Functions for interfacing the built-in AES functions of the CC2420 chip

This commit is contained in:
adamdunkels 2008-07-02 08:46:13 +00:00
parent 3847448496
commit 1da58b8858
2 changed files with 181 additions and 0 deletions

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/*
* Copyright (c) 2008, Swedish Institute of Computer Science.
* 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 Institute 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 INSTITUTE 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 INSTITUTE 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.
*
* This file is part of the Contiki operating system.
*
* $Id: cc2420-aes.c,v 1.1 2008/07/02 08:46:13 adamdunkels Exp $
*/
/**
* \file
* AES encryption/decryption functions.
* \author
* Adam Dunkels <adam@sics.se>
*/
#include "contiki.h"
#include "dev/cc2420-aes.h"
#include "dev/cc2420_const.h"
#include "dev/spi.h"
#define KEYLEN 16
#define MAX_DATALEN 16
#define MIN(a,b) ((a) < (b)? (a): (b))
/*---------------------------------------------------------------------------*/
void
cc2420_aes_set_key(uint8_t *key, int index)
{
uint16_t f;
switch(index) {
case 0:
FASTSPI_WRITE_RAM_LE(key, CC2420RAM_KEY0, KEYLEN, f);
break;
case 1:
FASTSPI_WRITE_RAM_LE(key, CC2420RAM_KEY0, KEYLEN, f);
break;
}
}
/*---------------------------------------------------------------------------*/
/* Encrypt at most 16 bytes of data. */
static void
cipher16(uint8_t *data, int len)
{
uint16_t f;
len = MIN(len, MAX_DATALEN);
FASTSPI_WRITE_RAM_LE(data, CC2420RAM_SABUF, len, f);
FASTSPI_STROBE(CC2420_SAES);
FASTSPI_READ_RAM_LE(data, CC2420RAM_SABUF, len, f);
}
/*---------------------------------------------------------------------------*/
void
cc2420_aes_cihper(uint8_t *data, int len, int key_index)
{
int i;
uint16_t secctrl0;
FASTSPI_GETREG(CC2420_SECCTRL0, secctrl0);
secctrl0 &= ~(CC2420_SECCTRL0_SAKEYSEL0 | CC2420_SECCTRL0_SAKEYSEL1);
switch(key_index) {
case 0:
secctrl0 |= CC2420_SECCTRL0_SAKEYSEL0;
break;
case 1:
secctrl0 |= CC2420_SECCTRL0_SAKEYSEL1;
break;
}
FASTSPI_SETREG(CC2420_SECCTRL0, secctrl0);
for(i = 0; i < len; i = i + MAX_DATALEN) {
cipher16(data + i, MIN(len - i, MAX_DATALEN));
}
}
/*---------------------------------------------------------------------------*/

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/*
* Copyright (c) 2008, Swedish Institute of Computer Science.
* 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 Institute 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 INSTITUTE 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 INSTITUTE 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.
*
* This file is part of the Contiki operating system.
*
* $Id: cc2420-aes.h,v 1.1 2008/07/02 08:46:13 adamdunkels Exp $
*/
/**
* \file
* Interface to the CC2420 AES encryption/decryption functions
* \author
* Adam Dunkels <adam@sics.se>
*/
#ifndef __CC2420_AES_H__
#define __CC2420_AES_H__
/**
* \brief Setup an AES key
* \param key A pointer to a 16-byte AES key
* \param index The key index: either 0 or 1.
*
* This function sets up an AES key with the CC2420
* chip. The AES key can later be used with the
* cc2420_aes_cipher() function to encrypt or decrypt
* data.
*
* The CC2420 can store two separate keys in its
* memory. The keys are indexed as 0 or 1 and the key
* index is given by the 'index' parameter.
*
*/
void cc2420_aes_set_key(uint8_t *key, int index);
/**
* \brief Encrypt/decrypt data with AES
* \param data A pointer to the data to be encrypted/decrypted
* \param len The length of the data to be encrypted/decrypted
* \param key_index The key to use. The key must have previously been set up with cc2420_aes_set_key().
*
* This function encrypts/decrypts data with AES. A
* pointer to the data is passed as a parameter, and the
* function overwrites the data with the encrypted data.
*
*/
void cc2420_aes_cihper(uint8_t *data, int len, int key_index);
#endif /* __CC2420_AES_H__ */