2 * WPA Supplicant / EAP-PSK shared routines
3 * Copyright (c) 2004-2005, Jouni Malinen <jkmaline@cc.hut.fi>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Alternatively, this software may be distributed under the terms of BSD
12 * See README and COPYING for more details.
21 #include "eap_psk_common.h"
23 #define aes_block_size 16
26 void eap_psk_key_setup(const u8 *psk, u8 *ak, u8 *kdk)
28 memset(ak, 0, aes_block_size);
29 aes_128_encrypt_block(psk, ak, ak);
30 memcpy(kdk, ak, aes_block_size);
31 ak[aes_block_size - 1] ^= 0x01;
32 kdk[aes_block_size - 1] ^= 0x02;
33 aes_128_encrypt_block(psk, ak, ak);
34 aes_128_encrypt_block(psk, kdk, kdk);
38 void eap_psk_derive_keys(const u8 *kdk, const u8 *rand_p, u8 *tek, u8 *msk)
40 u8 hash[aes_block_size];
44 aes_128_encrypt_block(kdk, rand_p, hash);
46 hash[aes_block_size - 1] ^= counter;
47 aes_128_encrypt_block(kdk, hash, tek);
48 hash[aes_block_size - 1] ^= counter;
51 for (i = 0; i < EAP_PSK_MSK_LEN / aes_block_size; i++) {
52 hash[aes_block_size - 1] ^= counter;
53 aes_128_encrypt_block(kdk, hash, &msk[i * aes_block_size]);
54 hash[aes_block_size - 1] ^= counter;