Pascal (Lazarus/Delphi)

Upgrade an FTP Control Channel to TLS (ConvertToTls)

Demonstrates the Chilkat Ftp2.ConvertToTls method, which upgrades an already-connected clear FTP control channel to explicit TLS. It takes no arguments and is used with a manually staged connection created by ConnectOnly while Ssl is disabled.

Background: This exposes the explicit-FTPS AUTH TLS upgrade as a discrete step for the rare case where you need to do something on the clear connection first — inspect the greeting, apply a workaround — before securing it. In the normal case you simply set AuthTls and let Connect perform the upgrade automatically; this manual path exists for staged control.

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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.Ftp2;

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

procedure RunDemo;
var
  success: Boolean;
  ftp: TFtp2;

begin
  success := False;

  //  Demonstrates the Ftp2.ConvertToTls method, which upgrades an already-connected clear FTP control
  //  channel to explicit TLS.  It takes no arguments.  It is used with a manually staged connection
  //  created by ConnectOnly while Ssl is disabled.

  ftp := TFtp2.Create;

  ftp.Hostname := 'ftp.example.com';
  ftp.Port := 21;

  //  Connect in clear text first (Ssl is false).
  success := ftp.ConnectOnly();
  if (success = False) then
    begin
      WriteLn(ftp.LastErrorText);
      Exit;
    end;

  //  Upgrade the control channel to explicit TLS (AUTH TLS).
  success := ftp.ConvertToTls();
  if (success = False) then
    begin
      WriteLn(ftp.LastErrorText);
      Exit;
    end;

  //  Now authenticate over the encrypted control channel.
  ftp.Username := 'myFtpLogin';
  ftp.Password := 'myPassword';
  success := ftp.LoginAfterConnectOnly();
  if (success = False) then
    begin
      WriteLn(ftp.LastErrorText);
      Exit;
    end;
  WriteLn('Control channel upgraded to TLS and logged in.');

  success := ftp.Disconnect();
  if (success = False) then
    begin
      WriteLn(ftp.LastErrorText);
      Exit;
    end;


  ftp.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.