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1 /*
2  * FIPS 186-2 PRF for libcrypto
3  * Copyright (c) 2004-2005, 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 <openssl/sha.h>
11 
12 #include "common.h"
13 #include "crypto.h"
14 
15 
sha1_transform(u32 * state,const u8 data[64])16 static void sha1_transform(u32 *state, const u8 data[64])
17 {
18 	SHA_CTX context;
19 	os_memset(&context, 0, sizeof(context));
20 #if defined(OPENSSL_IS_BORINGSSL) && !defined(ANDROID)
21 	context.h[0] = state[0];
22 	context.h[1] = state[1];
23 	context.h[2] = state[2];
24 	context.h[3] = state[3];
25 	context.h[4] = state[4];
26 	SHA1_Transform(&context, data);
27 	state[0] = context.h[0];
28 	state[1] = context.h[1];
29 	state[2] = context.h[2];
30 	state[3] = context.h[3];
31 	state[4] = context.h[4];
32 #else
33 	context.h0 = state[0];
34 	context.h1 = state[1];
35 	context.h2 = state[2];
36 	context.h3 = state[3];
37 	context.h4 = state[4];
38 	SHA1_Transform(&context, data);
39 	state[0] = context.h0;
40 	state[1] = context.h1;
41 	state[2] = context.h2;
42 	state[3] = context.h3;
43 	state[4] = context.h4;
44 #endif
45 }
46 
47 
fips186_2_prf(const u8 * seed,size_t seed_len,u8 * x,size_t xlen)48 int fips186_2_prf(const u8 *seed, size_t seed_len, u8 *x, size_t xlen)
49 {
50 	u8 xkey[64];
51 	u32 t[5], _t[5];
52 	int i, j, m, k;
53 	u8 *xpos = x;
54 	u32 carry;
55 
56 	if (seed_len < sizeof(xkey))
57 		os_memset(xkey + seed_len, 0, sizeof(xkey) - seed_len);
58 	else
59 		seed_len = sizeof(xkey);
60 
61 	/* FIPS 186-2 + change notice 1 */
62 
63 	os_memcpy(xkey, seed, seed_len);
64 	t[0] = 0x67452301;
65 	t[1] = 0xEFCDAB89;
66 	t[2] = 0x98BADCFE;
67 	t[3] = 0x10325476;
68 	t[4] = 0xC3D2E1F0;
69 
70 	m = xlen / 40;
71 	for (j = 0; j < m; j++) {
72 		/* XSEED_j = 0 */
73 		for (i = 0; i < 2; i++) {
74 			/* XVAL = (XKEY + XSEED_j) mod 2^b */
75 
76 			/* w_i = G(t, XVAL) */
77 			os_memcpy(_t, t, 20);
78 			sha1_transform(_t, xkey);
79 			WPA_PUT_BE32(xpos, _t[0]);
80 			WPA_PUT_BE32(xpos + 4, _t[1]);
81 			WPA_PUT_BE32(xpos + 8, _t[2]);
82 			WPA_PUT_BE32(xpos + 12, _t[3]);
83 			WPA_PUT_BE32(xpos + 16, _t[4]);
84 
85 			/* XKEY = (1 + XKEY + w_i) mod 2^b */
86 			carry = 1;
87 			for (k = 19; k >= 0; k--) {
88 				carry += xkey[k] + xpos[k];
89 				xkey[k] = carry & 0xff;
90 				carry >>= 8;
91 			}
92 
93 			xpos += 20;
94 		}
95 		/* x_j = w_0|w_1 */
96 	}
97 
98 	return 0;
99 }
100