86 строки
2.1 KiB
C
86 строки
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* AES-128-CMAC with TLen 16 for IEEE 802.11w BIP
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* Copyright 2008, Jouni Malinen <j@w1.fi>
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*/
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/crypto.h>
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#include <linux/export.h>
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#include <linux/err.h>
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#include <crypto/aes.h>
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#include <net/mac80211.h>
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#include "key.h"
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#include "aes_cmac.h"
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#define CMAC_TLEN 8 /* CMAC TLen = 64 bits (8 octets) */
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#define CMAC_TLEN_256 16 /* CMAC TLen = 128 bits (16 octets) */
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#define AAD_LEN 20
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static const u8 zero[CMAC_TLEN_256];
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void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,
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const u8 *data, size_t data_len, u8 *mic)
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{
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SHASH_DESC_ON_STACK(desc, tfm);
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u8 out[AES_BLOCK_SIZE];
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const __le16 *fc;
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desc->tfm = tfm;
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crypto_shash_init(desc);
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crypto_shash_update(desc, aad, AAD_LEN);
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fc = (const __le16 *)aad;
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if (ieee80211_is_beacon(*fc)) {
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/* mask Timestamp field to zero */
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crypto_shash_update(desc, zero, 8);
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crypto_shash_update(desc, data + 8, data_len - 8 - CMAC_TLEN);
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} else {
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crypto_shash_update(desc, data, data_len - CMAC_TLEN);
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}
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crypto_shash_finup(desc, zero, CMAC_TLEN, out);
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memcpy(mic, out, CMAC_TLEN);
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}
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void ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad,
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const u8 *data, size_t data_len, u8 *mic)
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{
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SHASH_DESC_ON_STACK(desc, tfm);
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const __le16 *fc;
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desc->tfm = tfm;
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crypto_shash_init(desc);
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crypto_shash_update(desc, aad, AAD_LEN);
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fc = (const __le16 *)aad;
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if (ieee80211_is_beacon(*fc)) {
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/* mask Timestamp field to zero */
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crypto_shash_update(desc, zero, 8);
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crypto_shash_update(desc, data + 8,
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data_len - 8 - CMAC_TLEN_256);
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} else {
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crypto_shash_update(desc, data, data_len - CMAC_TLEN_256);
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}
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crypto_shash_finup(desc, zero, CMAC_TLEN_256, mic);
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}
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struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[],
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size_t key_len)
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{
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struct crypto_shash *tfm;
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tfm = crypto_alloc_shash("cmac(aes)", 0, 0);
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if (!IS_ERR(tfm))
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crypto_shash_setkey(tfm, key, key_len);
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return tfm;
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}
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void ieee80211_aes_cmac_key_free(struct crypto_shash *tfm)
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{
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crypto_free_shash(tfm);
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}
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