gf_example_4.c 1.61 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_4.c
*
* Identical to example_3 except it works in GF(2^128)
*/

#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"

#define LLUI (long long unsigned int)

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

int main(int argc, char **argv)
{
uint64_t a[2], b[2], c[2];
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));
MOA_Random_128(a);
MOA_Random_128(b);

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

gf_init_easy(&gf, 128);

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

gf.multiply.w128(&gf, a, b, c);
printf("%016llx%016llx * %016llx%016llx =\n%016llx%016llx\n",
LLUI a[0], LLUI a[1], LLUI b[0], LLUI b[1], LLUI c[0], LLUI c[1]);

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

for (i = 0; i < 4; i++) r1[i] = MOA_Random_64();

gf.multiply_region.w128(&gf, r1, r2, a, 32, 0);

printf("\nmultiply_region by %016llx%016llx\n\n", LLUI a[0], LLUI a[1]);
printf("R1 (the source):  ");
for (i = 0; i < 4; i += 2) printf(" %016llx%016llx", LLUI r1[i], LLUI r1[i+1]);

printf("\nR2 (the product): ");
for (i = 0; i < 4; i += 2) printf(" %016llx%016llx", LLUI r2[i], LLUI r2[i+1]);
printf("\n");
exit(0);
}
``````