PHP

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.

Chilkat PHP Downloads

Download Chilkat for PHP

Chilkat2 PHP

<?php

use Chilkat2\Ssh;

// 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.

$sshJump = new Ssh();

// Connect and authenticate to the first SSH server (the jump host).
$sshPort = 22;
try {
    $sshJump->Connect('jump.example.com', $sshPort);

    // 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.
    $password = 'mySshPassword';

    $sshJump->AuthenticatePw('jumpUser', $password);

    // Connect to the target SSH server through the jump host.
    $sshTarget = new Ssh();
    $sshTarget->ConnectThroughSsh($sshJump, 'target.example.com', $sshPort);

    // Authenticate to the target server (separate credentials).
    $sshTarget->AuthenticatePw('targetUser', $password);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo "Connected to the target through the jump host.\n";

$sshTarget->Disconnect();
$sshJump->Disconnect();