(C) POP3 over Multiple Hop SSH

Demonstrates how to read POP3 email (using TCP or TLS) tunneled through mulitple-hop SSH. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2 => POP3Server

Chilkat C/C++ Library Downloads
MS Visual C/C++ Linux/CentOS C/C++ Alpine Linux C/C++ MAC OS X C/C++	armhf/aarch64 C/C++ C++ Builder iOS C/C++ Android C/C++	Solaris C/C++ MinGW C/C++

#include <C_CkSsh.h>
#include <C_CkMailMan.h>
#include <C_CkEmail.h>

void ChilkatSample(void)
    {
    HCkSsh ssh1;
    BOOL success;
    HCkSsh ssh2;
    HCkMailMan mailman;
    int numMessages;
    int i;
    HCkEmail email;

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

    ssh1 = CkSsh_Create();

    // Connect directly to the 1st SSH server.
    success = CkSsh_Connect(ssh1,"serverssh1.com",22);
    if (success != TRUE) {
        printf("%s\n",CkSsh_lastErrorText(ssh1));
        CkSsh_Dispose(ssh1);
        return;
    }

    // Authenticate using login/password:
    success = CkSsh_AuthenticatePw(ssh1,"ssh1Login","ssh1Password");
    if (success != TRUE) {
        printf("%s\n",CkSsh_lastErrorText(ssh1));
        CkSsh_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 = CkSsh_Create();
    success = CkSsh_ConnectThroughSsh(ssh2,ssh1,"serverssh2.com",22);
    if (success != TRUE) {
        printf("%s\n",CkSsh_lastErrorText(ssh2));
        CkSsh_Dispose(ssh1);
        CkSsh_Dispose(ssh2);
        return;
    }

    // Authenticate with ssh2...
    success = CkSsh_AuthenticatePw(ssh2,"ssh2Login","ssh2Password");
    if (success != TRUE) {
        printf("%s\n",CkSsh_lastErrorText(ssh2));
        CkSsh_Dispose(ssh1);
        CkSsh_Dispose(ssh2);
        return;
    }

    mailman = CkMailMan_Create();

    // Tell the mailman object to connect to the POP3 server though the ssh2 tunnel (which itself is routed through ssh1).
    // The connection looks like this:  Application => ServerSSH1 => ServerSSH2 => POP3Server
    success = CkMailMan_UseSsh(mailman,ssh2);
    if (success != TRUE) {
        printf("%s\n",CkMailMan_lastErrorText(mailman));
        CkSsh_Dispose(ssh1);
        CkSsh_Dispose(ssh2);
        CkMailMan_Dispose(mailman);
        return;
    }

    // Set the POP3 server's hostname
    CkMailMan_putMailHost(mailman,"pop.someMailServer.com");

    // Set the POP3 login/password.
    CkMailMan_putPopUsername(mailman,"myLogin");
    CkMailMan_putPopPassword(mailman,"myPassword");

    // Establish the POP3 connection through the ssh2 tunnel.
    success = CkMailMan_Pop3BeginSession(mailman);
    if (success != TRUE) {
        printf("%s\n",CkMailMan_lastErrorText(mailman));
        CkSsh_Dispose(ssh1);
        CkSsh_Dispose(ssh2);
        CkMailMan_Dispose(mailman);
        return;
    }

    // Get the number of messages in the mailbox.
    numMessages = CkMailMan_GetMailboxCount(mailman);

    i = 1;

    while (i <= numMessages) {

        email = CkMailMan_FetchByMsgnum(mailman,i);
        if (CkMailMan_getLastMethodSuccess(mailman) != TRUE) {
            printf("%s\n",CkMailMan_lastErrorText(mailman));
            CkSsh_Dispose(ssh1);
            CkSsh_Dispose(ssh2);
            CkMailMan_Dispose(mailman);
            return;
        }

        printf("%s: %s\n\n",CkEmail_ck_from(email),CkEmail_subject(email));
        CkEmail_Dispose(email);

        i = i + 1;
    }

    // Close the connection with the POP3 server.  (This closes the tunnel through ssh2)
    // The connection with ssh2 is still alive, and may be used for more connections.
    success = CkMailMan_Pop3EndSession(mailman);

    // 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.

    CkSsh_Disconnect(ssh2);

    CkSsh_Disconnect(ssh1);


    CkSsh_Dispose(ssh1);
    CkSsh_Dispose(ssh2);
    CkMailMan_Dispose(mailman);

    }