Subversion Repositories mod_sim_exp

/*

 ============================================================================

 Name        : ModExp.c

 Author      :

 Version     :

 Copyright   : Your copyright notice

 Description : Hello World in C, Ansi-style

 ============================================================================

 */

#include <stdio.h>

#include <stdlib.h>

#include <gmp.h>

int main(void) {

        unsigned int base_width;

        mpz_t x, m, r, R, R2;

        gmp_randstate_t state;

        gmp_randinit_mt(state);

        mpz_init(x);

        mpz_init(m);

        mpz_init(r);

        mpz_init(R);

        mpz_init(R2);

        printf("-- input generator program\n");

        printf("--  generates test values for multiplier testbench\n");

        while (1){

                //read in base_width

                scanf("%d", &base_width);

                if (base_width == 0) break;

                //generate modulus (must be uneven)

                mpz_urandomb(m, state, base_width);

                mpz_setbit(m, 0); //uneven

                //generate x

                mpz_urandomb(x, state, base_width);

                //calculate R

                mpz_set_ui(R, 2);

                mpz_powm_ui(R, R, base_width, m); //R = 2^n mod m

                //calculate R2

                mpz_set_ui(R2, 2);

                mpz_powm(R2, R, R2, m); //R2 = Rē mod m = 2^2n mod m

                //calculate result

                mpz_mul(r, x, R);

                mpz_powm_ui(r, r, 1, m);

                printf("-- x, y, m, result\n");

                gmp_printf("%Zx\n", x);

                gmp_printf("%Zx\n", R2);

                gmp_printf("%Zx\n", m);

                gmp_printf("%Zx\n", r);

        }

        mpz_clear(x);

        mpz_clear(R2);

        mpz_clear(m);

        mpz_clear(r);

        mpz_clear(R);

        gmp_randclear(state);

        return EXIT_SUCCESS;

}