Dart

SSH Tunnel Authenticate with a Password

Demonstrates the Chilkat SshTunnel.AuthenticatePw method, which authenticates the SSH connection with a login name and password. The first argument is the login and the second is the password. Connect first, and call BeginAccepting afterward.

Background: Password authentication is the simplest option, but the password is a secret and should never be a hard-coded literal — obtain it from an interactive prompt, an environment variable, or a secrets vault. Public-key authentication is generally preferred for the unattended, long-running services that tunnels often are.

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Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // Demonstrates the SshTunnel.AuthenticatePw method, which authenticates the SSH connection with
  // a login name and password.  The 1st argument is the login and the 2nd is the password.

  final tunnel = CkSshTunnel();

  // The tunnel forwards accepted local connections to this destination through the SSH server.
  tunnel.destHostname = 'db.internal.example.com';
  tunnel.destPort = 5432;

  // Connect to the SSH server.  This performs the TCP/proxy connection and SSH handshake, but
  // does not authenticate yet.
  final sshPort = 22;
  try {
    tunnel.connect('ssh.example.com', sshPort);
  } on ChilkatException catch (e) {
    print(e.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.
  final password = 'mySshPassword';

  try {
    tunnel.authenticatePw('mySshLogin', password);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('Authenticated.');

  // After authenticating, call BeginAccepting to start listening for local connections to forward.

  final waitForThreadExit = true;
  try {
    tunnel.closeTunnel(waitForThreadExit);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }
}