SSH Tunnel Authenticate with a SecureString Password and Private Key

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Demonstrates the Chilkat SshTunnel.AuthenticateSecPwPk method, which authenticates using SecureString login and password objects together with a private key. The third argument is the SshKey private key.

Note: The private-key path is relative to the application's current working directory. Absolute paths may also be used. Supply the path to your own key file.

Background: This is the SecureString form of two-factor tunnel authentication: the password is held encrypted in memory and combined with a private key for servers that require both. It is the most protective option when a deployment mandates two-factor SSH and you also want to minimize plaintext credential exposure in a long-running process.

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bool success = false;

//  Demonstrates the SshTunnel.AuthenticateSecPwPk method, which authenticates using SecureString
//  login and password objects together with a private key.  The 1st argument is the username, the
//  2nd is the password, and the 3rd is an SshKey private key.

Chilkat.SshTunnel tunnel = new Chilkat.SshTunnel();

//  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.
int sshPort = 22;
success = tunnel.Connect("ssh.example.com",sshPort);
if (success == false) {
    Debug.WriteLine(tunnel.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.
string password = "mySshPassword";

//  Load the SSH private key.  LoadText reads the file's text, which is then imported.
Chilkat.SshKey privKey = new Chilkat.SshKey();
string keyText = privKey.LoadText("qa_data/id_rsa");
if (privKey.LastMethodSuccess == false) {
    Debug.WriteLine(privKey.LastErrorText);
    return;
}

success = privKey.FromOpenSshPrivateKey(keyText);
if (success == false) {
    Debug.WriteLine(privKey.LastErrorText);
    return;
}

//  Place the login and password into SecureString objects.
Chilkat.SecureString secureLogin = new Chilkat.SecureString();
secureLogin.Append("mySshLogin");
Chilkat.SecureString securePassword = new Chilkat.SecureString();
securePassword.Append(password);

success = tunnel.AuthenticateSecPwPk(secureLogin,securePassword,privKey);
if (success == false) {
    Debug.WriteLine(tunnel.LastErrorText);
    return;
}

Debug.WriteLine("Authenticated.");

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

bool waitForThreadExit = true;
success = tunnel.CloseTunnel(waitForThreadExit);
if (success == false) {
    Debug.WriteLine(tunnel.LastErrorText);
    return;
}