contiki/cpu/cc2538/dev/ccm.c
Benoît Thébaudeau 69eacbddbe cc2538: Add AES-CCM* driver
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau.dev@gmail.com>
2016-01-04 00:28:27 +01:00

143 lines
5.6 KiB
C

/*
* Original file:
* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
* All rights reserved.
*
* Port to Contiki:
* Copyright (c) 2013, ADVANSEE - http://www.advansee.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-ccm
* @{
*
* \file
* Implementation of the cc2538 AES-CCM driver
*/
#include "contiki.h"
#include "sys/cc.h"
#include "dev/rom-util.h"
#include "dev/ccm.h"
#include <stdbool.h>
#include <stdint.h>
/*---------------------------------------------------------------------------*/
static uint8_t
ccm_auth_crypt_start(uint8_t encrypt, uint8_t len_len, uint8_t key_area,
const void *nonce, const void *adata, uint16_t adata_len,
const void *data_in, void *data_out, uint16_t data_len,
uint8_t mic_len, struct process *process)
{
uint32_t ctrl;
uint32_t iv[AES_IV_LEN / sizeof(uint32_t)];
/* Program AES-CCM authentication/crypto operation */
ctrl = AES_AES_CTRL_SAVE_CONTEXT | /* Save context */
(((MAX(mic_len, 2) - 2) >> 1) << AES_AES_CTRL_CCM_M_S) | /* M */
((len_len - 1) << AES_AES_CTRL_CCM_L_S) | /* L */
AES_AES_CTRL_CCM | /* CCM */
AES_AES_CTRL_CTR_WIDTH_128 | /* CTR width 128 */
AES_AES_CTRL_CTR | /* CTR */
(encrypt ? AES_AES_CTRL_DIRECTION_ENCRYPT : 0); /* En/decryption */
/* Prepare the crypto initialization vector
* Flags: L' = L - 1 */
((uint8_t *)iv)[0] = len_len - 1;
/* Nonce */
rom_util_memcpy(&((uint8_t *)iv)[CCM_FLAGS_LEN], nonce,
CCM_NONCE_LEN_LEN - len_len);
/* Initialize counter to 0 */
rom_util_memset(&((uint8_t *)iv)[AES_IV_LEN - len_len], 0, len_len);
return aes_auth_crypt_start(ctrl, key_area, iv, adata, adata_len,
data_in, data_out, data_len, process);
}
/*---------------------------------------------------------------------------*/
static uint8_t
ccm_auth_crypt_get_result(const void *cdata, uint16_t cdata_len,
void *mic, uint8_t mic_len)
{
uint32_t tag[AES_TAG_LEN / sizeof(uint32_t)];
uint16_t data_len;
uint8_t ret;
ret = aes_auth_crypt_get_result(NULL, tag);
if(ret != CRYPTO_SUCCESS) {
return ret;
}
if(cdata != NULL) {
/* Check MIC */
data_len = cdata_len - mic_len;
if(rom_util_memcmp(tag, &((const uint8_t *)cdata)[data_len], mic_len)) {
ret = AES_AUTHENTICATION_FAILED;
}
}
/* Copy tag to MIC */
rom_util_memcpy(mic, tag, mic_len);
return ret;
}
/*---------------------------------------------------------------------------*/
uint8_t
ccm_auth_encrypt_start(uint8_t len_len, uint8_t key_area, const void *nonce,
const void *adata, uint16_t adata_len, const void *pdata,
uint16_t pdata_len, void *cdata, uint8_t mic_len,
struct process *process)
{
return ccm_auth_crypt_start(true, len_len, key_area, nonce, adata, adata_len,
pdata, cdata, pdata_len, mic_len, process);
}
/*---------------------------------------------------------------------------*/
uint8_t
ccm_auth_encrypt_get_result(void *mic, uint8_t mic_len)
{
return ccm_auth_crypt_get_result(NULL, 0, mic, mic_len);
}
/*---------------------------------------------------------------------------*/
uint8_t
ccm_auth_decrypt_start(uint8_t len_len, uint8_t key_area, const void *nonce,
const void *adata, uint16_t adata_len, const void *cdata,
uint16_t cdata_len, void *pdata, uint8_t mic_len,
struct process *process)
{
uint16_t data_len = cdata_len - mic_len;
return ccm_auth_crypt_start(false, len_len, key_area, nonce, adata, adata_len,
cdata, pdata, data_len, mic_len, process);
}
/*---------------------------------------------------------------------------*/
uint8_t
ccm_auth_decrypt_get_result(const void *cdata, uint16_t cdata_len,
void *mic, uint8_t mic_len)
__attribute__ ((alias("ccm_auth_crypt_get_result")));
/** @} */