2 * EAP server/peer: EAP-PSK shared routines
3 * Copyright (c) 2004-2006, Jouni Malinen <j@w1.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.
18 #include "crypto/aes_wrap.h"
20 #include "eap_psk_common.h"
22 #define aes_block_size 16
25 int eap_psk_key_setup(const u8 *psk, u8 *ak, u8 *kdk)
27 os_memset(ak, 0, aes_block_size);
28 if (aes_128_encrypt_block(psk, ak, ak))
30 os_memcpy(kdk, ak, aes_block_size);
31 ak[aes_block_size - 1] ^= 0x01;
32 kdk[aes_block_size - 1] ^= 0x02;
33 if (aes_128_encrypt_block(psk, ak, ak) ||
34 aes_128_encrypt_block(psk, kdk, kdk))
40 int eap_psk_derive_keys(const u8 *kdk, const u8 *rand_p, u8 *tek, u8 *msk,
43 u8 hash[aes_block_size];
47 if (aes_128_encrypt_block(kdk, rand_p, hash))
50 hash[aes_block_size - 1] ^= counter;
51 if (aes_128_encrypt_block(kdk, hash, tek))
53 hash[aes_block_size - 1] ^= counter;
56 for (i = 0; i < EAP_MSK_LEN / aes_block_size; i++) {
57 hash[aes_block_size - 1] ^= counter;
58 if (aes_128_encrypt_block(kdk, hash, &msk[i * aes_block_size]))
60 hash[aes_block_size - 1] ^= counter;
64 for (i = 0; i < EAP_EMSK_LEN / aes_block_size; i++) {
65 hash[aes_block_size - 1] ^= counter;
66 if (aes_128_encrypt_block(kdk, hash,
67 &emsk[i * aes_block_size]))
69 hash[aes_block_size - 1] ^= counter;