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* EAP server/peer: EAP-PSK shared routines
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* Copyright (c) 2004-2006, Jouni Malinen <j@w1.fi>
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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* Alternatively, this software may be distributed under the terms of BSD
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* See README and COPYING for more details.
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#include "eap_psk_common.h"
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#define aes_block_size 16
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void eap_psk_key_setup(const u8 *psk, u8 *ak, u8 *kdk)
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os_memset(ak, 0, aes_block_size);
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aes_128_encrypt_block(psk, ak, ak);
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os_memcpy(kdk, ak, aes_block_size);
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ak[aes_block_size - 1] ^= 0x01;
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kdk[aes_block_size - 1] ^= 0x02;
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aes_128_encrypt_block(psk, ak, ak);
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aes_128_encrypt_block(psk, kdk, kdk);
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void eap_psk_derive_keys(const u8 *kdk, const u8 *rand_p, u8 *tek, u8 *msk,
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u8 hash[aes_block_size];
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aes_128_encrypt_block(kdk, rand_p, hash);
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hash[aes_block_size - 1] ^= counter;
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aes_128_encrypt_block(kdk, hash, tek);
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hash[aes_block_size - 1] ^= counter;
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for (i = 0; i < EAP_MSK_LEN / aes_block_size; i++) {
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hash[aes_block_size - 1] ^= counter;
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aes_128_encrypt_block(kdk, hash, &msk[i * aes_block_size]);
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hash[aes_block_size - 1] ^= counter;
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for (i = 0; i < EAP_EMSK_LEN / aes_block_size; i++) {
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hash[aes_block_size - 1] ^= counter;
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aes_128_encrypt_block(kdk, hash, &emsk[i * aes_block_size]);
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hash[aes_block_size - 1] ^= counter;