gf_example_1.c 1.24 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_1.c
*
* Demonstrates using the procedures for examples in GF(2^w) for w <= 32.
*/

#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_1 w - w must be between 1 and 32\n");
exit(1);
}

int main(int argc, char **argv)
{
uint32_t a, b, c;
int w;
gf_t gf;

if (argc != 2) usage(NULL);
w = atoi(argv[1]);
if (w <= 0 || w > 32) usage("Bad w");

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

MOA_Seed(time(0));
a = MOA_Random_W(w, 0);
b = MOA_Random_W(w, 0);

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

gf_init_easy(&gf, w);

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

c = gf.multiply.w32(&gf, a, b);
printf("%u * %u = %u\n", a, b, c);

/* Divide the product by a and b */

printf("%u / %u = %u\n", c, a, gf.divide.w32(&gf, c, a));
printf("%u / %u = %u\n", c, b, gf.divide.w32(&gf, c, b));

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