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      1 /*
      2  * FIPS 186-2 PRF for libcrypto
      3  * Copyright (c) 2004-2005, Jouni Malinen <j (at) 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 
     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 
     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