Perl Requires Chilkat v11.0.0+

WebSocket through SSH Tunnel

See more WebSocket Examples

This example shows how to establish a WebSocket connection through an SSH tunnel. The WebSocket protocol communications will be encapsulated within an SSH tunnel. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

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

# --------------------------------------------------
# This example borrows the code from the REST through SSH Tunnel example.
# We first use the Chilkat Socket object to establish a connection to the WebSocket server through an SSH Tunnel.
# Next, the Rest object uses the Socket object for its connection.
# Finally, the WebSocket object uses the Rest object for its connection.
#
# Hopefully the flexibility of this architecture is easy to see.  All of the HTTP functionality of the Rest object,
# such as HTTP authentication, custom headers, etc. is available to the WebSocket.  Likewise, all of the advanced functionality
# of the Socket object is in turn available to the Rest object.

# The high-level steps for accomplishing the task of running the WebSocket protocol through an SSH accomplished as follows:
# 1) Create the SSH tunnel using Chilkat Socket.
# 2) Open a port-forwarding channel (to the WebSocket server) within the tunnel.
# 2) Tell Rest to use the Socket object.
# 3) Tell WebSocket to use the Rest object.

my $tunnel = Chilkat2::Socket->new;

my $sshHostname = 'sftp.example.com';
my $sshPort = 22;

# Connect to an SSH server and establish the SSH tunnel:
my $success = $tunnel->SshOpenTunnel($sshHostname, $sshPort);
if (!$success) {
    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 = $tunnel->SshAuthenticatePw('mySshLogin', 'mySshPassword');
if (!$success) {
    print $tunnel->LastErrorText, "\n";
    exit;
}

#  OK, the SSH tunnel is setup.  Now open a channel within the tunnel.

my $bTls = 1;
my $port = 443;
my $maxWaitMs = 5000;

# This returns a socket object that is a single channel within the SSH tunnel.
# The SSH channel is our logical port-forwarded connection through the SSH tunnel.
# Note: This example establishes a TLS connection to the target WebSocket server.
# (The TLS protocol will run on the logical channel within the SSH tunnel.)
# Your application can just as easily make a non-TLS connection by changing the arguments
# passed to SshNewChannel.
my $channel = Chilkat2::Socket->new;
$success = $tunnel->SshNewChannel('some-websocket-server.com', $port, $bTls, $maxWaitMs, $channel);
if (!$success) {
    print $tunnel->LastErrorText, "\n";
    exit;
}

# Create a REST object and tell it to use the SSH channel.
# This connection is a TLS running on an SSH channel through an SSH tunnel.
# In other words, TLS is wrapped within the SSH tunnel.
my $rest = Chilkat2::Rest->new;
$success = $rest->UseConnection($channel, 0);
if (!$success) {
    print $rest->LastErrorText, "\n";
    exit;
}

# Finally, tell our WebSocket object to use the Rest object..
my $ws = Chilkat2::WebSocket->new;

# Tell the WebSocket to use this connection.
$success = $ws->UseConnection($rest);
if (!$success) {
    print $ws->LastErrorText, "\n";
    exit;
}

# Add the standard WebSocket open handshake headers that will be needed.
# (This adds the required HTTP request headers to the rest object.)
$ws->AddClientHeaders();

# Add any additional headers that might be desired.
# Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
$rest->AddHeader('Sec-WebSocket-Protocol', 'x-some-websocket-subprotocol');
$rest->AddHeader('Origin', 'http://some-websocket-server.com');

# Do the open handshake.
my $responseBody = $rest->FullRequestNoBody('GET', '/something');
if (!$rest->LastMethodSuccess) {
    print $rest->LastErrorText, "\n";
    exit;
}

# If successful, the HTTP response status code should be 101,
# and the response body will be empty. (If it failed, we'll have a look
# at the response body..)
my $statusCode = $rest->ResponseStatusCode;
print 'Response status code: ', $statusCode, "\n";

if ($statusCode != 101) {
    print $responseBody, "\n";
    print "-- Failed because of unexpected response status code.\n";
    exit;
}

# We have the expected 101 response, so let's now validate the
# contents of the response, such as the value sent by the server in the
# Sec-WebSocket-Accept header.
$success = $ws->ValidateServerHandshake();
if (!$success) {
    print $ws->LastErrorText, "\n";
    exit;
}

print "WebSocket connection successful.\n";

# The application may now begin sending and receiving frames on the WebSocket connection.
# (At this point, we're done with the rest object...)