gf_example_3.c 1.86 KB
``````/*
* GF-Complete: A Comprehensive Open Source Library for Galois Field Arithmetic
* James S. Plank, Ethan L. Miller, Kevin M. Greenan,
* Benjamin A. Arnold, John A. Burnum, Adam W. Disney, Allen C. McBride.
*
* gf_example_3.c
*
* Identical to example_2 except it works in GF(2^64)
*/

#include <stdio.h>
#include <getopt.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>

#include "gf_complete.h"
#include "gf_rand.h"

void usage(char *s)
{
fprintf(stderr, "usage: gf_example_3\n");
exit(1);
}

int main(int argc, char **argv)
{
uint64_t a, b, c;
uint64_t *r1, *r2;
int i;
gf_t gf;

if (argc != 1) usage(NULL);

/* Get two random numbers in a and b */

MOA_Seed(time(0));
a = MOA_Random_64();
b = MOA_Random_64();

/* Create the proper instance of the gf_t object using defaults: */

gf_init_easy(&gf, 64);

/* And multiply a and b using the galois field: */

c = gf.multiply.w64(&gf, a, b);
printf("%llx * %llx = %llx\n", (long long unsigned int) a, (long long unsigned int) b, (long long unsigned int) c);

/* Divide the product by a and b */

printf("%llx / %llx = %llx\n", (long long unsigned int) c, (long long unsigned int) a, (long long unsigned int) gf.divide.w64(&gf, c, a));
printf("%llx / %llx = %llx\n", (long long unsigned int) c, (long long unsigned int) b, (long long unsigned int) gf.divide.w64(&gf, c, b));

r1 = (uint64_t *) malloc(32);
r2 = (uint64_t *) malloc(32);

r1[0] = b;

for (i = 1; i < 4; i++) r1[i] = MOA_Random_64();

gf.multiply_region.w64(&gf, r1, r2, a, 32, 0);

printf("\nmultiply_region by %llx\n\n", (long long unsigned int) a);
printf("R1 (the source):  ");
for (i = 0; i < 4; i++) printf(" %016llx", (long long unsigned int) r1[i]);

printf("\nR2 (the product): ");
for (i = 0; i < 4; i++) printf(" %016llx", (long long unsigned int) r2[i]);
printf("\n");

exit(0);
}
``````