(Unicode C) SMTP over Multiple Hop SSH

Demonstrates how to send email (using TCP or TLS) tunneled through mulitple-hop SSH. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2 => SmtpServer

The ConnectThroughSsh and UseSsh methods are added in Chilkat version 9.5.0.55 to accomplish this task.

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#include <C_CkSshW.h>
#include <C_CkMailManW.h>
#include <C_CkEmailW.h>

void ChilkatSample(void)
    {
    HCkSshW ssh1;
    BOOL success;
    HCkSshW ssh2;
    HCkMailManW mailman;
    HCkEmailW email;

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    ssh1 = CkSshW_Create();

    // Connect directly to the 1st SSH server.
    success = CkSshW_Connect(ssh1,L"serverssh1.com",22);
    if (success != TRUE) {
        wprintf(L"%s\n",CkSshW_lastErrorText(ssh1));
        CkSshW_Dispose(ssh1);
        return;
    }

    // Authenticate using login/password:
    success = CkSshW_AuthenticatePw(ssh1,L"ssh1Login",L"ssh1Password");
    if (success != TRUE) {
        wprintf(L"%s\n",CkSshW_lastErrorText(ssh1));
        CkSshW_Dispose(ssh1);
        return;
    }

    // Connect through the 1st SSH connection to reach a 2nd SSH server.
    // Note: Any number of SSH connections may be simultaneously tunneled through a single
    // existing SSH connection.
    ssh2 = CkSshW_Create();
    success = CkSshW_ConnectThroughSsh(ssh2,ssh1,L"serverssh2.com",22);
    if (success != TRUE) {
        wprintf(L"%s\n",CkSshW_lastErrorText(ssh2));
        CkSshW_Dispose(ssh1);
        CkSshW_Dispose(ssh2);
        return;
    }

    // Authenticate with ssh2...
    success = CkSshW_AuthenticatePw(ssh2,L"ssh2Login",L"ssh2Password");
    if (success != TRUE) {
        wprintf(L"%s\n",CkSshW_lastErrorText(ssh2));
        CkSshW_Dispose(ssh1);
        CkSshW_Dispose(ssh2);
        return;
    }

    mailman = CkMailManW_Create();

    // Tell the mailman object to connect to the SMTP server though the ssh2 tunnel (which itself is routed through ssh1).
    // The connection looks like this:  Application => ServerSSH1 => ServerSSH2 => SMTPServer
    success = CkMailManW_UseSsh(mailman,ssh2);
    if (success != TRUE) {
        wprintf(L"%s\n",CkMailManW_lastErrorText(mailman));
        CkSshW_Dispose(ssh1);
        CkSshW_Dispose(ssh2);
        CkMailManW_Dispose(mailman);
        return;
    }

    // Set the SMTP server.
    CkMailManW_putSmtpHost(mailman,L"smtp.someserver.com");

    // Set the SMTP login/password (if required)
    CkMailManW_putSmtpUsername(mailman,L"myUsername");
    CkMailManW_putSmtpPassword(mailman,L"myPassword");

    // Create a new email object
    email = CkEmailW_Create();

    CkEmailW_putSubject(email,L"This is a test");
    CkEmailW_putBody(email,L"This is a test");
    CkEmailW_putFrom(email,L"Chilkat Support <support@chilkatsoft.com>");
    success = CkEmailW_AddTo(email,L"Chilkat Admin",L"admin@chilkatsoft.com");

    success = CkMailManW_SendEmail(mailman,email);
    if (success != TRUE) {
        wprintf(L"%s\n",CkMailManW_lastErrorText(mailman));
        CkSshW_Dispose(ssh1);
        CkSshW_Dispose(ssh2);
        CkMailManW_Dispose(mailman);
        CkEmailW_Dispose(email);
        return;
    }

    // Close the connection with the server.  This closes the tunnel through ssh2.
    success = CkMailManW_CloseSmtpConnection(mailman);
    if (success != TRUE) {
        wprintf(L"Connection to SMTP server not closed cleanly.\n");
    }

    wprintf(L"Mail Sent!\n");

    // Close the connection with ssh2.  (This closes the the tunnel through ssh1.)
    // The connection with ssh1 is still alive, and may be used for more connections.
    CkSshW_Disconnect(ssh2);

    CkSshW_Disconnect(ssh1);


    CkSshW_Dispose(ssh1);
    CkSshW_Dispose(ssh2);
    CkMailManW_Dispose(mailman);
    CkEmailW_Dispose(email);

    }