unit MainUnit;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, OleServer, MSTSCLib_TLB, OleCtrls, Registry;

type
  TFrm = class(TForm)
    RDP: TMsRdpClient2;
    procedure RDPDisconnected(ASender: TObject; discReason: Integer);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Frm: TFrm;
  SecurityLayer, UserAuthentication: DWORD;

implementation

{$R *.dfm}

procedure TFrm.FormCreate(Sender: TObject);
var
  Reg: TRegistry;
  Port: Integer;
begin
  RDP.DisconnectedText := 'Disconnected.';
  RDP.ConnectingText := 'Connecting...';
  RDP.ConnectedStatusText := 'Connected.';
  RDP.UserName := '';
  RDP.Server := '127.0.0.1';
  Reg := TRegistry.Create;
  Reg.RootKey := HKEY_LOCAL_MACHINE;

  if Reg.OpenKey('\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp', True) then
  begin
    try
      SecurityLayer := Reg.ReadInteger('SecurityLayer');
      UserAuthentication := Reg.ReadInteger('UserAuthentication');
      Reg.WriteInteger('SecurityLayer', 0);
      Reg.WriteInteger('UserAuthentication', 0);
    except

    end;
    Reg.CloseKey;
  end;

  if Reg.OpenKeyReadOnly('\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp') then begin
    try
      RDP.AdvancedSettings2.RDPPort := Reg.ReadInteger('PortNumber');
    except

    end;
    Reg.CloseKey;
  end;
  Reg.Free;
  Sleep(1000);
  RDP.Connect;
end;

procedure TFrm.RDPDisconnected(ASender: TObject; discReason: Integer);
var
  ErrStr: String;
  Reg: TRegistry;
begin
  case discReason of
    1: ErrStr := 'Local disconnection.';
    2: ErrStr := 'Disconnected by user.';
    3: ErrStr := 'Disconnected by server.';
    $904: ErrStr := 'Socket closed.';
    $C08: ErrStr := 'Decompress error.';
    $108: ErrStr := 'Connection timed out.';
    $C06: ErrStr := 'Decryption error.';
    $104: ErrStr := 'DNS name lookup failure.';
    $508: ErrStr := 'DNS lookup failed.';
    $B06: ErrStr := 'Encryption error.';
    $604: ErrStr := 'Windows Sockets gethostbyname() call failed.';
    $208: ErrStr := 'Host not found error.';
    $408: ErrStr := 'Internal error.';
    $906: ErrStr := 'Internal security error.';
    $A06: ErrStr := 'Internal security error.';
    $506: ErrStr := 'The encryption method specified is not valid.';
    $804: ErrStr := 'Bad IP address specified.';
    $606: ErrStr := 'Server security data is not valid.';
    $406: ErrStr := 'Security data is not valid.';
    $308: ErrStr := 'The IP address specified is not valid.';
    $808: ErrStr := 'License negotiation failed.';
    $908: ErrStr := 'Licensing time-out.';
    $106: ErrStr := 'Out of memory.';
    $206: ErrStr := 'Out of memory.';
    $306: ErrStr := 'Out of memory.';
    $706: ErrStr := 'Failed to unpack server certificate.';
    $204: ErrStr := 'Socket connection failed.';
    $404: ErrStr := 'Windows Sockets recv() call failed.';
    $704: ErrStr := 'Time-out occurred.';
    $608: ErrStr := 'Internal timer error.';
    $304: ErrStr := 'Windows Sockets send() call failed.';
    $B07: ErrStr := 'The account is disabled.';
    $E07: ErrStr := 'The account is expired.';
    $D07: ErrStr := 'The account is locked out.';
    $C07: ErrStr := 'The account is restricted.';
    $1B07: ErrStr := 'The received certificate is expired.';
    $1607: ErrStr := 'The policy does not support delegation of credentials to the target server.';
    $2107: ErrStr := 'The server authentication policy does not allow connection requests using saved credentials. The user must enter new credentials.';
    $807: ErrStr := 'Login failed.';
    $1807: ErrStr := 'No authority could be contacted for authentication. The domain name of the authenticating party could be wrong, the domain could be unreachable, or there might have been a trust relationship failure.';
    $A07: ErrStr := 'The specified user has no account.';
    $F07: ErrStr := 'The password is expired.';
    $1207: ErrStr := 'The user password must be changed before logging on for the first time.';
    $1707: ErrStr := 'Delegation of credentials to the target server is not allowed unless mutual authentication has been achieved.';
    $2207: ErrStr := 'The smart card is blocked.';
    $1C07: ErrStr := 'An incorrect PIN was presented to the smart card.';
    $B09: ErrStr := 'Network Level Authentication is required.';
    $708: ErrStr := 'The RDP seems to work, but your client doesn''t support loopback connections. Try to connect to your PC from another device in the network.';
    else ErrStr := 'Unknown code 0x'+IntToHex(discReason, 1);
  end;
  if (discReason > 2) then
    MessageBox(Handle, PWideChar(ErrStr), 'Disconnected', mb_Ok or mb_IconError);

  Reg := TRegistry.Create;
  Reg.RootKey := HKEY_LOCAL_MACHINE;

  if Reg.OpenKey('\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp', True) then
  begin
    try
      Reg.WriteInteger('SecurityLayer', SecurityLayer);
      Reg.WriteInteger('UserAuthentication', UserAuthentication);
    except

    end;
    Reg.CloseKey;
  end;

  Reg.Free;

  Halt(0);
end;

end.