44 lines
1.1 KiB
C
44 lines
1.1 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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* Copyright (C) 2020 Intel Corporation
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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/export.h>
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#include <linux/err.h>
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#include <crypto/aes-cbc-macs.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 AAD_LEN 20
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static const u8 zero[IEEE80211_CMAC_256_MIC_LEN];
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void ieee80211_aes_cmac(const struct aes_cmac_key *key, const u8 *aad,
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const u8 *data, size_t data_len, u8 *mic,
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unsigned int mic_len)
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{
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struct aes_cmac_ctx ctx;
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u8 out[AES_BLOCK_SIZE];
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const __le16 *fc;
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aes_cmac_init(&ctx, key);
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aes_cmac_update(&ctx, 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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aes_cmac_update(&ctx, zero, 8);
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aes_cmac_update(&ctx, data + 8, data_len - 8 - mic_len);
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} else {
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aes_cmac_update(&ctx, data, data_len - mic_len);
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}
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aes_cmac_update(&ctx, zero, mic_len);
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aes_cmac_final(&ctx, out);
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memcpy(mic, out, mic_len);
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}
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