Returns the System.Net.NetworkCredential instance associated with the specified host, port, and authentication protocol.
A System.Net.NetworkCredential or, if there is no matching credential in the cache, null.
This method searches the System.Net.CredentialCache and returns the System.Net.NetworkCredential instance for the specified host, port, and authorization type. The host, port, and authType values passed to this method are case-insensitively compared to the values specified when the credential was added to the System.Net.CredentialCache using the erload:System.Net.CredentialCache.Add methods.
The supported values for authType are "NTLM", "Digest", "Kerberos", and "Negotiate".