contiki/cpu/cc2538/dev/gcm.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-gcm
* @{
*
* \file
* Implementation of the cc2538 AES-GCM driver
*/
#include "contiki.h"
#include "dev/rom-util.h"
#include "dev/gcm.h"
#include <stdbool.h>
#include <stdint.h>
/*---------------------------------------------------------------------------*/
static uint8_t
gcm_auth_crypt_start(uint8_t encrypt, uint8_t key_area, const void *iv,
const void *adata, uint16_t adata_len,
const void *data_in, void *data_out, uint16_t data_len,
struct process *process)
{
uint32_t ctrl;
uint32_t aes_iv[AES_IV_LEN / sizeof(uint32_t)];
/* Program AES-GCM authentication/crypto operation */
ctrl = AES_AES_CTRL_SAVE_CONTEXT | /* Save context */
AES_AES_CTRL_GCM | /* GCM */
AES_AES_CTRL_CTR_WIDTH_32 | /* CTR width 32 */
AES_AES_CTRL_CTR | /* CTR */
(encrypt ? AES_AES_CTRL_DIRECTION_ENCRYPT : 0); /* En/decryption */
/* Prepare the crypto initialization vector
* Initialization vector */
rom_util_memcpy(aes_iv, iv, GCM_IV_LEN);
/* Initialize counter to 1 */
aes_iv[GCM_IV_LEN / sizeof(aes_iv[0])] = 0x01000000;
return aes_auth_crypt_start(ctrl, key_area, aes_iv, adata, adata_len,
data_in, data_out, data_len, process);
}
/*---------------------------------------------------------------------------*/
static uint8_t
gcm_auth_crypt_get_result(const void *tag_in, void *tag_out)
{
uint32_t tag[AES_TAG_LEN / sizeof(uint32_t)];
uint8_t ret;
ret = aes_auth_crypt_get_result(NULL, tag);
if(ret != CRYPTO_SUCCESS) {
return ret;
}
if(tag_in != NULL) {
/* Check tag */
if(rom_util_memcmp(tag, tag_in, GCM_TAG_LEN)) {
ret = AES_AUTHENTICATION_FAILED;
}
}
if(tag_out != NULL) {
/* Copy tag */
rom_util_memcpy(tag_out, tag, GCM_TAG_LEN);
}
return ret;
}
/*---------------------------------------------------------------------------*/
uint8_t
gcm_auth_encrypt_start(uint8_t key_area, const void *iv, const void *adata,
uint16_t adata_len, const void *pdata,
uint16_t pdata_len, void *cdata, struct process *process)
{
return gcm_auth_crypt_start(true, key_area, iv, adata, adata_len,
pdata, cdata, pdata_len, process);
}
/*---------------------------------------------------------------------------*/
uint8_t
gcm_auth_encrypt_get_result(void *tag)
{
return gcm_auth_crypt_get_result(NULL, tag);
}
/*---------------------------------------------------------------------------*/
uint8_t
gcm_auth_decrypt_start(uint8_t key_area, const void *iv, const void *adata,
uint16_t adata_len, const void *cdata,
uint16_t cdata_len, void *pdata, struct process *process)
{
return gcm_auth_crypt_start(false, key_area, iv, adata, adata_len,
cdata, pdata, cdata_len, process);
}
/*---------------------------------------------------------------------------*/
uint8_t
gcm_auth_decrypt_get_result(const void *tag_in, void *tag_out)
__attribute__ ((alias("gcm_auth_crypt_get_result")));
/** @} */