private Impersonation(String userName, String domain, String password, LogOnType logonType, BuiltInUser builtinUser)
{
switch (builtinUser)
{
case BuiltInUser.None: if (String.IsNullOrEmpty(userName))
{
return;
}
break;
case BuiltInUser.LocalService: userName = "******"; break;
case BuiltInUser.NetworkService: userName = "******"; break;
case BuiltInUser.LocalSystem: userName = "******"; break;
}
IntPtr userToken = IntPtr.Zero;
IntPtr userTokenDuplication = IntPtr.Zero;
// Logon with user and get token.
bool loggedOn = LogonUser(userName, domain, password,
logonType, LogOnProvider.Default,
out userToken);
if (loggedOn)
{
try
{
// Create a duplication of the usertoken, this is a solution
// for the known bug that is published under KB article Q319615.
if (DuplicateToken(userToken, 2, ref userTokenDuplication))
{
// Create windows identity from the token and impersonate the user.
WindowsIdentity identity = new WindowsIdentity(userTokenDuplication);
_impersonationContext = identity.Impersonate();
}
else
{
// Token duplication failed!
// Use the default ctor overload
// that will use Mashal.GetLastWin32Error();
// to create the exceptions details.
throw new Win32Exception();
}
}
finally
{
// Close usertoken handle duplication when created.
if (!userTokenDuplication.Equals(IntPtr.Zero))
{
// Closes the handle of the user.
CloseHandle(userTokenDuplication);
userTokenDuplication = IntPtr.Zero;
}
// Close usertoken handle when created.
if (!userToken.Equals(IntPtr.Zero))
{
// Closes the handle of the user.
CloseHandle(userToken);
userToken = IntPtr.Zero;
}
}
}
else
{
// Logon failed!
// Use the default ctor overload that
// will use Mashal.GetLastWin32Error();
// to create the exceptions details.
throw new Win32Exception();
}
}
/// <summary>
/// Initializes a new instance of the <see cref="Impersonation"/> class and
/// impersonates as a built in service account.
/// </summary>
/// <param name="builtinUser">The built in user to impersonate - either
/// Local Service or Network Service. These users can only be impersonated
/// by code running as System.</param>
public Impersonation(BuiltInUser builtinUser)
: this(String.Empty, "NT AUTHORITY", String.Empty, LogOnType.Service, builtinUser)
{
}
