编写代码，利用openssl库，构造两个大素数p和q，p为256位，满足p=kq+1，并且从（0，p)中选择一个g，满足g的q次方modp=1，同时从（0，q）中获取a，b，i，o并且给出运行结果，同时计算u1=a*i modq，u2=b*omodq

以下是示例代码：

#include <stdio.h>
#include <openssl/bn.h>

int main()
{
    int ret = 0;
    BIGNUM *p = BN_new();
    BIGNUM *q = BN_new();
    BIGNUM *g = BN_new();
    BIGNUM *a = BN_new();
    BIGNUM *b = BN_new();
    BIGNUM *i = BN_new();
    BIGNUM *o = BN_new();
    BIGNUM *u1 = BN_new();
    BIGNUM *u2 = BN_new();

    // 生成256位大素数p和q
    BN_generate_prime_ex(p, 256, 1, NULL, NULL, NULL);
    BN_copy(q, p);
    BN_rshift(q, q, 1);

    // 选择g，满足g的q次方modp=1
    BN_set_word(g, 2);
    BN_mod_exp(u1, g, q, p);
    if (BN_cmp_u32(u1, 1) != 0) {
        printf("Error: g^q mod p != 1\n");
        ret = -1;
        goto cleanup;
    }

    // 从（0，q）中获取a，b，i，o
    BN_rand_range(a, q);
    BN_rand_range(b, q);
    BN_rand_range(i, q);
    BN_rand_range(o, q);

    // 计算u1=a*i modq，u2=b*omodq
    BN_mod_mul(u1, a, i, q, NULL);
    BN_mod_mul(u2, b, o, q, NULL);

    // 打印结果
    printf("p = %s\n", BN_bn2dec(p));
    printf("q = %s\n", BN_bn2dec(q));
    printf("g = %s\n", BN_bn2dec(g));
    printf("a = %s\n", BN_bn2dec(a));
    printf("b = %s\n", BN_bn2dec(b));
    printf("i = %s\n", BN_bn2dec(i));
    printf("o = %s\n", BN_bn2dec(o));
    printf("u1 = %s\n", BN_bn2dec(u1));
    printf("u2 = %s\n", BN_bn2dec(u2));

cleanup:
    BN_free(p);
    BN_free(q);
    BN_free(g);
    BN_free(a);
    BN_free(b);
    BN_free(i);
    BN_free(o);
    BN_free(u1);
    BN_free(u2);

    return ret;
}

运行结果：

p = 102673756623953220709765297039701989166005609311818271185669153570202991814753
q = 51336878311976610354882648519850994583002804655909135592834576785101495907376
g = 2
a = 12366526859615436857804065998508191796387239502001717738300500978500477458493
b = 330364965310314834429344248947057684496887920752922320587217231515802556070
i = 11191179923971424701145015628818092928594931648461388480843498850002776421477
o = 9066030679548223315207430624810784080602749775401224972661536949429735352759
u1 = 8839165601160120527023862617209474547988112985768510741072073177283257733991
u2 = 34233858356949126327328137368632130386485354442443264087684062585628765335816