Visual FoxPro

IMAP SSH Tunneling (Port Forwarding)

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

LOCAL lnSuccess
LOCAL loImap
LOCAL lcSshHostname
LOCAL lnSshPort
LOCAL lnMsgCount
LOCAL lnUpperBound
LOCAL loEmail
LOCAL i
LOCAL lnBUid

lnSuccess = 0

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

loImap = CreateObject('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).
lcSshHostname = "www.mysshserver.com"
lnSshPort = 22

* Connect to an SSH server and establish the SSH tunnel:
lnSuccess = loImap.SshOpenTunnel(lcSshHostname,lnSshPort)
IF (lnSuccess = 0) THEN
    ? loImap.LastErrorText
    RELEASE loImap
    CANCEL
ENDIF

* 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.
lnSuccess = loImap.SshAuthenticatePw("mySshLogin","mySshPassword")
IF (lnSuccess = 0) THEN
    ? loImap.LastErrorText
    RELEASE loImap
    CANCEL
ENDIF

* 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.
loImap.Ssl = 1
loImap.Port = 993
lnSuccess = loImap.Connect("imap.my-imap-server.com")
IF (lnSuccess = 0) THEN
    ? loImap.LastErrorText
    RELEASE loImap
    CANCEL
ENDIF

* Authenticate with the IMAP server via the SSH tunnel.
lnSuccess = loImap.Login("myLogin","myPassword")
IF (lnSuccess = 0) THEN
    ? loImap.LastErrorText
    RELEASE loImap
    CANCEL
ENDIF

* Select an IMAP mailbox
lnSuccess = loImap.SelectMailbox("Inbox")
IF (lnSuccess = 0) THEN
    ? loImap.LastErrorText
    RELEASE loImap
    CANCEL
ENDIF

* How many messages in Inbox?
lnMsgCount = loImap.NumMessages
IF (lnMsgCount = 0) THEN
    ? "No messages found."
    RELEASE loImap
    CANCEL
ENDIF

lnUpperBound = 10
IF (lnMsgCount < lnUpperBound) THEN
    lnUpperBound = lnMsgCount
ENDIF

* Download up to the 1st 10 messages.
loEmail = CreateObject('Chilkat.Email')

lnBUid = 0
FOR i = 1 TO lnUpperBound

    lnSuccess = loImap.FetchEmail(0,i,lnBUid,loEmail)
    IF (lnSuccess = 0) THEN
        ? loImap.LastErrorText
        RELEASE loImap
        RELEASE loEmail
        CANCEL
    ENDIF

    ? loEmail.From
    ? loEmail.Subject
    ? "----"
NEXT

* Disconnect from the IMAP server.
* The SSH tunnel remains open.
lnSuccess = loImap.Disconnect()
IF (lnSuccess = 0) THEN
    ? loImap.LastErrorText
    RELEASE loImap
    RELEASE loEmail
    CANCEL
ENDIF

* It is possible to re-use the existing SSH tunnel for the next connection:
lnSuccess = loImap.Connect("imap.my-imap-server2.com")
IF (lnSuccess = 0) THEN
    ? loImap.LastErrorText
    RELEASE loImap
    RELEASE loEmail
    CANCEL
ENDIF

* Review the LastErrorText to see that the connection was made via the SSH tunnel:
? loImap.LastErrorText

lnSuccess = loImap.Disconnect()
IF (lnSuccess = 0) THEN
    ? loImap.LastErrorText
    RELEASE loImap
    RELEASE loEmail
    CANCEL
ENDIF

* Finally, close the SSH tunnel.
lnSuccess = loImap.SshCloseTunnel()
IF (lnSuccess = 0) THEN
    ? loImap.LastErrorText
    RELEASE loImap
    RELEASE loEmail
    CANCEL
ENDIF

? "IMAP SSH tunneling example completed."

RELEASE loImap
RELEASE loEmail