#include?“l(fā)ibssh2_config.h“
#include?

#ifdef?WIN32
#include?
#include?
#include?
#else
#include?
#include?
#include?
#include?
#endif

#include?
#include?
#include?
#include?
#include?
#include?

#ifdef?HAVE_SYS_SELECT_H
#include?
#endif

#ifndef?INADDR_NONE
#define?INADDR_NONE?（in_addr_t）-1
#endif

const?char?*keyfile1?=?“/home/username/.ssh/id_rsa.pub“;
const?char?*keyfile2?=?“/home/username/.ssh/id_rsa“;
const?char?*username?=?“username“;
const?char?*password?=?““;

const?char?*server_ip?=?“127.0.0.1“;

const?char?*local_listenip?=?“127.0.0.1“;
unsigned?int?local_listenport?=?2222;

const?char?*remote_desthost?=?“l(fā)ocalhost“;?/*?resolved?by?the?server?*/
unsigned?int?remote_destport?=?22;

enum?{
????AUTH_NONE?=?0
????AUTH_PASSWORD
????AUTH_PUBLICKEY
};

int?main（int?argc?char?*argv[]）
{
????int?rc?sock?=?-1?listensock?=?-1?forwardsock?=?-1?i?auth?=?AUTH_NONE;
????struct?sockaddr_in?sin;
????socklen_t?sinlen;
????const?char?*fingerprint;
????char?*userauthlist;
????LIBSSH2_SESSION?*session;
????LIBSSH2_CHANNEL?*channel?=?NULL;
????const?char?*shost;
????unsigned?int?sport;
????fd_set?fds;
????struct?timeval?tv;
????ssize_t?len?wr;
????char?buf[16384];

#ifdef?WIN32
????char?sockopt;
????WSADATA?wsadata;

????WSAStartup（MAKEWORD（20）?&wsadata）;
#else
????int?sockopt;
#endif

????if?（argc?>?1）
????????server_ip?=?argv[1];
????if?（argc?>?2）
????????username?=?argv[2];
????if?（argc?>?3）
????????password?=?argv[3];
????if?（argc?>?4）
????????local_listenip?=?argv[4];
????if?（argc?>?5）
????????local_listenport?=?atoi（argv[5]）;
????if?（argc?>?6）
????????remote_desthost?=?argv[6];
????if?（argc?>?7）
????????remote_destport?=?atoi（argv[7]）;

????rc?=?libssh2_init?（0）;
????if?（rc?!=?0）?{
????????fprintf?（stderr?“l(fā)ibssh2?initialization?failed?（%d）\n“?rc）;
????????return?1;
????}

????/*?Connect?to?SSH?server?*/
????sock?=?socket（PF_INET?SOCK_STREAM?IPPROTO_TCP）;
????sin.sin_family?=?AF_INET;
????if?（INADDR_NONE?==?（sin.sin_addr.s_addr?=?inet_addr（server_ip）））?{
????????perror（“inet_addr“）;
????????return?-1;
????}
????sin.sin_port?=?htons（22）;
????if?（connect（sock?（struct?sockaddr*）（&sin）
????????????????sizeof（struct?sockaddr_in））?!=?0）?{
????????fprintf（stderr?“failed?to?connect!\n“）;
????????return?-1;
????}

????/*?Create?a?session?instance?*/
????session?=?libssh2_session_init（）;
????if（!session）?{
????????fprintf（stderr?“Could?not?initialize?SSH?session!\n“）;
????????return?-1;
????}

????/*?...?start?it?up.?This?will?trade?welcome?banners?exchange?keys
?????*?and?setup?crypto?compression?and?MAC?layers
?????*/
????rc?=?libssh2_session_handshake（session?sock）;
????if（rc）?{
????????fprintf（stderr?“Error?when?starting?up?SSH?session:?%d\n“?rc）;
????????return?-1;
????}

????/*?At?this?point?we?havn‘t?yet?authenticated.??The?first?thing?to?do
?????*?is?check?