Visual FoxPro

SSH Tunnel with Dynamic Port Forwarding

See more SSH Examples

Demonstrates how to start a background thread that runs a portable SSH tunnel w/ dynamic port forwarding that the foreground thread can use for establishing connections through an SSH tunnel. Visual FoxPro

LOCAL lnSuccess
LOCAL loTunnel
LOCAL lcSshHostname
LOCAL lnSshPort
LOCAL lcUrl
LOCAL loHttp
LOCAL lcHtml
LOCAL lnWaitForThreadExit

lnSuccess = 0

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

lnSuccess = 0

loTunnel = CreateObject('Chilkat.SshTunnel')

lcSshHostname = "sftp.example.com"
lnSshPort = 22

* Connect to an SSH server and establish the SSH tunnel:
lnSuccess = loTunnel.Connect(lcSshHostname,lnSshPort)
IF (lnSuccess <> 1) THEN
    ? loTunnel.LastErrorText
    RELEASE loTunnel
    CANCEL
ENDIF

* Authenticate with the SSH server via a login/password
* or with a public key.  
* This example demonstrates SSH password authentication.
lnSuccess = loTunnel.AuthenticatePw("mySshLogin","mySshPassword")
IF (lnSuccess <> 1) THEN
    ? loTunnel.LastErrorText
    RELEASE loTunnel
    CANCEL
ENDIF

* Indicate that the background SSH tunnel thread will behave as a SOCKS proxy server
* with dynamic port forwarding:
loTunnel.DynamicPortForwarding = 1

* We may optionally require that connecting clients authenticate with our SOCKS proxy server.
* To do this, set an inbound username/password.  Any connecting clients would be required to 
* use SOCKS5 with the correct username/password.
* If no inbound username/password is set, then our SOCKS proxy server will accept both
* SOCKS4 and SOCKS5 unauthenticated connections.

loTunnel.InboundSocksUsername = "chilkat123"
loTunnel.InboundSocksPassword = "password123"

* Start the listen/accept thread to begin accepting SOCKS proxy client connections.
* Listen on port 1080.
lnSuccess = loTunnel.BeginAccepting(1080)
IF (lnSuccess <> 1) THEN
    ? loTunnel.LastErrorText
    RELEASE loTunnel
    CANCEL
ENDIF

* Now that a background thread is running a SOCKS proxy server that forwards connections
* through an SSH tunnel, it is possible to use any Chilkat implemented protocol that is SOCKS capable,
* such as HTTP, POP3, SMTP, IMAP, FTP, etc.  The protocol may use SSL/TLS because the SSL/TLS
* will be passed through the SSH tunnel to the end-destination.  Also, any number of simultaneous
* connections may be routed through the SSH tunnel.

* For this example, let's do a simple HTTPS request:
lcUrl = "https://www.ethereum.org/"

loHttp = CreateObject('Chilkat.Http')

* Indicate that the HTTP object is to use our portable SOCKS proxy/SSH tunnel running in our background thread.
loHttp.SocksHostname = "localhost"
loHttp.SocksPort = 1080
loHttp.SocksVersion = 5
loHttp.SocksUsername = "chilkat123"
loHttp.SocksPassword = "password123"

loHttp.SendCookies = 1
loHttp.SaveCookies = 1
loHttp.CookieDir = "memory"

* Do the HTTPS page fetch (through the SSH tunnel)
lcHtml = loHttp.QuickGetStr(lcUrl)
IF (loHttp.LastMethodSuccess <> 1) THEN
    ? loHttp.LastErrorText
    RELEASE loTunnel
    RELEASE loHttp
    CANCEL
ENDIF

* Stop the background listen/accept thread:
lnWaitForThreadExit = 1
lnSuccess = loTunnel.StopAccepting(lnWaitForThreadExit)
IF (lnSuccess <> 1) THEN
    ? loTunnel.LastErrorText
    RELEASE loTunnel
    RELEASE loHttp
    CANCEL
ENDIF

* Close the SSH tunnel (would also kick any remaining connected clients).
lnSuccess = loTunnel.CloseTunnel(lnWaitForThreadExit)
IF (lnSuccess <> 1) THEN
    ? loTunnel.LastErrorText
    RELEASE loTunnel
    RELEASE loHttp
    CANCEL
ENDIF

RELEASE loTunnel
RELEASE loHttp