I need to pass a NetworkCredential object with the credentials of the currently impersonated user to a web service from an asp.net application. My code look
NetworkCredential
A somewhat lengthy article in MSDN explaining the options to obtain network credentials in ASP:
How To: Use Impersonation and Delegation in ASP.NET 2.0
Another blog article on the topic (though I didn't check whether the solution actually works:
.NET (C#) Impersonation with Network Credentials