使用c语言和openssl编写rsa算法

下面是一个使用C语言和OpenSSL库编写RSA算法的示例代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/rsa.h>
#include <openssl/pem.h>

int main(void)
{
    RSA *rsa = NULL;
    BIO *bio = NULL;
    char *pubkey = "-----BEGIN PUBLIC KEY-----\n\
                    MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEA3SHxX3Qv3RrXn7WUuqE2\n\
                    6fL6Nz7mTfjTgJZv5j4Jl9QyJZzJF9eQ3oLJHJG3cBfXWw1XH+df/g8pB3xhVJb7\n\
                    4xTmTnGpQ5FezX8Wjh7ACs1xuMfDLG7/JJWvI1D4Y5mB9GZc82XbYJZ2vYBDCs0i\n\
                    fK8rlnP1n7k1Y0myY9tQ3rKv7lW9HJkLw3O7Xo0lJL1+3dCjJf8z7QaQ8SjvD7XZ\n\
                    8ia5S2TJLmNi2bGKmRzGZnKJmQOqoe9sJZlUyOJyv/8fLmJQvZc9OJ5yv5BHJm3D\n\
                    bXAyNzdZ9QF4JW6ZzvRn9t+JQ1uXw8yCQ7KEv8kX8hxXg3Zj8o1sP3Vn7ZiEIN6V\n\
                    n2U5zvLZ0rN7tXrW1U3j4C8e3YJ0Df2KXyRqZDrm0ZlZz4L3h3JF7qWx3eQwVMtU\n\
                    fWV1PvoqJ2OQzILU1FJ3oVJ5d5PpRhXeKlD4Z0JvL8F2DY7Kjy+4mL3g1jX9W1JJ\n\
                    2+8eW4w8z6Y+3WpL3n8kBuRRkS5hRv1Cw6dRQ9Q4dM7xKlJjU7W9C5H4K6c+YwCJ\n\
                    9YApdJqR1Pz3YfJ2c5bM67Jc0n9zGdH5JZyyqoI6bKzqjpfC3ZcR5I7Q9pFJmzWu\n\
                    k5A0yy/4yxPnDw5txrNZtL1DemyKv4XUrC9VZl98y3KZyYK+7UgZb3Z6QZQu3IjL\n\
                    3xj2tJz6GtDfX7J7H+2c4jECAwEAAQ==\n\
                    -----END PUBLIC KEY-----";

    char *privkey = "-----BEGIN PRIVATE KEY-----\n\
                    MIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQDdIfFfdC/dGted\n\
                    +1lLqhNuny+jc+5k3484CZb+Y+CZfUMiWcyRfXkN6CyRyRt3AX11sNVx/nX/4PKQ\n\
                    f8YVSW++MU5k5xqUORXs1/Fo4ewArNcbjHwyxu/ySVryNQ+GOZgfRmXPNl22CWdr\n\
                    9gEMKzSJ8ryuWc/WfuTVjSbJj21Desq/uVb0cmQvDc7tejSUkvX7d0KMl/zPtBpD\n\
                    xKO8PtdnyJrlLZMkuaNjZsYqZHMZmcomZA6qh72wlmVTI4nK//x8uYlC9lz04nnK\n\
                    /kEcmbcNtcDI3N1n1AXglbpnO9Gf234lDW5fDzIJDsoS/yRfyHFeDdmPyjWw/dWf\n\
                    tmIQg3pWfZTnO8tnSs3u1etbVTePgLx7dgnQN/YpfJGpkOubRmVnPgve