C++ 使用 libssh libary 通过 SSH 检索数据失败

Question

我正在尝试从远程服务器获取命令“df”的输出，稍后我将替换该输出:

#include <libssh/libssh.h>
#include <stdlib.h>
#include <stdio.h>

int main()
{
    ssh_session my_ssh_session;
    int rc;
    ssh_channel channel;
    char buffer[256];
    int nbytes;
    int port = 22;
    my_ssh_session = ssh_new();


    if (my_ssh_session == NULL)
    exit(-1);
    ssh_options_set(my_ssh_session, SSH_OPTIONS_HOST, "192.168.2.2");
    ssh_options_set(my_ssh_session, SSH_OPTIONS_PORT, &port);

    rc = ssh_connect(my_ssh_session);

    if (rc != SSH_OK)
            {
            fprintf(stderr, "Failed %s\n",
            ssh_get_error(my_ssh_session));
            exit(-1);
            }



    channel = ssh_channel_new(my_ssh_session);
    if (channel == NULL)
    return SSH_ERROR;

    rc = ssh_channel_open_session(channel);
    if (rc != SSH_OK)
            {
            ssh_channel_free(channel);
            return rc;
            }
    rc = ssh_channel_request_exec(channel, "df");
    if (rc != SSH_OK)
            {
            ssh_channel_close(channel);
            ssh_channel_free(channel);
            return rc;
            }
    nbytes = ssh_channel_read(channel, buffer, sizeof(buffer), 0);
    while (nbytes > 0)
            {
            if (write(1, buffer, nbytes) != nbytes)
                    {
                    ssh_channel_close(channel);
                    ssh_channel_free(channel);
                    return SSH_ERROR;
                    }
            nbytes = ssh_channel_read(channel, buffer, sizeof(buffer), 0);
            }
    if (nbytes < 0)
            {
            ssh_channel_close(channel);
            ssh_channel_free(channel);
            return SSH_ERROR;
            }
    ssh_channel_send_eof(channel);
    ssh_channel_close(channel);
    ssh_channel_free(channel);
    return SSH_OK;




ssh_disconnect(my_ssh_session);
ssh_free(my_ssh_session);
}

编译器没有显示任何错误， 但我运行程序时没有结果， 我检查了远程服务器的系统日志，发现了以下行:

sshd[12794]:dispatch_protocol_error:类型 90 seq 3

请告知可能是什么问题，

谢谢。

Answer 1

您似乎试图在没有主机验证功能(例如从/.ssh/known_hosts 检查信息)和通过公钥或密码进行用户验证的功能的情况下访问远程服务器。您应该将这两个函数放在

之后

if (rc != SSH_OK)
{
fprintf(stderr, "Failed %s\n", ssh_get_error(my_ssh_session));
exit(-1);
}

浏览 libssh tutorial 中的第 1 章和第 2 章.