密码工程-大素数

代码：

#include <gmp.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

// Generate a random large prime number between lower and upper bounds
void GenerateLargePrime(mpz_t p, mpz_t l, mpz_t u) {
mpz_t temp;
mpz_init(temp);

gmp_randstate_t state;
gmp_randinit_default(state);
gmp_randseed_ui(state, time(NULL));

do {
mpz_urandomm(temp, state, u); // Generate a random number between 0 and u
mpz_add(temp, temp, l); // Add l to the random number to get a number between l and u
mpz_nextprime(p, temp); // Find the next prime number after temp
} while (mpz_cmp(p, u) > 0); // Repeat until the prime number is within the range [l, u]

mpz_clear(temp);
gmp_randclear(state);
}

int main() {
mpz_t l, u, p;
mpz_init(l);
mpz_init(u);
mpz_init(p);

mpz_set_str(l, "57896044618658097711785492504343953926634992332820282019728792003956564819968", 10); // Set lower bound 2^255
mpz_set_str(u, "115792089237316195423570985008687907853269984665640564039457584007913129639935", 10); // Set upper bound 2^256-1

GenerateLargePrime(p, l, u);

gmp_printf("Large prime: %Zd\n", p);

mpz_clear(l);
mpz_clear(u);
mpz_clear(p);

return 0;
}