2 * EAP server/peer: EAP-PSK shared routines
3 * Copyright (c) 2004-2006, Jouni Malinen <j@w1.fi>
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
12 #include "crypto/aes_wrap.h"
14 #include "eap_psk_common.h"
16 #define aes_block_size 16
19 int eap_psk_key_setup(const u8 *psk, u8 *ak, u8 *kdk)
21 os_memset(ak, 0, aes_block_size);
22 if (aes_128_encrypt_block(psk, ak, ak))
24 os_memcpy(kdk, ak, aes_block_size);
25 ak[aes_block_size - 1] ^= 0x01;
26 kdk[aes_block_size - 1] ^= 0x02;
27 if (aes_128_encrypt_block(psk, ak, ak) ||
28 aes_128_encrypt_block(psk, kdk, kdk))
34 int eap_psk_derive_keys(const u8 *kdk, const u8 *rand_p, u8 *tek, u8 *msk,
37 u8 hash[aes_block_size];
41 if (aes_128_encrypt_block(kdk, rand_p, hash))
44 hash[aes_block_size - 1] ^= counter;
45 if (aes_128_encrypt_block(kdk, hash, tek))
47 hash[aes_block_size - 1] ^= counter;
50 for (i = 0; i < EAP_MSK_LEN / aes_block_size; i++) {
51 hash[aes_block_size - 1] ^= counter;
52 if (aes_128_encrypt_block(kdk, hash, &msk[i * aes_block_size]))
54 hash[aes_block_size - 1] ^= counter;
58 for (i = 0; i < EAP_EMSK_LEN / aes_block_size; i++) {
59 hash[aes_block_size - 1] ^= counter;
60 if (aes_128_encrypt_block(kdk, hash,
61 &emsk[i * aes_block_size]))
63 hash[aes_block_size - 1] ^= counter;