Pascal (Lazarus/Delphi)

WebSocket Connect through SOCKS Proxy

See more WebSocket Examples

This example shows how to establish a WebSocket connection through a SOCKS proxy. 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.Rest,
  Chilkat.WebSocket,
  Chilkat.Socket;

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

procedure RunDemo;
var
  success: Boolean;
  rest: TRest;
  socket: TSocket;
  bTls: Boolean;
  port: Integer;
  maxWaitMs: Integer;
  ws: TWebSocket;
  responseBody: string;
  statusCode: Integer;

begin
  success := False;

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

  //  --------------------------------------------------
  //  This example borrows the code from the REST using SOCKS Proxy example.
  //  We first use the Chilkat Socket object to establish a connection to the WebSocket server through a SOCKS proxy.
  //  Next, the Rest object uses the Socket object for its connection.
  //  Finally, the WebSocket object uses the Rest object for its connection.  
  //  

  rest := TRest.Create;
  socket := TSocket.Create;

  //  Set the SOCKS proxy domain or IP address, port, and SOCKS version number (4 or 5)
  socket.SocksHostname := '192.168.1.79';
  socket.HttpProxyPort := 1080;
  socket.SocksVersion := 5;

  //  Provide authentication to the SOCKS proxy, if needed.
  socket.SocksUsername := 'SOCKS_PROXY_LOGIN';
  socket.SocksPassword := 'SOCKS_PROXY_PASSWORD';

  //  Connect to the websocket server through the HTTP proxy.
  bTls := False;
  port := 80;
  maxWaitMs := 5000;
  success := socket.Connect('some-websocket-server.com',port,bTls,maxWaitMs);
  if (success <> True) then
    begin
      WriteLn('Connect Failure Error Code: ' + socket.ConnectFailReason);
      WriteLn(socket.LastErrorText);
      Exit;
    end;

  //  Tell the Rest object to use the connected socket.
  success := rest.UseConnection(socket,True);
  if (success <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  ws := TWebSocket.Create;

  //  Tell the WebSocket to use this connection.
  success := ws.UseConnection(rest);
  if (success <> True) then
    begin
      WriteLn(ws.LastErrorText);
      Exit;
    end;

  //  Add the standard WebSocket open handshake headers that will be needed.
  //  (This adds the required HTTP request headers to the rest object.)
  ws.AddClientHeaders();

  //  Add any additional headers that might be desired.
  //  Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
  rest.AddHeader('Sec-WebSocket-Protocol','x-some-websocket-subprotocol');
  rest.AddHeader('Origin','http://some-websocket-server.com');

  //  Do the open handshake.
  responseBody := rest.FullRequestNoBody('GET','/something');
  if (rest.LastMethodSuccess <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  //  If successful, the HTTP response status code should be 101,
  //  and the response body will be empty. (If it failed, we'll have a look
  //  at the response body..)
  statusCode := rest.ResponseStatusCode;
  WriteLn('Response status code: ' + statusCode);

  if (statusCode <> 101) then
    begin
      WriteLn(responseBody);
      WriteLn('-- Failed because of unexpected response status code.');
      Exit;
    end;

  //  We have the expected 101 response, so let's now validate the 
  //  contents of the response, such as the value sent by the server in the
  //  Sec-WebSocket-Accept header. 
  success := ws.ValidateServerHandshake();
  if (success <> True) then
    begin
      WriteLn(ws.LastErrorText);
      Exit;
    end;

  WriteLn('WebSocket connection successful.');

  //  The application may now begin sending and receiving frames on the WebSocket connection.
  //  (At this point, we're done with the rest and socket objects...)

  WriteLn('Success.');


  rest.Free;
  socket.Free;
  ws.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.