Xbase++ Requires Chilkat v11.0.0+

SSH Tunnel Inside another SSH Tunnel

See more SSH Tunnel Examples

Demonstrates how to create a TCP/IP socket connection through an SSH tunnel that is dynamic port forwarded through another SSH tunnel. Xbase++

LOCAL nSuccess
LOCAL oTunnel
LOCAL cSshHostname
LOCAL nSshPort
LOCAL oTunnelB
LOCAL oChannel
LOCAL nMaxWaitMs
LOCAL nUseTls
LOCAL nBigEndian
LOCAL oDt
LOCAL nBLocalTime
LOCAL nWaitForThreadExit

nSuccess := 0

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

oTunnel := CreateObject("Chilkat.SshTunnel")

cSshHostname := "www.ssh-serverA.com"
nSshPort := 22

//  Connect to an SSH server and establish the SSH tunnel:
nSuccess := oTunnel:Connect(cSshHostname, nSshPort)
IF (nSuccess == 0)
    ? oTunnel:LastErrorText
    oTunnel:destroy()
    RETURN
ENDIF

//  Authenticate with the SSH server via a login/password
//  or with a public key.  
//  This example demonstrates SSH password authentication.
nSuccess := oTunnel:AuthenticatePw("mySshLogin", "mySshPassword")
IF (nSuccess == 0)
    ? oTunnel:LastErrorText
    oTunnel:destroy()
    RETURN
ENDIF

//  Indicate that the background SSH tunnel thread will behave as a SOCKS proxy server
//  with dynamic port forwarding:
oTunnel: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.

oTunnel:InboundSocksUsername := "chilkat123"
oTunnel:InboundSocksPassword := "password123"

//  Start the listen/accept thread to begin accepting SOCKS proxy client connections.
//  Listen on port 1080.
nSuccess := oTunnel:BeginAccepting(1080)
IF (nSuccess == 0)
    ? oTunnel:LastErrorText
    oTunnel:destroy()
    RETURN
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, Socket, 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.

oTunnelB := CreateObject("Chilkat.Socket")

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

//  Open a new SSH tunnel through the existing tunnel (via what we treat as a SOCKS5 proxy,
//  but it is actually a dynamic port-forwarded SSH tunnel).
nSuccess := oTunnelB:SshOpenTunnel("www.ssh-serverB.com", 22)
IF (nSuccess == 0)
    ? oTunnelB:LastErrorText
    oTunnel:destroy()
    oTunnelB:destroy()
    RETURN
ENDIF

//  Authenticate with ssh-serverB.com
nSuccess := oTunnelB:SshAuthenticatePw("uname", "pwd")
IF (nSuccess == 0)
    ? oTunnelB:LastErrorText
    oTunnel:destroy()
    oTunnelB:destroy()
    RETURN
ENDIF

//  OK, the SSH tunnel (within a tunnel) is setup.  Now open a channel within the tunnel.
//  Once the channel is obtained, the Socket API may
//  be used exactly the same as usual, except all communications
//  are sent through the channel in the SSH tunnel.
//  Any number of channels may be created from the same SSH tunnel.
//  Multiple channels may coexist at the same time.

//  Connect to an NIST time server and read the current date/time
oChannel := CreateObject("Chilkat.Socket")
nMaxWaitMs := 4000
nUseTls := 0
nSuccess := oTunnelB:SshNewChannel("time-c.nist.gov", 37, nUseTls, nMaxWaitMs, oChannel)
IF (nSuccess == 0)
    ? oTunnelB:LastErrorText
    oTunnel:destroy()
    oTunnelB:destroy()
    oChannel:destroy()
    RETURN
ENDIF

//  The time server will send a big-endian 32-bit integer representing
//  the number of seconds since since 00:00 (midnight) 1 January 1900 GMT.
//  The ReceiveInt32 method will receive a 4-byte integer, but returns
//  1 or 0 to indicate success.  If successful, the integer
//  is obtained via the ReceivedInt property.
nBigEndian := 1
nSuccess := oChannel:ReceiveInt32(nBigEndian)
IF (nSuccess == 0)
    ? oChannel:LastErrorText
    oTunnel:destroy()
    oTunnelB:destroy()
    oChannel:destroy()
    RETURN
ENDIF

oDt := CreateObject("Chilkat.CkDateTime")
oDt:SetFromNtpTime(oChannel:ReceivedInt)

//  Show the current local date/time
nBLocalTime := 1
? "Current local date/time: " + oDt:GetAsRfc822(nBLocalTime)

//  Close the SSH channel.
nSuccess := oChannel:Close(nMaxWaitMs)
IF (nSuccess == 0)
    ? oChannel:LastErrorText
    oTunnel:destroy()
    oTunnelB:destroy()
    oChannel:destroy()
    oDt:destroy()
    RETURN
ENDIF

//  Stop the background listen/accept thread:
nWaitForThreadExit := 1
nSuccess := oTunnel:StopAccepting(nWaitForThreadExit)
IF (nSuccess == 0)
    ? oTunnel:LastErrorText
    oTunnel:destroy()
    oTunnelB:destroy()
    oChannel:destroy()
    oDt:destroy()
    RETURN
ENDIF

//  Close the SSH tunnel (would also kick any remaining connected clients).
nSuccess := oTunnel:CloseTunnel(nWaitForThreadExit)
IF (nSuccess == 0)
    ? oTunnel:LastErrorText
    oTunnel:destroy()
    oTunnelB:destroy()
    oChannel:destroy()
    oDt:destroy()
    RETURN
ENDIF

oTunnel:destroy()
oTunnelB:destroy()
oChannel:destroy()
oDt:destroy()