nes-proj/drivers/cpu/cc2538/dev/ctr.c

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/*
* Copyright (c) 2015, Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \addtogroup cc2538-ctr
* @{
*
* \file
* Implementation of the cc2538 AES-CTR driver
*/
#include "contiki.h"
#include "dev/rom-util.h"
#include "dev/ctr.h"
#include <stdbool.h>
#include <stdint.h>
/*---------------------------------------------------------------------------*/
uint8_t
ctr_crypt_start(uint8_t encrypt, uint8_t key_area, const void *nonce,
const void *ictr, uint8_t ctr_len, const void *mdata_in,
void *mdata_out, uint16_t mdata_len, struct process *process)
{
uint32_t ctrl;
uint32_t iv[AES_IV_LEN / sizeof(uint32_t)];
uint8_t nonce_len;
/* Program AES-CTR crypto operation */
ctrl = (((ctr_len >> 2) - 1) << AES_AES_CTRL_CTR_WIDTH_S) | /* CTR width */
AES_AES_CTRL_CTR | /* CTR */
(encrypt ? AES_AES_CTRL_DIRECTION_ENCRYPT : 0); /* En/decryption */
/* Prepare the crypto initialization vector */
nonce_len = AES_IV_LEN - ctr_len;
/* Nonce */
rom_util_memcpy(&((uint8_t *)iv)[0], nonce, nonce_len);
/* Initial counter */
rom_util_memcpy(&((uint8_t *)iv)[nonce_len], ictr, ctr_len);
return aes_auth_crypt_start(ctrl, key_area, iv, NULL, 0,
mdata_in, mdata_out, mdata_len, process);
}
/*---------------------------------------------------------------------------*/
int8_t
ctr_crypt_check_status(void)
{
return aes_auth_crypt_check_status() ? aes_auth_crypt_get_result(NULL, NULL) :
CRYPTO_PENDING;
}
/** @} */