1 /*
2 * FIPS 186-2 PRF for libcrypto
3 * Copyright (c) 2004-2017, Jouni Malinen <j@w1.fi>
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9 #include "includes.h"
10 #include <wolfssl/options.h>
11 #include <wolfssl/wolfcrypt/sha.h>
12
13 #include "common.h"
14 #include "crypto.h"
15
16
sha1_transform(u32 * state,const u8 data[64])17 static void sha1_transform(u32 *state, const u8 data[64])
18 {
19 wc_Sha sha;
20
21 os_memset(&sha, 0, sizeof(sha));
22 sha.digest[0] = state[0];
23 sha.digest[1] = state[1];
24 sha.digest[2] = state[2];
25 sha.digest[3] = state[3];
26 sha.digest[4] = state[4];
27 wc_ShaUpdate(&sha, data, 64);
28 state[0] = sha.digest[0];
29 state[1] = sha.digest[1];
30 state[2] = sha.digest[2];
31 state[3] = sha.digest[3];
32 state[4] = sha.digest[4];
33 }
34
35
fips186_2_prf(const u8 * seed,size_t seed_len,u8 * x,size_t xlen)36 int fips186_2_prf(const u8 *seed, size_t seed_len, u8 *x, size_t xlen)
37 {
38 u8 xkey[64];
39 u32 t[5], _t[5];
40 int i, j, m, k;
41 u8 *xpos = x;
42 u32 carry;
43
44 if (seed_len < sizeof(xkey))
45 os_memset(xkey + seed_len, 0, sizeof(xkey) - seed_len);
46 else
47 seed_len = sizeof(xkey);
48
49 /* FIPS 186-2 + change notice 1 */
50
51 os_memcpy(xkey, seed, seed_len);
52 t[0] = 0x67452301;
53 t[1] = 0xEFCDAB89;
54 t[2] = 0x98BADCFE;
55 t[3] = 0x10325476;
56 t[4] = 0xC3D2E1F0;
57
58 m = xlen / 40;
59 for (j = 0; j < m; j++) {
60 /* XSEED_j = 0 */
61 for (i = 0; i < 2; i++) {
62 /* XVAL = (XKEY + XSEED_j) mod 2^b */
63
64 /* w_i = G(t, XVAL) */
65 os_memcpy(_t, t, 20);
66 sha1_transform(_t, xkey);
67 WPA_PUT_BE32(xpos, _t[0]);
68 WPA_PUT_BE32(xpos + 4, _t[1]);
69 WPA_PUT_BE32(xpos + 8, _t[2]);
70 WPA_PUT_BE32(xpos + 12, _t[3]);
71 WPA_PUT_BE32(xpos + 16, _t[4]);
72
73 /* XKEY = (1 + XKEY + w_i) mod 2^b */
74 carry = 1;
75 for (k = 19; k >= 0; k--) {
76 carry += xkey[k] + xpos[k];
77 xkey[k] = carry & 0xff;
78 carry >>= 8;
79 }
80
81 xpos += 20;
82 }
83 /* x_j = w_0|w_1 */
84 }
85
86 return 0;
87 }
88