(.NET Core C#) IMAP SSH Tunneling (Port Forwarding)

Demonstrates how to setup and use an SSH tunnel for IMAP.

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

Chilkat.Imap imap = new Chilkat.Imap();

// The SSH hostname may be a hostname or an 
// IP address, such as "192.168.1.108".
// The port is typically 22 (the standard port for SSH).
string sshHostname = "www.mysshserver.com";
int sshPort = 22;

// Connect to an SSH server and establish the SSH tunnel:
bool success = imap.SshOpenTunnel(sshHostname,sshPort);
if (success != true) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

// Authenticate with the SSH server via a login/password
// or with a public key.
// This example demonstrates SSH password authentication.
// Note: This is not authenticating with the IMAP server, it is
// for authenticating with the SSH server, which is separate.
success = imap.SshAuthenticatePw("mySshLogin","mySshPassword");
if (success != true) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

// OK, the SSH tunnel is setup.  The IMAP component may
// be used exactly the same as usual, except all communications
// are sent through the SSH tunnel.

// Connect to an IMAP server via the SSH tunnel.
// Because the SSH tunnel has been previously setup,
// this does not establish a direct connection with the IMAP
// server.  It directs the SSH server to establish the connection.

// In this example, the IMAP server requires SSL/TLS.  The TLS connection
// will be enclosed within the SSH tunnel.
imap.Ssl = true;
imap.Port = 993;
success = imap.Connect("imap.my-imap-server.com");
if (success != true) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

// Authenticate with the IMAP server via the SSH tunnel.
success = imap.Login("myLogin","myPassword");
if (success != true) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

// Select an IMAP mailbox
success = imap.SelectMailbox("Inbox");
if (success != true) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

// How many messages in Inbox?
int msgCount = imap.NumMessages;
if (msgCount == 0) {
    Debug.WriteLine("No messages found.");
    return;
}

int upperBound = 10;
if (msgCount < upperBound) {
    upperBound = msgCount;
}

// Download up to the 1st 10 messages.
int i;
bool bUid = false;
for (i = 1; i <= upperBound; i++) {

    Chilkat.Email email = imap.FetchSingle(i,bUid);
    if (imap.LastMethodSuccess == false) {
        Debug.WriteLine(imap.LastErrorText);
        return;

    }
    else {
        Debug.WriteLine(email.From);
        Debug.WriteLine(email.Subject);
        Debug.WriteLine("----");

    }

}

// Disconnect from the IMAP server.
// The SSH tunnel remains open.
success = imap.Disconnect();
if (success != true) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

// It is possible to re-use the existing SSH tunnel for the next connection:
success = imap.Connect("imap.my-imap-server2.com");
if (success != true) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

// Review the LastErrorText to see that the connection was made via the SSH tunnel:
Debug.WriteLine(imap.LastErrorText);

success = imap.Disconnect();
if (success != true) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

// Finally, close the SSH tunnel.
success = imap.SshCloseTunnel();
if (success != true) {
    Debug.WriteLine(imap.LastErrorText);
    return;
}

Debug.WriteLine("IMAP SSH tunneling example completed.");