// SPDX-License-Identifier: GPL-2.0-only

  /*
   * AES-128-CMAC with TLen 16 for IEEE 802.11w BIP
   * Copyright 2008, Jouni Malinen <j@w1.fi>

   */
  
  #include <linux/kernel.h>
  #include <linux/types.h>
  #include <linux/crypto.h>

  #include <linux/export.h>

  #include <linux/err.h>

  #include <crypto/aes.h>

  
  #include <net/mac80211.h>
  #include "key.h"
  #include "aes_cmac.h"

  #define CMAC_TLEN 8 /* CMAC TLen = 64 bits (8 octets) */

  #define CMAC_TLEN_256 16 /* CMAC TLen = 128 bits (16 octets) */

  #define AAD_LEN 20

  static const u8 zero[CMAC_TLEN_256];

  void ieee80211_aes_cmac(struct crypto_shash *tfm, const u8 *aad,

  			const u8 *data, size_t data_len, u8 *mic)
  {

  	SHASH_DESC_ON_STACK(desc, tfm);
  	u8 out[AES_BLOCK_SIZE];

  	desc->tfm = tfm;

  	crypto_shash_init(desc);
  	crypto_shash_update(desc, aad, AAD_LEN);
  	crypto_shash_update(desc, data, data_len - CMAC_TLEN);
  	crypto_shash_finup(desc, zero, CMAC_TLEN, out);
  
  	memcpy(mic, out, CMAC_TLEN);

  }

  void ieee80211_aes_cmac_256(struct crypto_shash *tfm, const u8 *aad,

  			    const u8 *data, size_t data_len, u8 *mic)
  {

  	SHASH_DESC_ON_STACK(desc, tfm);

  	desc->tfm = tfm;

  	crypto_shash_init(desc);
  	crypto_shash_update(desc, aad, AAD_LEN);
  	crypto_shash_update(desc, data, data_len - CMAC_TLEN_256);
  	crypto_shash_finup(desc, zero, CMAC_TLEN_256, mic);

  }

  struct crypto_shash *ieee80211_aes_cmac_key_setup(const u8 key[],
  						  size_t key_len)

  {

  	struct crypto_shash *tfm;

  	tfm = crypto_alloc_shash("cmac(aes)", 0, 0);

  	if (!IS_ERR(tfm))

  		crypto_shash_setkey(tfm, key, key_len);

  
  	return tfm;
  }

  void ieee80211_aes_cmac_key_free(struct crypto_shash *tfm)

  {

  	crypto_free_shash(tfm);

  }