PureBasic

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. PureBasic

IncludeFile "CkSshTunnel.pb"
IncludeFile "CkHttp.pb"

Procedure ChilkatExample()

    success.i = 0

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

    success = 0

    tunnel.i = CkSshTunnel::ckCreate()
    If tunnel.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    sshHostname.s = "sftp.example.com"
    sshPort.i = 22

    ; Connect to an SSH server and establish the SSH tunnel:
    success = CkSshTunnel::ckConnect(tunnel,sshHostname,sshPort)
    If success <> 1
        Debug CkSshTunnel::ckLastErrorText(tunnel)
        CkSshTunnel::ckDispose(tunnel)
        ProcedureReturn
    EndIf

    ; Authenticate with the SSH server via a login/password
    ; or with a public key.  
    ; This example demonstrates SSH password authentication.
    success = CkSshTunnel::ckAuthenticatePw(tunnel,"mySshLogin","mySshPassword")
    If success <> 1
        Debug CkSshTunnel::ckLastErrorText(tunnel)
        CkSshTunnel::ckDispose(tunnel)
        ProcedureReturn
    EndIf

    ; Indicate that the background SSH tunnel thread will behave as a SOCKS proxy server
    ; with dynamic port forwarding:
    CkSshTunnel::setCkDynamicPortForwarding(tunnel, 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.

    CkSshTunnel::setCkInboundSocksUsername(tunnel, "chilkat123")
    CkSshTunnel::setCkInboundSocksPassword(tunnel, "password123")

    ; Start the listen/accept thread to begin accepting SOCKS proxy client connections.
    ; Listen on port 1080.
    success = CkSshTunnel::ckBeginAccepting(tunnel,1080)
    If success <> 1
        Debug CkSshTunnel::ckLastErrorText(tunnel)
        CkSshTunnel::ckDispose(tunnel)
        ProcedureReturn
    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:
    url.s = "https://www.ethereum.org/"

    http.i = CkHttp::ckCreate()
    If http.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Indicate that the HTTP object is to use our portable SOCKS proxy/SSH tunnel running in our background thread.
    CkHttp::setCkSocksHostname(http, "localhost")
    CkHttp::setCkSocksPort(http, 1080)
    CkHttp::setCkSocksVersion(http, 5)
    CkHttp::setCkSocksUsername(http, "chilkat123")
    CkHttp::setCkSocksPassword(http, "password123")

    CkHttp::setCkSendCookies(http, 1)
    CkHttp::setCkSaveCookies(http, 1)
    CkHttp::setCkCookieDir(http, "memory")

    ; Do the HTTPS page fetch (through the SSH tunnel)
    html.s = CkHttp::ckQuickGetStr(http,url)
    If CkHttp::ckLastMethodSuccess(http) <> 1
        Debug CkHttp::ckLastErrorText(http)
        CkSshTunnel::ckDispose(tunnel)
        CkHttp::ckDispose(http)
        ProcedureReturn
    EndIf

    ; Stop the background listen/accept thread:
    waitForThreadExit.i = 1
    success = CkSshTunnel::ckStopAccepting(tunnel,waitForThreadExit)
    If success <> 1
        Debug CkSshTunnel::ckLastErrorText(tunnel)
        CkSshTunnel::ckDispose(tunnel)
        CkHttp::ckDispose(http)
        ProcedureReturn
    EndIf

    ; Close the SSH tunnel (would also kick any remaining connected clients).
    success = CkSshTunnel::ckCloseTunnel(tunnel,waitForThreadExit)
    If success <> 1
        Debug CkSshTunnel::ckLastErrorText(tunnel)
        CkSshTunnel::ckDispose(tunnel)
        CkHttp::ckDispose(http)
        ProcedureReturn
    EndIf



    CkSshTunnel::ckDispose(tunnel)
    CkHttp::ckDispose(http)


    ProcedureReturn
EndProcedure