michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "mpi.h"
michael@0: #include "mplogic.h"
michael@0: #include "ecl.h"
michael@0: #include "ecp.h"
michael@0: #include "ecl-priv.h"
michael@0: 
michael@0: #include <sys/types.h>
michael@0: #include <stdio.h>
michael@0: #include <time.h>
michael@0: #include <sys/time.h>
michael@0: #include <sys/resource.h>
michael@0: 
michael@0: /* Returns 2^e as an integer. This is meant to be used for small powers of 
michael@0:  * two. */
michael@0: int ec_twoTo(int e);
michael@0: 
michael@0: /* Number of bits of scalar to test */
michael@0: #define BITSIZE 160
michael@0: 
michael@0: /* Time k repetitions of operation op. */
michael@0: #define M_TimeOperation(op, k) { \
michael@0: 	double dStart, dNow, dUserTime; \
michael@0: 	struct rusage ru; \
michael@0: 	int i; \
michael@0: 	getrusage(RUSAGE_SELF, &ru); \
michael@0: 	dStart = (double)ru.ru_utime.tv_sec+(double)ru.ru_utime.tv_usec*0.000001; \
michael@0: 	for (i = 0; i < k; i++) { \
michael@0: 		{ op; } \
michael@0: 	}; \
michael@0: 	getrusage(RUSAGE_SELF, &ru); \
michael@0: 	dNow = (double)ru.ru_utime.tv_sec+(double)ru.ru_utime.tv_usec*0.000001; \
michael@0: 	dUserTime = dNow-dStart; \
michael@0: 	if (dUserTime) printf("    %-45s\n      k: %6i, t: %6.2f sec\n", #op, k, dUserTime); \
michael@0: }
michael@0: 
michael@0: /* Tests wNAF computation. Non-adjacent-form is discussed in the paper: D. 
michael@0:  * Hankerson, J. Hernandez and A. Menezes, "Software implementation of
michael@0:  * elliptic curve cryptography over binary fields", Proc. CHES 2000. */
michael@0: 
michael@0: mp_err
michael@0: main(void)
michael@0: {
michael@0: 	signed char naf[BITSIZE + 1];
michael@0: 	ECGroup *group = NULL;
michael@0: 	mp_int k;
michael@0: 	mp_int *scalar;
michael@0: 	int i, count;
michael@0: 	int res;
michael@0: 	int w = 5;
michael@0: 	char s[1000];
michael@0: 
michael@0: 	/* Get a 160 bit scalar to compute wNAF from */
michael@0: 	group = ECGroup_fromName(ECCurve_SECG_PRIME_160R1);
michael@0: 	scalar = &group->genx;
michael@0: 
michael@0: 	/* Compute wNAF representation of scalar */
michael@0: 	ec_compute_wNAF(naf, BITSIZE, scalar, w);
michael@0: 
michael@0: 	/* Verify correctness of representation */
michael@0: 	mp_init(&k);				/* init k to 0 */
michael@0: 
michael@0: 	for (i = BITSIZE; i >= 0; i--) {
michael@0: 		mp_add(&k, &k, &k);
michael@0: 		/* digits in mp_???_d are unsigned */
michael@0: 		if (naf[i] >= 0) {
michael@0: 			mp_add_d(&k, naf[i], &k);
michael@0: 		} else {
michael@0: 			mp_sub_d(&k, -naf[i], &k);
michael@0: 		}
michael@0: 	}
michael@0: 
michael@0: 	if (mp_cmp(&k, scalar) != 0) {
michael@0: 		printf("Error:  incorrect NAF value.\n");
michael@0: 		MP_CHECKOK(mp_toradix(&k, s, 16));
michael@0: 		printf("NAF value   %s\n", s);
michael@0: 		MP_CHECKOK(mp_toradix(scalar, s, 16));
michael@0: 		printf("original value   %s\n", s);
michael@0: 		goto CLEANUP;
michael@0: 	}
michael@0: 
michael@0: 	/* Verify digits of representation are valid */
michael@0: 	for (i = 0; i <= BITSIZE; i++) {
michael@0: 		if (naf[i] % 2 == 0 && naf[i] != 0) {
michael@0: 			printf("Error:  Even non-zero digit found.\n");
michael@0: 			goto CLEANUP;
michael@0: 		}
michael@0: 		if (naf[i] < -(ec_twoTo(w - 1)) || naf[i] >= ec_twoTo(w - 1)) {
michael@0: 			printf("Error:  Magnitude of naf digit too large.\n");
michael@0: 			goto CLEANUP;
michael@0: 		}
michael@0: 	}
michael@0: 
michael@0: 	/* Verify sparsity of representation */
michael@0: 	count = w - 1;
michael@0: 	for (i = 0; i <= BITSIZE; i++) {
michael@0: 		if (naf[i] != 0) {
michael@0: 			if (count < w - 1) {
michael@0: 				printf("Error:  Sparsity failed.\n");
michael@0: 				goto CLEANUP;
michael@0: 			}
michael@0: 			count = 0;
michael@0: 		} else
michael@0: 			count++;
michael@0: 	}
michael@0: 
michael@0: 	/* Check timing */
michael@0: 	M_TimeOperation(ec_compute_wNAF(naf, BITSIZE, scalar, w), 10000);
michael@0: 
michael@0: 	printf("Test passed.\n");
michael@0:   CLEANUP:
michael@0: 	ECGroup_free(group);
michael@0: 	return MP_OKAY;
michael@0: }