(PHP Extension) SSH Tunnel Inside another SSH Tunnel

Demonstrates how to create a TCP/IP socket connection through an SSH tunnel that is dynamic port forwarded through another SSH tunnel.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// This example requires Chilkat version 9.5.0.50 or greater.
$tunnel = new CkSshTunnel();

$sshHostname = 'www.ssh-serverA.com';
$sshPort = 22;

// Connect to an SSH server and establish the SSH tunnel:
$success = $tunnel->Connect($sshHostname,$sshPort);
if ($success != true) {
    print $tunnel->lastErrorText() . "\n";
    exit;
}

// Authenticate with the SSH server via a login/password
// or with a public key.  
// This example demonstrates SSH password authentication.
$success = $tunnel->AuthenticatePw('mySshLogin','mySshPassword');
if ($success != true) {
    print $tunnel->lastErrorText() . "\n";
    exit;
}

// Indicate that the background SSH tunnel thread will behave as a SOCKS proxy server
// with dynamic port forwarding:
$tunnel->put_DynamicPortForwarding(true);

// We may optionally require that connecting clients authenticate with our SOCKS proxy server.
// To do this, set an inbound username/password.  Any connecting clients would be required to 
// use SOCKS5 with the correct username/password.
// If no inbound username/password is set, then our SOCKS proxy server will accept both
// SOCKS4 and SOCKS5 unauthenticated connections.

$tunnel->put_InboundSocksUsername('chilkat123');
$tunnel->put_InboundSocksPassword('password123');

// Start the listen/accept thread to begin accepting SOCKS proxy client connections.
// Listen on port 1080.
$success = $tunnel->BeginAccepting(1080);
if ($success != true) {
    print $tunnel->lastErrorText() . "\n";
    exit;
}

// Now that a background thread is running a SOCKS proxy server that forwards connections
// through an SSH tunnel, it is possible to use any Chilkat implemented protocol that is SOCKS capable,
// such as HTTP, POP3, SMTP, IMAP, FTP, Socket, etc.  The protocol may use SSL/TLS because the SSL/TLS
// will be passed through the SSH tunnel to the end-destination.  Also, any number of simultaneous
// connections may be routed through the SSH tunnel.

$tunnelB = new CkSocket();

// Indicate that the socket object is to use our portable SOCKS proxy/SSH tunnel running in our background thread.
$tunnelB->put_SocksHostname('localhost');
$tunnelB->put_SocksPort(1080);
$tunnelB->put_SocksVersion(5);
$tunnelB->put_SocksUsername('chilkat123');
$tunnelB->put_SocksPassword('password123');

// Open a new SSH tunnel through the existing tunnel (via what we treat as a SOCKS5 proxy,
// but it is actually a dynamic port-forwarded SSH tunnel).
$success = $tunnelB->SshOpenTunnel('www.ssh-serverB.com',22);
if ($success != true) {
    print $tunnelB->lastErrorText() . "\n";
    exit;
}

// Authenticate with ssh-serverB.com
$success = $tunnelB->SshAuthenticatePw('uname','pwd');
if ($success != true) {
    print $tunnelB->lastErrorText() . "\n";
    exit;
}

// OK, the SSH tunnel (within a tunnel) is setup.  Now open a channel within the tunnel.
// Once the channel is obtained, the Socket API may
// be used exactly the same as usual, except all communications
// are sent through the channel in the SSH tunnel.
// Any number of channels may be created from the same SSH tunnel.
// Multiple channels may coexist at the same time.

// Connect to an NIST time server and read the current date/time

$maxWaitMs = 4000;
$useTls = false;
// channel is a CkSocket
$channel = $tunnelB->SshOpenChannel('time-c.nist.gov',37,$useTls,$maxWaitMs);
if ($tunnelB->get_LastMethodSuccess() == false) {
    print $tunnelB->lastErrorText() . "\n";
    exit;
}

// The time server will send a big-endian 32-bit integer representing
// the number of seconds since since 00:00 (midnight) 1 January 1900 GMT.
// The ReceiveInt32 method will receive a 4-byte integer, but returns
// true or false to indicate success.  If successful, the integer
// is obtained via the ReceivedInt property.
$bigEndian = true;
$success = $channel->ReceiveInt32($bigEndian);
if ($success != true) {
    print $channel->lastErrorText() . "\n";

    exit;
}

$dt = new CkDateTime();
$dt->SetFromNtpTime($channel->get_ReceivedInt());

// Show the current local date/time
$bLocalTime = true;
print 'Current local date/time: ' . $dt->getAsRfc822($bLocalTime) . "\n";

// Close the SSH channel.
$success = $channel->Close($maxWaitMs);
if ($success != true) {
    print $channel->lastErrorText() . "\n";

    exit;
}

// Stop the background listen/accept thread:
$waitForThreadExit = true;
$success = $tunnel->StopAccepting($waitForThreadExit);
if ($success != true) {
    print $tunnel->lastErrorText() . "\n";
    exit;
}

// Close the SSH tunnel (would also kick any remaining connected clients).
$success = $tunnel->CloseTunnel($waitForThreadExit);
if ($success != true) {
    print $tunnel->lastErrorText() . "\n";
    exit;
}


?>