Unicode 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.

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#include <C_CkSshTunnelW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkSshTunnelW tunnel;
    int sshPort;
    const wchar_t *infoRequestXml;
    const wchar_t *password;
    const wchar_t *result;
    BOOL waitForThreadExit;

    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.

    tunnel = CkSshTunnelW_Create();

    //  The tunnel forwards accepted local connections to this destination through the SSH server.
    CkSshTunnelW_putDestHostname(tunnel,L"db.internal.example.com");
    CkSshTunnelW_putDestPort(tunnel,5432);

    //  Connect to the SSH server.  This performs the TCP/proxy connection and SSH handshake, but
    //  does not authenticate yet.
    sshPort = 22;
    success = CkSshTunnelW_Connect(tunnel,L"ssh.example.com",sshPort);
    if (success == FALSE) {
        wprintf(L"%s\n",CkSshTunnelW_lastErrorText(tunnel));
        CkSshTunnelW_Dispose(tunnel);
        return;
    }

    //  Begin keyboard-interactive authentication to receive the server's prompt(s).
    infoRequestXml = CkSshTunnelW_startKeyboardAuth(tunnel,L"mySshLogin");
    if (CkSshTunnelW_getLastMethodSuccess(tunnel) == FALSE) {
        wprintf(L"%s\n",CkSshTunnelW_lastErrorText(tunnel));
        CkSshTunnelW_Dispose(tunnel);
        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.
    password = L"mySshPassword";

    //  Submit the response (typically the password).  The returned XML indicates the next prompt or
    //  the final result.
    result = CkSshTunnelW_continueKeyboardAuth(tunnel,password);
    if (CkSshTunnelW_getLastMethodSuccess(tunnel) == FALSE) {
        wprintf(L"%s\n",CkSshTunnelW_lastErrorText(tunnel));
        CkSshTunnelW_Dispose(tunnel);
        return;
    }

    wprintf(L"%s\n",result);

    waitForThreadExit = TRUE;
    success = CkSshTunnelW_CloseTunnel(tunnel,waitForThreadExit);
    if (success == FALSE) {
        wprintf(L"%s\n",CkSshTunnelW_lastErrorText(tunnel));
        CkSshTunnelW_Dispose(tunnel);
        return;
    }



    CkSshTunnelW_Dispose(tunnel);

    }