I have a .NET MVC3 application that needs to be able to turn a remote service on and off. In order to do this I am impersonating a specific user account via WindowsIdentity.Impersonate(). To test the user's permissions I can log in as the user and execute sc.exe \\[server] start [service]
from the command prompt. I also know that the impersonate command is working as expected because the application runs anonymously and therefore cannot control services on my local machine (.
) without impersonation, but can control local services with impersonation. However, when I put it together and attempt to start the remote service rather than local service I always get the error "Cannot open [service]
service on computer '[server]
'"
Has anyone ever experienced a similar issue? I was expecting it to be a server configuration rather than .NET issue until I realized that sc.exe works without issue. Here is an abbreviated version of the class that I am using:
public class Service
{
public string Name;
public bool Running;
private ServiceController serviceController;
public Service(string name, string host)
{
Name = name;
serviceController = new ServiceController(Name, host);
Running = serviceController.Status == ServiceControllerStatus.Running;
}
public bool StartService()
{
ServiceControllerPermission scp = new ServiceControllerPermission(ServiceControllerPermissionAccess.Control, serviceController.MachineName, Name);
scp.Assert();
serviceController.Start();
serviceController.WaitForStatus(ServiceControllerStatus.Running, new TimeSpan(0, 0, 5));
serviceController.Refresh();
Running = serviceController.Status == ServiceControllerStatus.Running;
return Running;
}
}
One additional note: If instead of the server I point the application at another Windows 7 PC on the domain and change the impersonation credentials to those of the owner of that PC, I am actually able to remotely control their services without issue.
Per request, I am adding the impersonation code here. It is a little longer so bear with me:
public class Impersonate
{
public const int LOGON32_LOGON_INTERACTIVE = 2;
public const int LOGON32_PROVIDER_DEFAULT = 0;
WindowsImpersonationContext impersonationContext;
[DllImport("advapi32.dll")]
public static extern int LogonUserA(String lpszUserName,
String lpszDomain,
String lpszPassword,
int dwLogonType,
int dwLogonProvider,
ref IntPtr phToken);
[DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
public static extern int DuplicateToken(IntPtr hToken,
int impersonationLevel,
ref IntPtr hNewToken);
[DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
public static extern bool RevertToSelf();
[DllImport("kernel32.dll", CharSet = CharSet.Auto)]
public static extern bool CloseHandle(IntPtr handle);
public bool impersonateValidUser(String userName, String domain, String password)
{
WindowsIdentity tempWindowsIdentity;
IntPtr token = IntPtr.Zero;
IntPtr tokenDuplicate = IntPtr.Zero;
if (RevertToSelf())
{
if (LogonUserA(userName, domain, password, LOGON32_LOGON_INTERACTIVE,
LOGON32_PROVIDER_DEFAULT, ref token) != 0)
{
if (DuplicateToken(token, 2, ref tokenDuplicate) != 0)
{
tempWindowsIdentity = new WindowsIdentity(tokenDuplicate);
impersonationContext = tempWindowsIdentity.Impersonate();
if (impersonationContext != null)
{
CloseHandle(token);
CloseHandle(tokenDuplicate);
return true;
}
}
}
}
if (token != IntPtr.Zero)
CloseHandle(token);
if (tokenDuplicate != IntPtr.Zero)
CloseHandle(tokenDuplicate);
return false;
}
public void undoImpersonation()
{
impersonationContext.Undo();
}
}
I call this code just before attempting to start or stop the service:
Service s = new Service(ServiceName, MachineName);
if (Impersonation.impersonateValidUser(Username, Domain, Password))
{
if (s.Running)
s.StopService();
else
s.StartService();
Impersonation.undoImpersonation();
}
It may be worth noting that I can list the services and get the status of an individual service (as I do here) just fine - it is only when I go to start or stop the service that I run into trouble.
Well, that was correct if the user you want to impersonate is a machine administrator. If it is not, then you have to give the user the particular rights to start the service.
As I am not a network admin, I didn't know how to make it, but I have found this link that explains how to do it with the subinacl tool:
http://www.waynezim.com/2010/02/how-to-set-permission-on-a-service-using-subinacl/
To download
And finally, the command line would be:
Users=TO grants start/stop permissions to the user
In this case you have to impersonate the user with the INTERACTIVE mode and not with the SERVICE mode
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