React Native

IMAP over Multiple Hop SSH

Demonstrates how to read IMAP email (using TCP or TLS) tunneled through mulitple-hop SSH. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2 => IMAPServer

The ConnectThroughSsh and UseSsh methods are added in Chilkat version 9.5.0.55 to accomplish this task.

React Native

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

async function chilkatExample() {
  // This example assumes the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  const ssh1 = new Ssh();

  // Connect directly to the 1st SSH server.
  try {
    await ssh1.connectAsync('serverssh1.com', 22);
  } catch {
    console.log(ssh1.lastErrorText);
    return;
  }

  // Authenticate using login/password:
  try {
    await ssh1.authenticatePwAsync('ssh1Login', 'ssh1Password');
  } catch {
    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.
  const ssh2 = new Ssh();
  try {
    await ssh2.connectThroughSshAsync(ssh1, 'serverssh2.com', 22);
  } catch {
    console.log(ssh2.lastErrorText);
    return;
  }

  // Authenticate with ssh2...
  try {
    await ssh2.authenticatePwAsync('ssh2Login', 'ssh2Password');
  } catch {
    console.log(ssh2.lastErrorText);
    return;
  }

  const imap = new Imap();

  // Tell the IMAP object to connect to the IMAP server though the ssh2 tunnel (which itself is routed through ssh1).
  // The connection looks like this:  Application => ServerSSH1 => ServerSSH2 => IMAPServer
  try {
    imap.useSsh(ssh2);
  } catch {
    console.log(imap.lastErrorText);
    return;
  }

  imap.ssl = true;
  imap.port = 993;

  // Connect to an IMAP server (through the multi-hop SSH tunnel)
  try {
    await imap.connectAsync('imap.someimapserver.com');
  } catch {
    console.log(imap.lastErrorText);
    return;
  }

  // Login
  try {
    await imap.loginAsync('myLogin', 'myPassword');
  } catch {
    console.log(imap.lastErrorText);
    return;
  }

  // Do whatever needs to be done...  for example,

  // Create the new email folder (sub-mailbox) on the IMAP server.
  // If no folder path is provided, the new folder is a sub-mailbox of Inbox.
  try {
    await imap.createMailboxAsync('newFolder');
  } catch {
    console.log(imap.lastErrorText);
    return;
  }

  console.log('Success.');

  // Close the connection with the IMAP server.  (This closes the tunnel through ssh2)
  // The connection with ssh2 is still alive, and may be used for more connections.
  await imap.disconnectAsync();

  // 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();
}