C++

SSH Tunnel Authenticate with a SecureString Password and Private Key

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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C++

#include <CkSshTunnel.h>
#include <CkSshKey.h>
#include <CkSecureString.h>

void ChilkatSample(void)
    {
    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.

    CkSshTunnel tunnel;

    //  The tunnel forwards accepted local connections to this destination through the SSH server.
    tunnel.put_DestHostname("db.internal.example.com");
    tunnel.put_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) {
        std::cout << tunnel.lastErrorText() << "\r\n";
        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 char *password = "mySshPassword";

    //  Load the SSH private key.  LoadText reads the file's text, which is then imported.
    CkSshKey privKey;
    const char *keyText = privKey.loadText("qa_data/id_rsa");
    if (privKey.get_LastMethodSuccess() == false) {
        std::cout << privKey.lastErrorText() << "\r\n";
        return;
    }

    success = privKey.FromOpenSshPrivateKey(keyText);
    if (success == false) {
        std::cout << privKey.lastErrorText() << "\r\n";
        return;
    }

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

    success = tunnel.AuthenticateSecPwPk(secureLogin,securePassword,privKey);
    if (success == false) {
        std::cout << tunnel.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Authenticated." << "\r\n";

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

    bool waitForThreadExit = true;
    success = tunnel.CloseTunnel(waitForThreadExit);
    if (success == false) {
        std::cout << tunnel.lastErrorText() << "\r\n";
        return;
    }
    }