1214501Srpaulo/* 2214501Srpaulo * FIPS 186-2 PRF for internal crypto implementation 3214501Srpaulo * Copyright (c) 2006-2007, Jouni Malinen <j@w1.fi> 4214501Srpaulo * 5214501Srpaulo * This program is free software; you can redistribute it and/or modify 6214501Srpaulo * it under the terms of the GNU General Public License version 2 as 7214501Srpaulo * published by the Free Software Foundation. 8214501Srpaulo * 9214501Srpaulo * Alternatively, this software may be distributed under the terms of BSD 10214501Srpaulo * license. 11214501Srpaulo * 12214501Srpaulo * See README and COPYING for more details. 13214501Srpaulo */ 14214501Srpaulo 15214501Srpaulo#include "includes.h" 16214501Srpaulo 17214501Srpaulo#include "common.h" 18214501Srpaulo#include "sha1.h" 19214501Srpaulo#include "sha1_i.h" 20214501Srpaulo#include "crypto.h" 21214501Srpaulo 22214501Srpaulo 23214501Srpauloint fips186_2_prf(const u8 *seed, size_t seed_len, u8 *x, size_t xlen) 24214501Srpaulo{ 25214501Srpaulo u8 xkey[64]; 26214501Srpaulo u32 t[5], _t[5]; 27214501Srpaulo int i, j, m, k; 28214501Srpaulo u8 *xpos = x; 29214501Srpaulo u32 carry; 30214501Srpaulo 31214501Srpaulo if (seed_len > sizeof(xkey)) 32214501Srpaulo seed_len = sizeof(xkey); 33214501Srpaulo 34214501Srpaulo /* FIPS 186-2 + change notice 1 */ 35214501Srpaulo 36214501Srpaulo os_memcpy(xkey, seed, seed_len); 37214501Srpaulo os_memset(xkey + seed_len, 0, 64 - seed_len); 38214501Srpaulo t[0] = 0x67452301; 39214501Srpaulo t[1] = 0xEFCDAB89; 40214501Srpaulo t[2] = 0x98BADCFE; 41214501Srpaulo t[3] = 0x10325476; 42214501Srpaulo t[4] = 0xC3D2E1F0; 43214501Srpaulo 44214501Srpaulo m = xlen / 40; 45214501Srpaulo for (j = 0; j < m; j++) { 46214501Srpaulo /* XSEED_j = 0 */ 47214501Srpaulo for (i = 0; i < 2; i++) { 48214501Srpaulo /* XVAL = (XKEY + XSEED_j) mod 2^b */ 49214501Srpaulo 50214501Srpaulo /* w_i = G(t, XVAL) */ 51214501Srpaulo os_memcpy(_t, t, 20); 52214501Srpaulo SHA1Transform(_t, xkey); 53214501Srpaulo _t[0] = host_to_be32(_t[0]); 54214501Srpaulo _t[1] = host_to_be32(_t[1]); 55214501Srpaulo _t[2] = host_to_be32(_t[2]); 56214501Srpaulo _t[3] = host_to_be32(_t[3]); 57214501Srpaulo _t[4] = host_to_be32(_t[4]); 58214501Srpaulo os_memcpy(xpos, _t, 20); 59214501Srpaulo 60214501Srpaulo /* XKEY = (1 + XKEY + w_i) mod 2^b */ 61214501Srpaulo carry = 1; 62214501Srpaulo for (k = 19; k >= 0; k--) { 63214501Srpaulo carry += xkey[k] + xpos[k]; 64214501Srpaulo xkey[k] = carry & 0xff; 65214501Srpaulo carry >>= 8; 66214501Srpaulo } 67214501Srpaulo 68214501Srpaulo xpos += SHA1_MAC_LEN; 69214501Srpaulo } 70214501Srpaulo /* x_j = w_0|w_1 */ 71214501Srpaulo } 72214501Srpaulo 73214501Srpaulo return 0; 74214501Srpaulo} 75