HttpWebRequest with basic authentication fails with 401 error for DefaultNetworkCredentials

问题

I am testing an application with a local Web server (IIS, Windows 8), the site requires Basic authentication, and as long as I explicitly pass my credentials, everything works fine:

request.Credentials = new NetworkCredential("User", "Password", "Domain");
request.PreAuthenticate = true;

But I would like to use integrated security, so I tried to change the first line as follows:

request.Credentials = CredentialCache.DefaultNetworkCredentials;

(I also tried DefaultCredentials)

I checked the network traffic with Fiddler, and I see that in the second case Http request is sent without an authorization header, so it's not surprising that it fails. But why?

UPDATE. I believe I misunderstood default credentials concept. DefaultNetworkCredentials may not be used to generate basic authentication header, it must be a user/password pair. So this behavior is by design.

回答1:

Thanks to people who commented on the topic, I realized that I misunderstood the concept of default credentials. They can't be used in the case then only Basic authentication is enabled, so this is the correct behavior.

来源：https://stackoverflow.com/questions/14402869/httpwebrequest-with-basic-authentication-fails-with-401-error-for-defaultnetwork