C++ SSH会话出现意外状态

将PAM配置为在登录try 失败后等待一段指定时间后才显示新的登录提示后，我想使用一个简单的程序来测试此行为，该程序将try 连接到远程服务器并测量显示登录提示之间的时间间隔:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <libssh/libssh.h>

#define BILLION 1000000000.0

int main(void) {
    struct timespec start, finish;

    ssh_session session;
    int rc;
    int session_status;
    const char *server_banner;
    session = ssh_new();

    const char *host = "10.11.12.13";
    const char *username = "baduser";
    const char *password = "badpass";

    ssh_options_set(session, SSH_OPTIONS_HOST, host);
    ssh_options_set(session, SSH_OPTIONS_USER, username);

    clock_gettime(CLOCK_REALTIME, &start);
    rc = ssh_connect(session);
    session_status = ssh_get_status(session);
    printf("Session status: %d\n", session_status);
    server_banner = ssh_get_serverbanner(session);
    printf("Server banner: %s\n", server_banner);

    if (rc != SSH_OK) {
        fprintf(stderr, "Error connecting to %s: %s\n", host, ssh_get_error(session));
        ssh_free(session);
        exit(-1);
    }

    printf("Return Code is: %d\n", rc);

    if (ssh_userauth_password(session, NULL, password) != SSH_AUTH_ERROR) {
        fprintf(stderr, "Authentication succeeded with incorrect password.\n");
    }
    else {
        fprintf(stderr, "Authentication failed with incorrect password.\n");
    }

    clock_gettime(CLOCK_REALTIME, &finish);

    ssh_disconnect(session);
    ssh_free(session);

    double time_spent = (finish.tv_sec - start.tv_sec) + (finish.tv_nsec - start.tv_nsec) / BILLION;
    printf("Elapsed time: %.4f seconds.\n", time_spent);

    return (0);
}

但是，上面的代码返回以下输出:

Session status: 0
Server banner: SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.8
Return Code is: 0
Authentication succeeded with incorrect password.
Elapsed time: 2.2801 seconds.

令人惊讶的是，会话状态表明连接成功，而且，Authentication succeeded with incorrect password.表示程序能够与服务器连接.这不是真的，因为我从未与服务器交换过密钥.此外，服务器上没有与连接可能使用的任何用户名匹配的用户.

请帮助找出这里发生了什么:如何让程序接收SSH会话的正确状态(连接超时或连接被拒绝，这是从控制台访问服务器时通常会发生的情况).