Xbase++

FTP through SSH Tunnel

See more FTP Examples

Demonstrates how to FTP through an SSH tunnel.

The Chilkat SSH tunnel object is used to create a portable SSH tunnel w/ dynamic port forwarding on a background thread that the foreground thread can use for establishing connections through an SSH tunnel.

Xbase++

LOCAL nSuccess
LOCAL oTunnel
LOCAL cSshHostname
LOCAL nSshPort
LOCAL oFtp
LOCAL cLocalPath
LOCAL cRemoteFilename
LOCAL nWaitForThreadExit

nSuccess := 0

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

nSuccess := 0

oTunnel := CreateObject("Chilkat.SshTunnel")

cSshHostname := "sftp.example.com"
nSshPort := 22

//  Connect to an SSH server and establish the SSH tunnel:
nSuccess := oTunnel:Connect(cSshHostname, nSshPort)
IF (nSuccess != 1)
    ? 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 != 1)
    ? 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 != 1)
    ? 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 Socket, 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.

//  Let's do an FTP upload through the SSH tunnel.  Both the control and data connections 
//  go through the tunnel.
oFtp := CreateObject("Chilkat.Ftp2")

oFtp:Hostname := "ftp.example.com"
oFtp:Username := "login"
oFtp:Password := "password"

//  Indicate that the FTP2 object is to use our portable SOCKS proxy/SSH tunnel running in our background thread.
oFtp:SocksHostname := "localhost"
oFtp:SocksPort := 1080
oFtp:SocksVersion := 5
oFtp:SocksUsername := "chilkat123"
oFtp:SocksPassword := "password123"

//  Connect to the FTP server
nSuccess := oFtp:ConnectOnly()
IF (nSuccess != 1)
    ? oFtp:LastErrorText
    oTunnel:destroy()
    oFtp:destroy()
    RETURN
ENDIF

//  Authenticate with the FTP server.
nSuccess := oFtp:LoginAfterConnectOnly()
IF (nSuccess != 1)
    ? oFtp:LastErrorText
    oTunnel:destroy()
    oFtp:destroy()
    RETURN
ENDIF

//  Change to the remote directory where the file will be uploaded.
nSuccess := oFtp:ChangeRemoteDir("junk")
IF (nSuccess != 1)
    ? oFtp:LastErrorText
    oTunnel:destroy()
    oFtp:destroy()
    RETURN
ENDIF

//  Upload a file.
cLocalPath := "/temp/hamlet.xml"
cRemoteFilename := "hamlet.xml"

nSuccess := oFtp:PutFile(cLocalPath, cRemoteFilename)
IF (nSuccess != 1)
    ? oFtp:LastErrorText
    oTunnel:destroy()
    oFtp:destroy()
    RETURN
ENDIF

//  This closes the SSH channel within the SSH tunnel,
//  and thus closes the connection with the FTP server.
nSuccess := oFtp:Disconnect()

? "File Uploaded!"

//  Stop the background listen/accept thread:
nWaitForThreadExit := 1
nSuccess := oTunnel:StopAccepting(nWaitForThreadExit)
IF (nSuccess != 1)
    ? oTunnel:LastErrorText
    oTunnel:destroy()
    oFtp:destroy()
    RETURN
ENDIF

//  Close the SSH tunnel (would also kick any remaining connected clients).
nSuccess := oTunnel:CloseTunnel(nWaitForThreadExit)
IF (nSuccess != 1)
    ? oTunnel:LastErrorText
    oTunnel:destroy()
    oFtp:destroy()
    RETURN
ENDIF

oTunnel:destroy()
oFtp:destroy()