(PowerBuilder) SSH Tunnel Inside another SSH Tunnel

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

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integer li_rc
oleobject loo_Tunnel
string ls_SshHostname
integer li_SshPort
integer li_Success
oleobject loo_TunnelB
oleobject loo_Channel
integer li_MaxWaitMs
integer li_UseTls
integer li_BigEndian
oleobject loo_Dt
integer li_BLocalTime
integer li_WaitForThreadExit

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

// This example requires Chilkat version 9.5.0.50 or greater.
loo_Tunnel = create oleobject
li_rc = loo_Tunnel.ConnectToNewObject("Chilkat_9_5_0.SshTunnel")
if li_rc < 0 then
    destroy loo_Tunnel
    MessageBox("Error","Connecting to COM object failed")
    return
end if

ls_SshHostname = "www.ssh-serverA.com"
li_SshPort = 22

// Connect to an SSH server and establish the SSH tunnel:
li_Success = loo_Tunnel.Connect(ls_SshHostname,li_SshPort)
if li_Success <> 1 then
    Write-Debug loo_Tunnel.LastErrorText
    destroy loo_Tunnel
    return
end if

// Authenticate with the SSH server via a login/password
// or with a public key.  
// This example demonstrates SSH password authentication.
li_Success = loo_Tunnel.AuthenticatePw("mySshLogin","mySshPassword")
if li_Success <> 1 then
    Write-Debug loo_Tunnel.LastErrorText
    destroy loo_Tunnel
    return
end if

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

loo_Tunnel.InboundSocksUsername = "chilkat123"
loo_Tunnel.InboundSocksPassword = "password123"

// Start the listen/accept thread to begin accepting SOCKS proxy client connections.
// Listen on port 1080.
li_Success = loo_Tunnel.BeginAccepting(1080)
if li_Success <> 1 then
    Write-Debug loo_Tunnel.LastErrorText
    destroy loo_Tunnel
    return
end if

// 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.

loo_TunnelB = create oleobject
li_rc = loo_TunnelB.ConnectToNewObject("Chilkat_9_5_0.Socket")

// Indicate that the socket object is to use our portable SOCKS proxy/SSH tunnel running in our background thread.
loo_TunnelB.SocksHostname = "localhost"
loo_TunnelB.SocksPort = 1080
loo_TunnelB.SocksVersion = 5
loo_TunnelB.SocksUsername = "chilkat123"
loo_TunnelB.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).
li_Success = loo_TunnelB.SshOpenTunnel("www.ssh-serverB.com",22)
if li_Success <> 1 then
    Write-Debug loo_TunnelB.LastErrorText
    destroy loo_Tunnel
    destroy loo_TunnelB
    return
end if

// Authenticate with ssh-serverB.com
li_Success = loo_TunnelB.SshAuthenticatePw("uname","pwd")
if li_Success <> 1 then
    Write-Debug loo_TunnelB.LastErrorText
    destroy loo_Tunnel
    destroy loo_TunnelB
    return
end if

// 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

li_MaxWaitMs = 4000
li_UseTls = 0
loo_Channel = loo_TunnelB.SshOpenChannel("time-c.nist.gov",37,li_UseTls,li_MaxWaitMs)
if loo_TunnelB.LastMethodSuccess = 0 then
    Write-Debug loo_TunnelB.LastErrorText
    destroy loo_Tunnel
    destroy loo_TunnelB
    return
end if

// 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.
li_BigEndian = 1
li_Success = loo_Channel.ReceiveInt32(li_BigEndian)
if li_Success <> 1 then
    Write-Debug loo_Channel.LastErrorText
    destroy loo_Channel
    destroy loo_Tunnel
    destroy loo_TunnelB
    return
end if

loo_Dt = create oleobject
li_rc = loo_Dt.ConnectToNewObject("Chilkat_9_5_0.CkDateTime")

loo_Dt.SetFromNtpTime(loo_Channel.ReceivedInt)

// Show the current local date/time
li_BLocalTime = 1
Write-Debug "Current local date/time: " + loo_Dt.GetAsRfc822(li_BLocalTime)

// Close the SSH channel.
li_Success = loo_Channel.Close(li_MaxWaitMs)
if li_Success <> 1 then
    Write-Debug loo_Channel.LastErrorText
    destroy loo_Channel
    destroy loo_Tunnel
    destroy loo_TunnelB
    destroy loo_Dt
    return
end if

destroy loo_Channel

// Stop the background listen/accept thread:
li_WaitForThreadExit = 1
li_Success = loo_Tunnel.StopAccepting(li_WaitForThreadExit)
if li_Success <> 1 then
    Write-Debug loo_Tunnel.LastErrorText
    destroy loo_Tunnel
    destroy loo_TunnelB
    destroy loo_Dt
    return
end if

// Close the SSH tunnel (would also kick any remaining connected clients).
li_Success = loo_Tunnel.CloseTunnel(li_WaitForThreadExit)
if li_Success <> 1 then
    Write-Debug loo_Tunnel.LastErrorText
    destroy loo_Tunnel
    destroy loo_TunnelB
    destroy loo_Dt
    return
end if



destroy loo_Tunnel
destroy loo_TunnelB
destroy loo_Dt