We Keep Coding

Avoid UAC prompts when calling another process using C#

I'm developing an iventory software for my company that demands administrative rights (WMI calls, registry access, etc.). For convenience I do no want the UAC to prompt the user for clearance to execute the app (yes, I must force the app to run even if the the user doesn't want), and I can't disable the UAC via GPO (would be perfect but a pain in the ass). I first tried to pass an AD administrative account credentials to the inventory software using another process (Processinfo on C#) but the UAC prompts remained. After a few research I discovered that if use the local Administrator credential it wouldn't give me any annoying prompt but since my company's environment is a mess, there are many stations with different credentials other than the standardized. Does anyone have any idea of how I could do this? (Using .net C#).

I have accomplished this using the Task Scheduler Managed Wrapper. Be sure that you provide the local administrator group credential in setting up the task. Here's how I do it in my code:
using (TaskService ts = new TaskService())
{
try
{
//Create a new task definition and assign properties
TaskDefinition td = ts.NewTask();
td.Principal.RunLevel = TaskRunLevel.Highest;
td.RegistrationInfo.Description = "Paulos Task";
td.Triggers.Add(new TimeTrigger() { StartBoundary = Convert.ToDateTime("01-01-2003 00:00:01") });
// Create an action that will launch PauloApp whenever the trigger fires
td.Actions.Add(new ExecAction("PauloApp.exe", "", Environment.ExpandEnvironmentVariables(#"%ProgramFiles%\Paulo")));
td.Settings.DisallowStartIfOnBatteries = false;
td.Settings.StopIfGoingOnBatteries = false;
ts.RootFolder.RegisterTaskDefinition("PaulosTask", td,
TaskCreation.CreateOrUpdate, "Administrators", null,
TaskLogonType.Group);
// Register the task in the root folder
Microsoft.Win32.TaskScheduler.Task t = ts.FindTask("PaulosTask");
if (t != null)
t.Run();
else
//could not find PaulosTask
}//end try
catch (Exception e)
{
}
}//end using

How to give IIS AppPool Desktop Rights

The action I need help about, is to execute a EXE file on own servers disk from a intranet-webpage, which IIS are on same server-installation. The webpage use a business layer to execute a ProcessStart together with given parameters.
When I perform the execution from web, the taskmanager show me that the application are starting up with the IIS AppPool of webpage as user. Few seconds later it's killed. In my database logs, I can see;
The Microsoft Jet database engine cannot open the file '\\computer\pathfile.ext'. It is already opened exclusively by another user, or you need permission to view its data.
That's correct. The EXE tool are, in turn, loading files from other computers. This is a special behavior which are well studied and well working while using the tool from desktop.
My goal/question,
I want this web-function-call behave with desktop rights. Is it possible at all?
The IIS AppPool have a regular setup with account ApplicationPoolIdentity. I appeared to be "lucky unwise", without knowledge about how much IIS 7.5 and Windows Server 2008 R2 raised the security model since <=IIS6.
I tried to change the app-pool user to NetworkService, Administrator.
I tried to set the application with app-pool as exec/read right
I even tried to let webapp to run a batch-file with a call to application inside..
Then I was begin to change the ProcessStart-behavior. And here, I
don't know much of what to do. I tried to add VERB runas. Force a
password prompt is not a solution here. I tried to simulate a
username/password. No luck there. I also tried to add runas /user:
blabla as parameters with ProcessStart, after used /savecred in a
desktop command window once. No luck there.
Maybe this should work but I just don't understand the correct setup of properties. I add the ProcessStart code snippet below, also added some commented code to let you see what I tried.
public string RunProcess(ApplicationType type, int param)
{
currentSelection = GetApplicationType(type);
ProcessStartInfo info = new ProcessStartInfo(currentSelection.Path);
info.CreateNoWindow = false;
info.UseShellExecute = true;
//info.UseShellExecute = false;
//info.ErrorDialog = false;
//info.UserName = "dummyUsEr";
//info.Password = this.SecurePwd("DummyPWd");
info.WindowStyle = ProcessWindowStyle.Normal;
info.Arguments = string.Format(" {0}", param.ToString());
using (Process exec = Process.Start(info))
{
try
{
exec.WaitForExit();
}
catch
{
}
}
return output;
}
EDIT
Just to be clear, and perhaps help some another guy/girl browsing to this question, I attach the snippet of Password-generation,
protected System.Security.SecureString SecurePwd(string pwd)
{
SecureString securePwd = new SecureString();
foreach (char ch in pwd.ToCharArray())
securePwd.AppendChar(ch);
return securePwd;
}

I see that you've tried putting in a specific username and password for the process start impersonation, but you say that the process accesses files on another computer and I don't see any mention of specifying a domain name which presumably you would need to access remote files?
So like this:
info.Domain = "domainname";
info.UserName = "dummyUsEr";
info.Password = "DummyPWd";
Also, what does this.SecurePwd() do and have you tried it with just the straight password string that you're passing into it?

Changing how a service is configured

When installing a service, there is a helpful .NET class called ServiceProcessInstaller. This class has a property Account, which is a ServiceAccount enumeration with possible values LocalService, LocalSystem, NetworkService and User.
This is fine at install-time, but does anybody know how I can change this value for an existing service?
I assuming that I need to move away from the actual install-type classes, and have been researching hooking into the advapi32 ChangeServiceConfig method, WMI and ManagementObjects etc.
Indeed I have found code which will actually change the account under which the service runs,
ManagementObject mo = new ManagementObject("Win32_Service.Name='" + myService + "'");
object[] configParams = new object[11];
configParams[6] = userName;
configParams[7] = password;
object result = mo.InvokeMethod("Change", configParams);
(which on its own looks a bit like black magic but makes sense when viewed with the ChangeServiceConfig signature)
However when I apply this code to a service which happens to be installed as LocalSystem, it has no effect (although when I interpret result the call is reporting success). This doesn't really surprise me since I am only setting a username and password, I am not saying "rather than running as a local service, this service needs to run under a specific user account".
Now, my gut feel is that I am heading along the right lines here. The problem is that none of the parameters in ChangeServiceConfig appear to offer the opportunity to do this.
Any ideas? TIA, Pete

Error code 16 means "Service marked for deletion". Sometimes when you change service parameter, in particular when you delete / re-create a service you need to reboot your PC for operation to complete. While it's still pending, you can't manipulate service and you get error code 16.
Also, it might not be the case, that you problem has something to do with the fact that the call is inside a dll. If you put you code in a test rig dll and call it from a test rig exe (the same way you tested it in a test rig exe) and don't create / delete service in between I think it will work anyway.
The reason it does not working in your application on my opinion has to do with what you did with the service before (and this something most likely is not described in your question).

You need Impersonate an thread to run at context of user.
Try this class :
A small C# Class for impersonating a User
or this one :
Impersonate User

Return code is 21: "Invalid Parameter".
I ran into the same issue: Problem occurs when trying to apply a new user/password to a service which currently has "LocalSystem" with "Allow Service to interact with desktop" enabled.
To resolve, set the "DesktopInteract" flag in the "Change" query
var query = new ManagementPath(string.Format("Win32_Service.Name='{0}'", serviceName)); // string.Format("SELECT * FROM Win32_Service where Name='{0}'", serviceName);
using (ManagementObject service = new ManagementObject(query))
{
object[] wmiParams = new object[10];
//WMI update doesn't work if the service's user is currently set to LocalSystem
// with Interact with desktop on
wmiParams[5] = false;
wmiParams[6] = serviceUserName;
wmiParams[7] = password;
//update credentials for the service
var rtn = service.InvokeMethod("Change", wmiParams);
}

Getting the current logged in user (FullToken Context)

I have a Problem, which is... i start a programm with right click -> run as administrator.
Which means the programm is running in an administrative context.
WindowsIdentity.GetCurrent().Name;
if i try to get the user name that way i will get the user that started the programm as admin.. for example "administrator", but what i need is the name of the current logged in user which is for example: bob
Can anybody help me out? :)

You could try using WMI (System.Management.dll) to get the owner of the explorer.exe process.
string GetExplorerUser()
{
var query = new ObjectQuery(
"SELECT * FROM Win32_Process WHERE Name = 'explorer.exe'");
var explorerProcesses = new ManagementObjectSearcher(query).Get();
foreach (ManagementObject mo in explorerProcesses)
{
string[] ownerInfo = new string[2];
mo.InvokeMethod("GetOwner", (object[])ownerInfo);
return String.Concat(ownerInfo[1], #"\", ownerInfo[0]);
}
return string.Empty;
}
This relies on the fact that the explorer process is single instance an so you don't end up with the possibility of having several explorer processes running with different user credentials.

You will probably need to use win32 API for that. Read about Window Station and Desktop functions here: http://msdn.microsoft.com/en-us/library/ms687107%28v=vs.85%29.aspx
Also see this question:
Get the logged in Windows user name associated with a desktop

Maybe you could start as normal user, save user name, then programmatically request elevation :
Windows 7 and Vista UAC - Programmatically requesting elevation in C#

All .NET libraries will give you the user from the current context ('Administrator' in your case).
If you are trying to secure your code, you might consider reading about: Security in the .NET framework

1) Cassia should be able to give you a list of currently logged in users including RDC.
foreach (ITerminalServicesSession sess in new TerminalServicesManager().GetSessions())
{
// sess.SessionId
// sess.UserName
}
2) WMI (SO answer)
Select * from Win32_LogonSession
3) PInvoke to WTSEnumerateSessions
4) Enumerate all instances of "explorer.exe" and get the owner using PInvoke (OpenProcessHandle).
Process[] processes = Process.GetProcessesByName("explorer");
This is a bit hacky. WMI can also be used for this.
It might be a good idea to set winmgmt as a dependency for your service if you decided to go with solution that uses WMI.

How to set "interact with desktop" in windows service installer

I have a windows service which runs under system account and executes some programs from time to time (yeah,yeah, I know that's a bad practice, but that's not my decision). I need to set the "interact with desktop" check, to see the gui of that executed programs, after the service is installed. I've tried several ways, putting the code below in AfterInstall or OnCommited event handlers of my service installer:
ConnectionOptions coOptions = new ConnectionOptions();
coOptions.Impersonation = ImpersonationLevel.Impersonate;
ManagementScope mgmtScope = new System.Management.ManagementScope(#"root\CIMV2", coOptions);
mgmtScope.Connect();
ManagementObject wmiService = new ManagementObject("Win32_Service.Name='" + ServiceMonitorInstaller.ServiceName + "'");
ManagementBaseObject InParam = wmiService.GetMethodParameters("Change");
InParam["DesktopInteract"] = true;
ManagementBaseObject OutParam = wmiService.InvokeMethod("Change", InParam, null);
or
RegistryKey ckey = Registry.LocalMachine.OpenSubKey(
#"SYSTEM\CurrentControlSet\Services\WindowsService1", true);
if(ckey != null)
{
if(ckey.GetValue("Type") != null)
{
ckey.SetValue("Type", ((int)ckey.GetValue("Type") | 256));
}
}
both of these methods "work". They set the check, but after I start the service it launches the exe - and gui isn't shown! So, if I stop the service, recheck and start it again - bingo! everything starts and is shown. The second way to achieve the result is to reboot - after it the gui is also shown.
So the question is: Is there a correct way to set "interact with desktop" check, so it'll start working without rechecks and reboots?
OS: Windows XP (haven't tried Vista and 7 yet...)

private static void SetInterActWithDeskTop()
{
var service = new System.Management.ManagementObject(
String.Format("WIN32_Service.Name='{0}'", "YourServiceName"));
try
{
var paramList = new object[11];
paramList[5] = true;
service.InvokeMethod("Change", paramList);
}
finally
{
service.Dispose();
}
}

And finally after searching the internet for a week - I've found a great working solution:
http://asprosys.blogspot.com/2009/03/allow-service-to-interact-with-desktop.html
Find the desktop to launch into. This
may seem facetious but it isn't as
simple as it seems. With Terminal
Services and Fast User Switching there
can be multiple interactive users
logged on to the computer at the same
time. If you want the user that is
currently sitting at the physical
console then you're in luck, the
Terminal Services API call
WTSGetActiveConsoleSessionId will get
you the session ID you need. If your
needs are more complex (i.e. you need
to interact with a specific user on a
TS server or you need the name of the
window station in a non-interactive
session) you'll need to enumerate the
Terminal Server sessions with
WTSEnumerateSessions and check the
session for the information you need
with WTSGetSessionInformation.
Now you know what session you need to
interact with and you have its ID.
This is the key to the whole process,
using WTSQueryUserToken and the
session ID you can now retrieve the
token of the user logged on to the
target session. This completely
mitigates the security problem of the
'interact with the desktop' setting,
the launched process will not be
running with the LOCAL SYSTEM
credentials but with the same
credentials as the user that is
already logged on to that session! No
privilege elevation.
Using CreateProcessAsUser and the
token we have retrieved we can launch
the process in the normal way and it
will run in the target session with
the target user's credentials. There
are a couple of caveats, both
lpCurrentDirectory and lpEnvironment
must point to valid values - the
normal default resolution methods for
these parameters don't work for
cross-session launching. You can use
CreateEnvironmentBlock to create a
default environment block for the
target user.
There is source code of the working project attached.

Same as Heisa but with WMI. (code is Powershell, but can be easily ported to C#)
if ($svc = gwmi win32_service|?{$_.name -eq $svcname})
{
try {
$null = $svc.change($svc.displayname,$svc.pathname,16,1,`
"Manual",$false,$svc.startname,$null,$null,$null,$null)
write-host "Change made"
catch { throw "Error: $_" }
} else
{ throw "Service $svcname not installed" }
See MSDN: Service Change() method for param description.