Protected frontend GUI

BlitzMax Forums/BlitzMax Programming/Protected frontend GUI

EOF (Posted 2006) [#1]

(EDIT - Maybe this should be in GUI programming??) I am starting a project whereby I want to create a protected frontend GUI which restricts a user from tampering with the Windows installation. For me, its far too easy for a casual user to accidently screw around with the setup. Renaming, deleting, moving icons, deleting stuff from folders, messing up the display, installing spyware freebie stuff, etc.. I really want to crack down hard and set major limitations in place. My idea is to create a protected frontend display much like you see in a Kiosk. Something which still lets the user click icons, open utilities, and the likes but prevents them from tampering with the O/S itself. Basically, a sandboxed system. So, I need to: 1) Stop the user Alt-Tabbing into the O/S 2) Kill all system keys such as Ctrl+Alt,Del, the Windows key, menu key, sticky keys. 3) Kill all popup alerts ("Updates ready", "Virus database out of date") 4) Allow only selected drives/folders to be viewable from applications like Notepad, MSPaint 5) Hide the windows taskbar (if 'Always on top' is selected) Just to give you a taster here is a 'very basic' frontend GUI SuperStrict Framework BRL.Win32MaxGUI AppTitle="ProtectedGUI" Global dt:TGadget=Desktop() Global dtW%=dt.Width Global dtH%=dt.Height Global taskbarH%=52 Global panW%=140 Global time$=CurrentTime$() Global mb% Global win:TGadget=CreateWindow("Test",0,-18,dtW,dtH+18,Desktop(),EVENT_WINDOWACTIVATE) Global displaypanel:TGadget=CreatePanel(0,0,win.Width,win.Height-taskbarH,win,PANEL_ACTIVE) Global taskbarpanel:TGadget=CreatePanel(0,displaypanel.Height,win.Width,taskbarH-18,win,PANEL_ACTIVE) Global btn_Menu:TGadget=CreateButton("Menu",4,4,56,taskbarpanel.Height-8,taskbarpanel) Global taskbarinfo:TGadget=CreatePanel(win.Width-panW-4,4,panW,taskbarpanel.Height-8,taskbarpanel,PANEL_BORDER) Global lbl_Time:TGadget=CreateLabel("",taskbarinfo.Width-38,4,38,taskbarinfo.Height-8,taskbarinfo) SetPanelColor displaypanel,$22,$44,$aa SetGadgetText lbl_Time,time[0..time.Length-3] Global popupmenu:TGadget=CreateMenu(AppTitle,000,Null) CreateMenu("Preferences",101,popupmenu) CreateMenu("",000,popupmenu) CreateMenu("Switch User",102,popupmenu) CreateMenu("Exit",103,popupmenu) Global debugwindow:TGadget=CreateListBox(10,10,400,142,displaypanel) Repeat Local s$ 'Debug CurrentEvent.ToString() Select WaitEvent() Case EVENT_MOUSEMOVE Case EVENT_MOUSEDOWN mb=EventData() If EventSource()=displaypanel s$="Display" If EventSource()=taskbarpanel s$="TaskBar" Debug s$+" > Mouse Button = "+String(mb) Case EVENT_GADGETACTION Select EventSource() Case btn_Menu MoveMouse taskbarpanel.XPos+4 , taskbarpanel.YPos PopupWindowMenu win,popupmenu End Select Case EVENT_MENUACTION Debug "Menu > "+EventData() If EventData()=103 Exit End Select Forever End Function Debug(txt$) If CountGadgetItems(debugwindow)>8 ClearGadgetItems debugwindow If txt$<>"" AddGadgetItem debugwindow,txt$ SelectGadgetItem debugwindow,CountGadgetItems(debugwindow)-1 EndIf End Function My idea is to add a "Admin" mode which allows the complete control of what is accessible to the user, as well as a quit option to return back to Windows. Task too big?

popcade (Posted 2006) [#2]

Didn't do any hook programming on Windows yet... but I heard that's a lot of work.. :|

Azathoth (Posted 2006) [#3]

So is this like a desktop environment?

Fabian. (Posted 2006) [#4]

You could use multiple desktops. Windows creates the most gui stuff on the Default desktop. So if you create another desktop and run your application on this desktop you could have a much more secure system than normal windows. Using a seperate desktop can solve all points in the list you made except number 4. I wrote some code showing how this could work, if the app is started once the user can't switch back to the Default desktop manually. You need to click the application's button to close it and return to windows - however, you can easily change the application's source code to make the button invisible or disabled and then the user can't get back to the OS at all. I just tried out myself - even Ctrl-Alt-Del doesn't help. So here's the code: Strict Rem bbdoc:WinDesktop EndRem 'Module fmc.WinDesktop 'ModuleInfo "Version: 0.06" 'ModuleInfo "Modserver: Fabian" ?Win32 Import brl.linkedlist Import brl.win32maxgui Const LabelText$ = "Be sure that the user has no possibility to switch back the desktop manually; "+.. "only by clicking the button below you can access to the old windows system desktop, however, "+.. "you can easily edit this code and write it without the button." If Len AppArgs = 2 Global Window:TGadget = CreateWindow ( "" , 50 , 50 , 400 , 424 , Desktop ( ) , 0 ) Global Label:TGadget = CreateLabel ( LabelText , 0 , 0 , 400 , 400 , Window ) Global Button:TGadget = CreateButton ( "Switch back, please!" , 0 , 400 , 400 , 24 , Window ) AddHook EmitEventHook , Func Global Ending While Not Ending WaitEvent Wend Function Func:Object ( id , data:Object , context:Object ) Local Event:TEvent = TEvent ( data ) If Event.source = Button And Event.id = EVENT_GADGETACTION SwitchUserDesktop AppArgs [ 1 ] Ending = True EndIf Return data EndFunction Else Local Desk$ = "OurNewDesktop" CreateProcessOnDesktop "~q" + AppFile + "~q Default" , Desk While Not SwitchUserDesktop ( Desk ) Wend EndIf Rem bbdoc:Create a process on a specified desktop returns:#brl.blitz.True if successfully, else #brl.blitz.False EndRem Function CreateProcessOnDesktop ( CmdLine$ , Desk$ ) Local Success Local StartupInfo:TStartupInfo = New TStartupInfo Local ProcessInformation:TProcessInformation = New TProcessInformation StartupInfo.Size = SizeOf TStartupInfo StartupInfo.Desk = Desk.ToWString ( ) Local Cmd:Short Ptr = CmdLine.ToWString ( ) If CreateProcessW ( Null , Cmd , Null , Null , False , 0 , Null , Null , StartupInfo , ProcessInformation ) CloseHandle ProcessInformation.Process CloseHandle ProcessInformation.Thread Success = True EndIf MemFree StartupInfo.Desk MemFree Cmd Return Success EndFunction Rem bbdoc:Change the user's desktop returns:#brl.blitz.True if successfully, else #brl.blitz.False EndRem Function SwitchUserDesktop ( Name$ ) Local Success Local Desk:Short Ptr = Name.ToWString ( ) Local Handle = OpenDesktopW ( Desk , 0 , False , $100 ) If Handle If SwitchDesktop ( Handle ) Success = True EndIf CloseDesktop Handle EndIf MemFree Desk Return Success EndFunction Rem bbdoc:Get the desktop names returns:A string array containing the names of the desktops EndRem Function GetDesktops$ [] ( ) Local List:TList = CreateList ( ) EnumDesktopsW GetProcessWindowStation ( ) , EnumProc , ( Int Ptr Varptr List ) [ 0 ] Local ObjectArray:Object [] = ListToArray ( List ) Local StringArray$ [ Len ObjectArray ] For Local I = 0 Until Len StringArray StringArray [ I ] = String ObjectArray [ I ] Next Return StringArray Function EnumProc ( Desk:Short Ptr , Param:TList ) ListAddLast Param , String.FromWString ( Desk ) Return True EndFunction EndFunction Private Type TProcessInformation Field Process Field Thread Field ProcessId Field ThreadId EndType Type TStartupInfo Field Size Field Reserved0:Short Ptr Field Desk:Short Ptr Field Title:Short Ptr Field X Field Y Field XSize Field YSize Field XCountChars Field YCountChars Field FillAttribute Field Flags Field ShowWindow:Short Field Reserved1:Short Field Reserved2:Byte Ptr Field StdInput Field StdOutput Field StdError EndType Extern "Win32" Function EnumDesktopsW ( WinSta , Func:Byte Ptr , Param ) Function GetProcessWindowStation ( ) Function CreateProcessW ( App:Short Ptr , Cmd:Short Ptr , PA:Byte Ptr , TA:Byte Ptr , IH , CF , Env:Byte Ptr , CD:Short Ptr , SI:Byte Ptr , P:Byte Ptr ) Function CloseHandle ( Obj ) Function OpenDesktopW ( Name:Short Ptr , F , I , DA ) Function CloseDesktop ( Desk ) Function SwitchDesktop ( Desk ) EndExtern ? The functions are extracted from my module, feel free to use them in your applications if you like. I used code like this to create a winlock tool (source here), which can be used to protect the system if you are temorary away and leave the system alone. The application asks you for a password and as soon as you entered it the OS gets locked and you can't do anything if you don't enter the password again. I'm quite sure that the user can't do anything on the secondary desktop; except the actions you explicitly allowed.

EOF (Posted 2006) [#5]

Great work Franz. Thats the sort of thing I'm after. I'll have a play. Many thanks!