Hello,

This is my situation:  I'm trying to impersonate a different user when
creating a process from inside a .NET assembly on SQL Server.  Basically the
flow looks like this:

stored procedure->static C# function in Assembly->Process created in
Asembly->External Application

This works, but the external app fails because the current WindowsIdentity
is NT AUTHORITY/WINDOWS SERVICE. ; it needs to be someone else.

Now, when you are inside a .NET assembly in SQL Server, you have access to
an object called SqlContext, and it contains (among other things) a
WindowsIdentity object that is the login user who called the stored
procedure in the first place.  This is the user I want to impersonate but I
can't seem to get it to work.

In other postings I've read that you can't get this to work with a Process -
apparently the process still inherits the Principal token and but the
Impersonation token - but it DOES work with Threads.  So I thought I'd spawn
a new Thread with the correct identity and launch my process from inside.
To test the Thread idea I used:

ParameterizedThreadStart pts = new
ParameterizedThreadStart(someThreadFunction);
Thread thread = new Thread(pts);

WindowsIdentity contextID = SqlContext.WindowsIdentity;
using (WindowsImpersonationContext wip = contextID.Impersonate())
{
  thread.Start(test);
  while (thread.ThreadState == System.Threading.ThreadState.Running) { }
  wip.Undo();
}

But inside the Thread function (someThreadFunction) the
WindowsIdentity.GetCurrent() still returns NT AUTHORITY/WINDOWS SERVICE.

Am I going about this all wrong?  Is this even possible?

Any advice/suggestions appreciated!

Keith