYING 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], _t[5];
|
|
int i, j, m, k;
|
|
u8 *xpos = x;
|
|
u32 carry;
|
|
|
|
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);
|
|
t[0] = 0x67452301;
|
|
t[1] = 0xEFCDAB89;
|
|
t[2] = 0x98BADCFE;
|
|
t[3] = 0x10325476;
|
|
t[4] = 0xC3D2E1F0;
|
|
|
|
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, t, 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;
|
|
}
|