Swift Requires Chilkat v11.0.0+

POP3 SSH Tunneling (Port Forwarding)

Demonstrates how to connect to a POP3 server through an SSH tunnel. Reads a POP3 mailbox and display the FROM and SUBJECT header fields of each email. Swift

func chilkatTest() {
    var success: Bool = false

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

    //  The mailman object is used for receiving (POP3) 
    //  and sending (SMTP) email.
    let mailman = CkoMailMan()!

    //  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).
    var sshHostname: String? = "sftp.example.com"
    var sshPort: Int = 22

    //  Connect to an SSH server and establish the SSH tunnel:
    success = mailman.sshOpenTunnel(sshHostname: sshHostname, sshPort: sshPort)
    if success == false {
        print("\(mailman.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 POP3 server, it is
    //  for authenticating with the SSH server, which is separate.
    success = mailman.sshAuthenticatePw(sshLogin: "ssh_login", sshPassword: "ssh_password")
    if success == false {
        print("\(mailman.lastErrorText!)")
        return
    }

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

    //  The SSH tunnel may be kept open for any number of 
    //  POP3 connections.  

    //  Set the POP3 server's hostname
    mailman.mailHost = "mail.my-pop3-server.com"

    //  Set the POP3 settings for your POP3 server:
    mailman.popUsername = "pop3_login"
    mailman.popPassword = "pop3_password"
    mailman.mailPort = 995
    mailman.popSsl = true

    //  Connect to the POP3 server through the already-established SSH tunnel:
    success = mailman.pop3BeginSession()
    if success == false {
        print("\(mailman.lastErrorText!)")
        return
    }

    //  A visual inspection of the LastErrorText after
    //  a successful POP3 connection will confirm the SSH tunneling.
    //  Note: If the POP3 connection uses SSL/TLS, then the SSL/TLS 
    //  secure channel will be wrapped within the SSH tunnel.
    print("\(mailman.lastErrorText!)")

    //  How many messages are in the POP3 inbox?
    var numToDownload: Int = mailman.getMailboxCount().intValue
    if numToDownload > 5 {
        numToDownload = 5
    }

    if numToDownload == 0 {
        print("No messages in the POP3 inbox.")
        return
    }

    //  Download a max of 5 messages
    var i: Int
    let email = CkoEmail()!
    for i = 1; i <= numToDownload; i++ {
        success = mailman.fetchOne(headerOnly: false, numBodyLines: 0, msgNum: i, email: email)
        if success == false {
            print("\(mailman.lastErrorText!)")
            return
        }

        print("\(email.from!)")
        print("\(email.subject!)")
        print("----")
    }

    //  Close the connection with the POP3 server, leaving the SSH tunnel open for subsequent POP3 connections.
    success = mailman.pop3EndSession()
    if success == false {
        print("\(mailman.lastErrorText!)")
        return
    }

    //  Try connecting to a different POP3 server through the same aleady setup SSH tunnel:
    //  Set the POP3 server's hostname
    mailman.mailHost = "mail.my-pop3-server2.com"

    //  Set the POP3 settings for your POP3 server:
    mailman.popUsername = "pop3_login2"
    mailman.popPassword = "pop3_password2"
    mailman.mailPort = 110
    mailman.popSsl = false

    success = mailman.pop3BeginSession()
    if success == false {
        print("\(mailman.lastErrorText!)")
        return
    }

    //  Review the LastErrorText to see that the connection was made via the SSH tunnel:
    print("\(mailman.lastErrorText!)")

    success = mailman.pop3EndSession()
    if success == false {
        print("\(mailman.lastErrorText!)")
        return
    }

    //  Close the SSH tunnel.
    success = mailman.sshCloseTunnel()
    if success == false {
        print("\(mailman.lastErrorText!)")
        return
    }


}