(Node.js) TCP or TLS over Multiple Hop SSH to Remote Server

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.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

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

    var ssh1 = new chilkat.Ssh();

    // Connect directly to the 1st SSH server.
    var success = ssh1.Connect("serverssh1.com",22);
    if (success !== true) {
        console.log(ssh1.LastErrorText);
        return;
    }

    // Authenticate using login/password:
    success = ssh1.AuthenticatePw("ssh1Login","ssh1Password");
    if (success !== true) {
        console.log(ssh1.LastErrorText);
        return;
    }

    // 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.
    var ssh2 = new chilkat.Ssh();
    success = ssh2.ConnectThroughSsh(ssh1,"serverssh2.com",22);
    if (success !== true) {
        console.log(ssh2.LastErrorText);
        return;
    }

    // Authenticate with ssh2...
    success = ssh2.AuthenticatePw("ssh2Login","ssh2Password");
    if (success !== true) {
        console.log(ssh2.LastErrorText);
        return;
    }

    var socket = new chilkat.Socket();

    // 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) {
        console.log(socket.LastErrorText);
        return;
    }

    // Connect using TLS to www.chilkatsoft.com
    // We could also tunnel a bare TCP connection by specifying port 80 with useTls = false.
    var useTls = true;
    var maxWaitMillisec = 20000;
    success = socket.Connect("www.chilkatsoft.com",443,useTls,maxWaitMillisec);
    if (success !== true) {
        console.log(socket.LastErrorText);
        return;
    }

    // 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.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) {
        console.log(socket.LastErrorText);
        return;
    }

    // Wait a maximum of 4 seconds while no data is forthcoming:
    socket.MaxReadIdleMs = 4000;

    // Get the 1st response line, which should be "HTTP/1.1 200 OK"
    var responseStatusLine = socket.ReceiveToCRLF();
    if (socket.LastMethodSuccess !== true) {
        console.log(socket.LastErrorText);
        return;
    }

    console.log("StatusLine: " + responseStatusLine);

    // Now get the 1st line of the response header:
    var responseHeaderLine = socket.ReceiveToCRLF();
    if (socket.LastMethodSuccess !== true) {
        console.log(socket.LastErrorText);
        return;
    }

    console.log("HeaderLine: " + responseHeaderLine);

    // Now read the remainder of the response header by reading until a double CRLF is seen:
    var remainderOfHeader = socket.ReceiveUntilMatch("\r\n\r\n");
    if (socket.LastMethodSuccess !== true) {
        console.log(socket.LastErrorText);
        return;
    }

    console.log("Remainder: " + remainderOfHeader);

    // 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();

}

chilkatExample();