Pascal (Lazarus/Delphi)

SSH Tunnel (Port Forwarding via direct-tcpip channel)

See more SSH Examples

Demonstrates how to create an SSH tunnel to a remote hostname:port via a direct-tcpip channel. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.Ssh;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  ssh: TSsh;
  hostname: string;
  port: Integer;
  channelNum: Integer;
  httpReq: string;
  caseSensitive: Boolean;
  matchStr: string;
  responseHeader: string;
  numBytesRead: Integer;
  pollTimeoutMs: Integer;
  htmlBody: string;

begin
  success := False;

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

  ssh := TSsh.Create;

  //  Connect to an SSH server:

  //  Hostname may be an IP address or hostname:
  hostname := '192.168.1.117';
  port := 22;

  success := ssh.Connect(hostname,port);
  if (success <> True) then
    begin
      WriteLn(ssh.LastErrorText);
      Exit;
    end;

  //  Wait a max of 5 seconds when reading responses..
  ssh.IdleTimeoutMs := 5000;

  //  Authenticate using login/password:
  success := ssh.AuthenticatePw('chilkat','myPassword');
  if (success <> True) then
    begin
      WriteLn(ssh.LastErrorText);
      Exit;
    end;

  //  Open a direct-tcpip channel.  We want the SSH server to connect
  //  to www.chilkatsoft.com, port 80 (i.e. the web server).
  //  Data sent through the SSH tunnel is forwarded to the remote
  //  host:port.  (Note: The remote host:port does not need to be 
  //  a web server.  It can be anything.  It can be your own
  //  customer application server that listens on a port, or any
  //  other type of server.)
  //  When we read from the SSH channel, we'll be reading data
  //  sent from the remote host:port (i.e. the web server in this
  //  example).

  channelNum := ssh.OpenDirectTcpIpChannel('www.chilkatsoft.com',80);
  if (channelNum < 0) then
    begin
      WriteLn(ssh.LastErrorText);
      Exit;
    end;

  //  Build a simple HTTP GET request for http://www.chilkatsoft.com/xyz.html
  httpReq := 'GET /xyz123.html HTTP/1.1' + #13#10 + 'Host: www.chilkatsoft.com' + #13#10 + #13#10;

  //  Send the HTTP request:
  success := ssh.ChannelSendString(channelNum,httpReq,'ansi');
  if (success <> True) then
    begin
      WriteLn(ssh.LastErrorText);
      Exit;
    end;

  //  Get the HTTP response.
  //  First read the HTTP response header which ends with a double CRLF.
  //  Calling ChannelReceiveUntilMatch will receive until match string is seen,
  //  or until a timeout occurs (IdleTimeoutMs property).  ChannelReceiveUntilMatch
  //  may read beyond the match string, but it will stop reading as soon as the match
  //  string is seen.
  caseSensitive := False;
  matchStr := #13#10 + #13#10;
  success := ssh.ChannelReceiveUntilMatch(channelNum,matchStr,'ansi',caseSensitive);
  if (success <> True) then
    begin
      WriteLn(ssh.LastErrorText);
      Exit;
    end;

  //  Extract the HTTP header from the receive buffer.
  //  (GetReceiveTextS extracts up to and including the match string from the receive buffer)

  responseHeader := ssh.GetReceivedTextS(channelNum,matchStr,'ansi');
  WriteLn('---- HTTP Response Header ----');
  WriteLn(responseHeader);

  //  Now get the body of the HTTP response (this is the HTML content
  //  of http://www.chilkatsoft.com/xyz.html
  //  It's possible we've already received the entire HTTP response in the
  //  call to ChannelReceiveUntilMatch.  Therefore, we'll poll for any remaining data
  //  and wait a max of .2 seconds.

  pollTimeoutMs := 200;
  numBytesRead := ssh.ChannelPoll(channelNum,pollTimeoutMs);
  //  We're not checking for an error here.
  //  A return value of -2 means that no data was available and the poll simply timed out (not an error)
  //  A return value of -1 indicates an error.
  //  A return value greater than 0 indicates that additional data was received.

  WriteLn('---- HTML BODY ----');

  //  Extract the remainder of the accumulated data in the internal receive buffer.
  //  This should be our HTML body:

  htmlBody := ssh.GetReceivedText(channelNum,'ansi');
  WriteLn(htmlBody);

  //  Close the channel:
  success := ssh.ChannelSendClose(channelNum);
  if (success <> True) then
    begin
      WriteLn(ssh.LastErrorText);
      Exit;
    end;

  //  Disconnect
  ssh.Disconnect();


  ssh.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.