C# Custom Remote Desktop Client using RDP 8.0

Question

I have searched MSDN forum for this, but it seems everyone(i think) suggests to revert to RDP 7.x (uninstall MS Update KB2592687).

I have an custom Remote Desktop client written in C#/WPF,the Remote Desktop ActiveX control is hosted inside a WindowsFormsHost control. The app works well prior to update RDP 8.0 (MS Update KB2592687). If i uninstall the MS update(revert to RDP 7.1), the app works.

My RDP Client is used to connect to Virtualbox VRDP (Virtualbox 4.2.x), no authentication needed(Null). With RDP 8.0 installed, the Windows Remote Desktop Client(mstsc.exe) connects just fine, with much better responsiveness(RDP 8.0 enhancements); but my custom RD Client is unable to connect.

Upon further investigation, my custom RDP Client is not throwing any exceptions or firing the OnConnecting and OnLogonError or most of the other events. What's odd is, it is ONLY firing these two events (in order)

OnAuthenticationWarningDisplayed
OnAuthenticationWarningDismissed

I also tested with RawCap(http://www.netresec.com/?page=RawCap) to see if my custom RDP Client is sending packets to Virtualbox VRDP prior to those events. Surprisingly, it's not even sending packets. (MS RD Client - mstsc.exe works fine.)

So it boils down to these events/method calls on my custom RDP Client, and unfortunately I'm stuck.

(Code is shortened for brevity)

    AxMSTSCLib.AxMsRdpClient8 rdp = new AxMSTSCLib.AxMsRdpClient8();

    rdp.OnAuthenticationWarningDisplayed+=new EventHandler(rdp_OnAuthenticationWarningDisplayed);
    rdp.OnAuthenticationWarningDismissed+=new EventHandler(rdp_OnAuthenticationWarningDismissed);
    rdp.Server = server;
    rdp.AdvancedSettings8.RDPPort = 5050;

//No username/password since Virtualbox RDP authentication is set to *null*
//MS RD Client connects just fine to Virtualbox RDP without username/password

    try
    { 
       rdp.Connect();
    }
    catch (Exception ex)
    {
    }

putting a breakpoint on OnAuthenticationWarningDisplayed and OnAuthenticationWarningDismissed confirms both events are fired after Connect() method. I suspect the ActiveX control, after the Connect() method is called, is trying to show a dialogbox(??); but i can't seem to figure out.

Has anyone else done some custom client using RDP 8.0? What are the prerequisites to have it working(code).

Many thanks! Would greatly appreciate it.

Postmark

Answer 1

Solved this problem!

Just try to use AxMSTSCLib.AxMsRdpClient8NotSafeForScripting instead of AxMSTSCLib.AxMsRdpClient8

Here's working code (Delphi):

rdp:TMsRdpClient8NotSafeForScripting; // ***Instead of TMsRdpClient8 (!!!)***
...

if rdp.Connected<>0 then rdp.Disconnect;

rdp.Server:='192.168.1.1';
rdp.UserName:='User';
rdp.AdvancedSettings8.ClearTextPassword:='Password';
rdp.AdvancedSettings8.AuthenticationLevel:=2;
rdp.AdvancedSettings8.EnableCredSspSupport:=true;
rdp.AdvancedSettings8.NegotiateSecurityLayer:=false;

rdp.AdvancedSettings8.RelativeMouseMode:=true;
rdp.AdvancedSettings.BitmapPeristence:=1;
rdp.AdvancedSettings.Compress:=1;
rdp.AdvancedSettings8.SmartSizing:=true;
rdp.DesktopHeight:= Screen.Height;
rdp.DesktopWidth:= Screen.Width;
rdp.FullScreen:=true;
rdp.ColorDepth:= 15;

rdp.AdvancedSettings8.RedirectDrives:=false;
rdp.AdvancedSettings8.RedirectPrinters:=false;
rdp.AdvancedSettings8.RedirectClipboard:=true;
rdp.AdvancedSettings8.RedirectSmartCards:=false;

rdp.Connect;

---

P.S. And do not use the following property:

rdp.AdvancedSettings8.AuthenticationServiceClass

Ditzel