C++

Continue SSH Tunnel Keyboard-Interactive Authentication

Demonstrates the Chilkat SshTunnel.ContinueKeyboardAuth method, which submits a response to a keyboard-interactive prompt. The only argument is the response text; for a request with multiple prompts, an XML response is supplied instead. It returns XML indicating the next prompt or the final result.

Background: This is the second half of the exchange started by StartKeyboardAuth. A server may issue several rounds of prompts, so a robust client loops: submit answers, read the returned XML, and continue until it sees success or failure. On success, BeginAccepting still must be called before the tunnel forwards traffic.

Chilkat C++ Downloads

Download Chilkat for C++

C++

#include <CkSshTunnel.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  Demonstrates the SshTunnel.ContinueKeyboardAuth method, which submits a response to a
    //  keyboard-interactive prompt.  The only argument is the response.  For multiple prompts, an XML
    //  response is supplied instead.

    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;
    }

    //  Begin keyboard-interactive authentication to receive the server's prompt(s).
    const char *infoRequestXml = tunnel.startKeyboardAuth("mySshLogin");
    if (tunnel.get_LastMethodSuccess() == 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";

    //  Submit the response (typically the password).  The returned XML indicates the next prompt or
    //  the final result.
    const char *result = tunnel.continueKeyboardAuth(password);
    if (tunnel.get_LastMethodSuccess() == false) {
        std::cout << tunnel.lastErrorText() << "\r\n";
        return;
    }

    std::cout << result << "\r\n";

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