输出一个C语言编程的RSA算法

RSA算法是一种非对称加密算法，它的原理是利用两个大质数的乘积作为公钥，而这两个质数的乘积作为私钥，通过这种方式实现加密和解密。以下是一个C语言编程的RSA算法示例：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <math.h>

#define MAX_PRIME 100000

int is_prime(int n) {
    if (n <= 1) {
        return ;
    }
    for (int i = 2; i <= sqrt(n); i++) {
        if (n % i == ) {
            return ;
        }
    }
    return 1;
}

int gcd(int a, int b) {
    if (b == ) {
        return a;
    }
    return gcd(b, a % b);
}

int mod_pow(int base, int exponent, int modulus) {
    int result = 1;
    while (exponent > ) {
        if (exponent % 2 == 1) {
            result = (result * base) % modulus;
        }
        base = (base * base) % modulus;
        exponent /= 2;
    }
    return result;
}

int main() {
    srand(time(NULL));
    int p = rand() % MAX_PRIME;
    while (!is_prime(p)) {
        p = rand() % MAX_PRIME;
    }
    int q = rand() % MAX_PRIME;
    while (!is_prime(q) || q == p) {
        q = rand() % MAX_PRIME;
    }
    int n = p * q;
    int phi = (p - 1) * (q - 1);
    int e = rand() % phi;
    while (gcd(e, phi) != 1) {
        e = rand() % phi;
    }
    int d = ;
    int k = 1;
    while (1) {
        d = (k * phi + 1) / e;
        if (e * d == k * phi + 1) {
            break;
        }
        k++;
    }
    printf("p = %d\n", p);
    printf("q = %d\n", q);
    printf("n = %d\n", n);
    printf("phi = %d\n", phi);
    printf("e = %d\n", e);
    printf("d = %d\n", d);
    int plaintext = 12345;
    int ciphertext = mod_pow(plaintext, e, n);
    printf("plaintext = %d\n", plaintext);
    printf("ciphertext = %d\n", ciphertext);
    int decryptedtext = mod_pow(ciphertext, d, n);
    printf("decryptedtext = %d\n", decryptedtext);
    return ;
}

这个程序会随机生成两个质数p和q，然后计算出n和phi，再随机生成一个与phi互质的整数e，最后计算出d，这样就得到了公钥(n, e)和私钥(n, d)。程序还演示了如何使用公钥加密和私钥解密一个整数。