React Native

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 React Native Downloads

Download Chilkat for React Native

React Native

import { Ssh } from '@chilkat/react-native'

async function chilkatExample() {
  // 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.

  const sshJump = new Ssh();

  // Connect and authenticate to the first SSH server (the jump host).
  const sshPort = 22;
  try {
    await sshJump.connectAsync('jump.example.com', sshPort);
  } catch {
    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.
  const password = 'mySshPassword';

  try {
    await sshJump.authenticatePwAsync('jumpUser', password);
  } catch {
    console.log(sshJump.lastErrorText);
    return;
  }

  // Connect to the target SSH server through the jump host.
  const sshTarget = new Ssh();
  try {
    await sshTarget.connectThroughSshAsync(sshJump, 'target.example.com', sshPort);
  } catch {
    console.log(sshTarget.lastErrorText);
    return;
  }

  // Authenticate to the target server (separate credentials).
  try {
    await sshTarget.authenticatePwAsync('targetUser', password);
  } catch {
    console.log(sshTarget.lastErrorText);
    return;
  }

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

  sshTarget.disconnect();
  sshJump.disconnect();
}