PHP Extension

TCP or TLS over Multiple Hop SSH to Remote Server

See more Socket/SSL/TLS Examples

Demonstrates how to use the Chilkat Socket API to connect to a remote server (using TCP or TLS) tunneled through mulitple-hop SSH. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2 => DestinationServer

The ConnectThroughSsh and UseSsh methods are added in Chilkat version 9.5.0.55 to accomplish this task.

PHP Extension

<?php

include("chilkat.php");

$success = false;

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

$ssh1 = new CkSsh();

// Connect directly to the 1st SSH server.
$success = $ssh1->Connect('serverssh1.com',22);
if ($success != true) {
    print $ssh1->lastErrorText() . "\n";
    exit;
}

// Authenticate using login/password:
$success = $ssh1->AuthenticatePw('ssh1Login','ssh1Password');
if ($success != true) {
    print $ssh1->lastErrorText() . "\n";
    exit;
}

// Connect through the 1st SSH connection to reach a 2nd SSH server.
// Note: Any number of SSH connections may be simultaneously tunneled through a single
// existing SSH connection.
$ssh2 = new CkSsh();
$success = $ssh2->ConnectThroughSsh($ssh1,'serverssh2.com',22);
if ($success != true) {
    print $ssh2->lastErrorText() . "\n";
    exit;
}

// Authenticate with ssh2...
$success = $ssh2->AuthenticatePw('ssh2Login','ssh2Password');
if ($success != true) {
    print $ssh2->lastErrorText() . "\n";
    exit;
}

$socket = new CkSocket();

// Tell the socket object to connect to our destination server though the ssh2 tunnel (which itself is routed through ssh1).
// The connection looks like this:  ApplicationSocket(TLS) => ServerSSH1 => ServerSSH2 => DestinationServer
$success = $socket->UseSsh($ssh2);
if ($success != true) {
    print $socket->lastErrorText() . "\n";
    exit;
}

// Connect using TLS to www.chilkatsoft.com
// We could also tunnel a bare TCP connection by specifying port 80 with useTls = false.
$useTls = true;
$maxWaitMillisec = 20000;
$success = $socket->Connect('www.chilkatsoft.com',443,$useTls,$maxWaitMillisec);
if ($success != true) {
    print $socket->lastErrorText() . "\n";
    exit;
}

// Once the multiple hop SSH tunneled connection is setup,  the socket programming
// is identical to the normal case where we have a direct connection.

// Tell the socket object that all text is to be sent in the utf-8 encoding,
// and the text received is assumed to be utf-8.
$socket->put_StringCharset('utf-8');

// Send an HTTP HEAD request:
$success = $socket->SendString('HEAD / HTTP/1.1\r\nHost: www.chilkatsoft.com\r\n\r\n');
if ($success != true) {
    print $socket->lastErrorText() . "\n";
    exit;
}

// Wait a maximum of 4 seconds while no data is forthcoming:
$socket->put_MaxReadIdleMs(4000);

// Get the 1st response line, which should be "HTTP/1.1 200 OK"
$responseStatusLine = $socket->receiveToCRLF();
if ($socket->get_LastMethodSuccess() != true) {
    print $socket->lastErrorText() . "\n";
    exit;
}

print 'StatusLine: ' . $responseStatusLine . "\n";

// Now get the 1st line of the response header:
$responseHeaderLine = $socket->receiveToCRLF();
if ($socket->get_LastMethodSuccess() != true) {
    print $socket->lastErrorText() . "\n";
    exit;
}

print 'HeaderLine: ' . $responseHeaderLine . "\n";

// Now read the remainder of the response header by reading until a double CRLF is seen:
$remainderOfHeader = $socket->receiveUntilMatch('\r\n\r\n');
if ($socket->get_LastMethodSuccess() != true) {
    print $socket->lastErrorText() . "\n";
    exit;
}

print 'Remainder: ' . $remainderOfHeader . "\n";

// Close the connection with the server.  This closes the tunnel through ssh2.
// Wait a max of 20 seconds (20000 millsec)
$success = $socket->Close(20000);

// Close the connection with ssh2.  (This closes the the tunnel through ssh1.)
// The connection with ssh1 is still alive, and may be used for more connections.
$ssh2->Disconnect();

$ssh1->Disconnect();

?>