(PureBasic) SSH Tunnel with Dynamic Port Forwarding

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.

Chilkat PureBasic Module Download Chilkat PureBasic Module

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

Procedure ChilkatExample()

    ; Starting in v9.5.0.49, all Chilkat classes can be unlocked at once at the beginning of a program
    ; by calling UnlockBundle.  It requires a Bundle unlock code.
    chilkatGlob.i = CkGlobal::ckCreate()
    If chilkatGlob.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success.i = CkGlobal::ckUnlockBundle(chilkatGlob,"Anything for 30-day trial.")
    If success <> 1
        Debug CkGlobal::ckLastErrorText(chilkatGlob)
        CkGlobal::ckDispose(chilkatGlob)
        ProcedureReturn
    EndIf

    ; This example requires Chilkat version 9.5.0.50 or greater.
    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)
        CkGlobal::ckDispose(chilkatGlob)
        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)
        CkGlobal::ckDispose(chilkatGlob)
        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)
        CkGlobal::ckDispose(chilkatGlob)
        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)
        CkGlobal::ckDispose(chilkatGlob)
        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)
        CkGlobal::ckDispose(chilkatGlob)
        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)
        CkGlobal::ckDispose(chilkatGlob)
        CkSshTunnel::ckDispose(tunnel)
        CkHttp::ckDispose(http)
        ProcedureReturn
    EndIf



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


    ProcedureReturn
EndProcedure