At my customer the good old problem of needing to run tests as different users came up again. I have tried to solve this before and came up with parts of the login dialogue handler.

The problem is this: when IE starts it uses information in the HKEY Current Users registry hive to decide who it should launch IE as. This prevents using an impersonated user token to start IE.

The other way is to use System.Diagnostics.Process start to start the process (or run as), but then you can’t control IE as it is running as another user.

Well as it turns out, the solution was staring me right in the face all along and the answer is to use BOTH of these methods, not one or the other.

First we need to launch a new IE process using System.Diagnostics.Process start with different user credentials, then we need to use impersonation to fire up watin in a another thread, attatch to IE and we are away. I have included the code which needs a Refactor and tidy up in a big way, but it works.

It won’t work on Vista with IE 7 because of the attatchto bug, but that is fixed in IE8, Also it is also leaving a process behind when the test finishes.

The impersonation code is from this Microsoft blog http://blogs.msdn.com/jimmytr/archive/2007/04/14/writing-test-code-with-impersonation.aspx

Enjoy,

[TestMethod]
    public void TestMethod()
    {
        SecureString password = new SecureString();
        password.AppendChar('p');
        password.AppendChar('a');
        password.AppendChar('s');
        password.AppendChar('s');
        password.AppendChar('w');
        password.AppendChar('o');
        password.AppendChar('r');
        password.AppendChar('d');

        ProcessStartInfo psi = new ProcessStartInfo();
        psi.UserName = "localtest";
        psi.Password = password;
        psi.UseShellExecute = false;
        psi.LoadUserProfile = true;
        psi.FileName = "c:\\Program Files\\Internet Explorer\\iexplore.exe";
        psi.Arguments = "about:blank";

        Process proc = new Process();
        proc.StartInfo = psi;
        proc.Start();

        t.Join();

        proc.Kill();
    }

    private static void DoWorkAs(object o)
    {
        User u = o as User;

        IntPtr hToken = IntPtr.Zero;
        IntPtr hTokenDuplicate = IntPtr.Zero;

        if (Win32.LogonUser(u.UserName, u.Domain, u.Password, 2 /*LOGON32_LOGON_INTERACTIVE*/, 0 /*LOGON32_PROVIDER_DEFAULT*/, out hToken))
        {
            if (Win32.DuplicateToken(hToken, 2, out hTokenDuplicate))
            {
                WindowsIdentity windowsIdentity = new WindowsIdentity(hTokenDuplicate);
                WindowsImpersonationContext impersonationContext = windowsIdentity.Impersonate();

                // domain\username
                Console.WriteLine(" Thread 2 : " + WindowsIdentity.GetCurrent().Name);

                IE ie = IE.AttachToIE(Find.ByUrl("about:blank"));

                ie.GoTo(@"http://www.google.com/");
                ie.TextField(Find.ByName("q")).TypeText("WatiN");
                ie.Button(Find.ByName("btnG")).Click();

                Assert.IsTrue(ie.ContainsText("WatiN"));
                ie.GoTo("about:blank");

                //revert
                impersonationContext.Undo();
                Console.WriteLine(WindowsIdentity.GetCurrent().Name);
            }
        }
        if (hToken != IntPtr.Zero) Win32.CloseHandle(hToken);
        if (hTokenDuplicate != IntPtr.Zero) Win32.CloseHandle(hTokenDuplicate);
    }

    public class User
    {
        public User(string u, string d, string p)
        {
            Domain = d;
            UserName = u;
            Password = p;
        }
        public string UserName;
        public string Domain;
        public string Password;
    }
    public class Win32
    {
        // P/Invoke snask
        [DllImport("advapi32.dll", SetLastError = true)]
        public static extern bool LogonUser(
            string lpszUsername,
            string lpszDomain,
            string lpszPassword,
            int dwLogonType,
            int dwLogonProvider,
            out IntPtr phToken);

        [DllImport("advapi32.dll", SetLastError = true)]
        public extern static bool DuplicateToken(IntPtr ExistingTokenHandle, int
           SECURITY_IMPERSONATION_LEVEL, out IntPtr DuplicateTokenHandle);

        [DllImport("kernel32.dll", SetLastError = true)]
        public static extern bool CloseHandle(IntPtr hHandle);

    }