osd-contiki/cpu/cc2538/dev/ecc-algorithm.c
2016-10-26 00:04:58 +02:00

202 lines
8.1 KiB
C

/*
* Copyright (c) 2014, Institute for Pervasive Computing, ETH Zurich.
* All rights reserved.
*
* Author: Andreas Dröscher <contiki@anticat.ch>
*
* 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.
*/
/**
* \addtogroup cc2538-ecc-algo
* @{
*
* \file
* Implementation of the cc2538 ECC Algorithms
*/
#include "contiki.h"
#include "sys/process.h"
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include "dev/ecc-algorithm.h"
#include "dev/ecc-driver.h"
#include "dev/pka.h"
#define CHECK_RESULT(...) \
state->result = __VA_ARGS__; \
if(state->result) { \
printf("Line: %u Error: %u\n", __LINE__, (unsigned int)state->result); \
PT_EXIT(&state->pt); \
}
PT_THREAD(ecc_compare(ecc_compare_state_t *state)) {
PT_BEGIN(&state->pt);
CHECK_RESULT(bignum_cmp_start(state->a, state->b, state->size, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
state->result = bignum_cmp_get_result();
PT_END(&state->pt);
}
PT_THREAD(ecc_multiply(ecc_multiply_state_t *state)) {
PT_BEGIN(&state->pt);
CHECK_RESULT(ecc_mul_start(state->secret, &state->point_in, state->curve_info, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
CHECK_RESULT(ecc_mul_get_result(&state->point_out, state->rv));
PT_END(&state->pt);
}
PT_THREAD(ecc_dsa_sign(ecc_dsa_sign_state_t *state)) {
/* Executed Every Time */
uint8_t size = state->curve_info->size;
const uint32_t *ord = state->curve_info->n;
ec_point_t point;
memcpy(point.x, state->curve_info->x, sizeof(point.x));
memcpy(point.y, state->curve_info->y, sizeof(point.y));
PT_BEGIN(&state->pt);
/* Invert k_e mod n */
CHECK_RESULT(bignum_inv_mod_start(state->k_e, size, ord, size, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
CHECK_RESULT(bignum_inv_mod_get_result(state->k_e_inv, size, state->rv));
/* Calculate Point R = K_e * GeneratorPoint */
CHECK_RESULT(ecc_mul_start(state->k_e, &point, state->curve_info, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
CHECK_RESULT(ecc_mul_get_result(&state->point_r, state->rv));
/* Calculate signature using big math functions
* d*r (r is the x coordinate of PointR) */
CHECK_RESULT(bignum_mul_start(state->secret, size, state->point_r.x, size, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
state->len = 24;
CHECK_RESULT(bignum_mul_get_result(state->signature_s, &state->len, state->rv));
/* d*r mod n */
CHECK_RESULT(bignum_mod_start(state->signature_s, state->len, ord, size, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
CHECK_RESULT(bignum_mod_get_result(state->signature_s, size, state->rv));
/* hash + d*r */
CHECK_RESULT(bignum_add_start(state->hash, size, state->signature_s, size, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
state->len = 24;
CHECK_RESULT(bignum_add_get_result(state->signature_s, &state->len, state->rv));
/* hash + d*r mod n */
CHECK_RESULT(bignum_mod_start(state->signature_s, state->len, ord, size, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
CHECK_RESULT(bignum_mod_get_result(state->signature_s, size, state->rv));
/* k_e_inv * (hash + d*r) */
CHECK_RESULT(bignum_mul_start(state->k_e_inv, size, state->signature_s, size, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
state->len = 24;
CHECK_RESULT(bignum_mul_get_result(state->signature_s, &state->len, state->rv));
/* k_e_inv * (hash + d*r) mod n */
CHECK_RESULT(bignum_mod_start(state->signature_s, state->len, ord, size, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
CHECK_RESULT(bignum_mod_get_result(state->signature_s, size, state->rv));
PT_END(&state->pt);
}
PT_THREAD(ecc_dsa_verify(ecc_dsa_verify_state_t *state)) {
/* Executed Every Time */
uint8_t size = state->curve_info->size;
const uint32_t *ord = state->curve_info->n;
ec_point_t point;
memcpy(point.x, state->curve_info->x, sizeof(point.x));
memcpy(point.y, state->curve_info->y, sizeof(point.y));
PT_BEGIN(&state->pt);
/* Invert s mod n */
CHECK_RESULT(bignum_inv_mod_start(state->signature_s, size, ord, size, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
CHECK_RESULT(bignum_inv_mod_get_result(state->s_inv, size, state->rv));
/* Calculate u1 = s_inv * hash */
CHECK_RESULT(bignum_mul_start(state->s_inv, size, state->hash, size, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
state->len = 24;
CHECK_RESULT(bignum_mul_get_result(state->u1, &state->len, state->rv));
/* Calculate u1 = s_inv * hash mod n */
CHECK_RESULT(bignum_mod_start(state->u1, state->len, ord, size, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
CHECK_RESULT(bignum_mod_get_result(state->u1, size, state->rv));
/* Calculate u2 = s_inv * r */
CHECK_RESULT(bignum_mul_start(state->s_inv, size, state->signature_r, size, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
state->len = 24;
CHECK_RESULT(bignum_mul_get_result(state->u2, &state->len, state->rv));
/* Calculate u2 = s_inv * r mod n */
CHECK_RESULT(bignum_mod_start(state->u2, state->len, ord, size, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
CHECK_RESULT(bignum_mod_get_result(state->u2, size, state->rv));
/* Calculate p1 = u1 * A */
CHECK_RESULT(ecc_mul_start(state->u1, &point, state->curve_info, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
CHECK_RESULT(ecc_mul_get_result(&state->p1, state->rv));
/* Calculate p2 = u1 * B */
CHECK_RESULT(ecc_mul_start(state->u2, &state->public, state->curve_info, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
CHECK_RESULT(ecc_mul_get_result(&state->p2, state->rv));
/* Calculate P = p1 + p2 */
CHECK_RESULT(ecc_add_start(&state->p1, &state->p2, state->curve_info, &state->rv, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
CHECK_RESULT(ecc_add_get_result(&state->p1, state->rv));
/* Verify Result */
CHECK_RESULT(bignum_cmp_start(state->signature_r, state->p1.x, size, state->process));
PT_WAIT_UNTIL(&state->pt, pka_check_status());
state->result = bignum_cmp_get_result();
if((state->result == PKA_STATUS_A_GR_B) || (state->result == PKA_STATUS_A_LT_B)) {
state->result = PKA_STATUS_SIGNATURE_INVALID;
}
PT_END(&state->pt);
}
/**
* @}
* @}
*/