C#

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.

C#

bool success = false;

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

success = false;

Chilkat.SshTunnel tunnel = new Chilkat.SshTunnel();

string sshHostname = "sftp.example.com";
int sshPort = 22;

// Connect to an SSH server and establish the SSH tunnel:
success = tunnel.Connect(sshHostname,sshPort);
if (success != true) {
    Debug.WriteLine(tunnel.LastErrorText);
    return;
}

// Authenticate with the SSH server via a login/password
// or with a public key.  
// This example demonstrates SSH password authentication.
success = tunnel.AuthenticatePw("mySshLogin","mySshPassword");
if (success != true) {
    Debug.WriteLine(tunnel.LastErrorText);
    return;
}

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

// 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.

tunnel.InboundSocksUsername = "chilkat123";
tunnel.InboundSocksPassword = "password123";

// Start the listen/accept thread to begin accepting SOCKS proxy client connections.
// Listen on port 1080.
success = tunnel.BeginAccepting(1080);
if (success != true) {
    Debug.WriteLine(tunnel.LastErrorText);
    return;
}

// 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.
Chilkat.Ftp2 ftp = new Chilkat.Ftp2();

ftp.Hostname = "ftp.example.com";
ftp.Username = "login";
ftp.Password = "password";

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

// Connect to the FTP server
success = ftp.ConnectOnly();
if (success != true) {
    Debug.WriteLine(ftp.LastErrorText);
    return;
}

// Authenticate with the FTP server.
success = ftp.LoginAfterConnectOnly();
if (success != true) {
    Debug.WriteLine(ftp.LastErrorText);
    return;
}

// Change to the remote directory where the file will be uploaded.
success = ftp.ChangeRemoteDir("junk");
if (success != true) {
    Debug.WriteLine(ftp.LastErrorText);
    return;
}

// Upload a file.
string localPath = "/temp/hamlet.xml";
string remoteFilename = "hamlet.xml";

success = ftp.PutFile(localPath,remoteFilename);
if (success != true) {
    Debug.WriteLine(ftp.LastErrorText);
    return;
}

// This closes the SSH channel within the SSH tunnel,
// and thus closes the connection with the FTP server.
success = ftp.Disconnect();

Debug.WriteLine("File Uploaded!");

// Stop the background listen/accept thread:
bool waitForThreadExit = true;
success = tunnel.StopAccepting(waitForThreadExit);
if (success != true) {
    Debug.WriteLine(tunnel.LastErrorText);
    return;
}

// Close the SSH tunnel (would also kick any remaining connected clients).
success = tunnel.CloseTunnel(waitForThreadExit);
if (success != true) {
    Debug.WriteLine(tunnel.LastErrorText);
    return;
}