JavaScript

Connect to an SSH Server Through Another (Jump Host)

Demonstrates the Chilkat Ssh.ConnectThroughSsh method, which connects to a second SSH server through an already connected and authenticated Ssh object. The first argument is the first (jump-host) Ssh object, and the second and third are the destination hostname and port.

Background: This is SSH chaining through a "jump host" (bastion): the application connects to a reachable gateway, then tunnels onward to a target that is only accessible from inside the network. Each hop is authenticated separately with its own credentials. The result is a normal Ssh object for the target that happens to be routed through the first connection.

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

JavaScript

var success = false;

//  Demonstrates the Ssh.ConnectThroughSsh method, which connects to a second SSH server through
//  an already connected and authenticated Ssh object (a jump host).  The 1st argument is the
//  first Ssh object, and the 2nd and 3rd are the destination hostname and port.

var sshJump = new CkSsh();

//  Connect and authenticate to the first SSH server (the jump host).
var sshPort = 22;
success = sshJump.Connect("jump.example.com",sshPort);
if (success == false) {
    console.log(sshJump.LastErrorText);
    return;
}

//  Normally you would not hard-code the password in source.  You should instead obtain it
//  from an interactive prompt, environment variable, or a secrets vault.
var password = "mySshPassword";

success = sshJump.AuthenticatePw("jumpUser",password);
if (success == false) {
    console.log(sshJump.LastErrorText);
    return;
}

//  Connect to the target SSH server through the jump host.
var sshTarget = new CkSsh();
success = sshTarget.ConnectThroughSsh(sshJump,"target.example.com",sshPort);
if (success == false) {
    console.log(sshTarget.LastErrorText);
    return;
}

//  Authenticate to the target server (separate credentials).
success = sshTarget.AuthenticatePw("targetUser",password);
if (success == false) {
    console.log(sshTarget.LastErrorText);
    return;
}

console.log("Connected to the target through the jump host.");

sshTarget.Disconnect();
sshJump.Disconnect();