The sender of the challenge.
- iOS 2.0+
- macOS 10.2+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
If you are using the
NSURLSession API, this value is purely informational, because you must respond to authentication challenges in your
NSURLSession implementations, by passing
NSURLSession constants to the provided completion handler blocks.
However, if you are using the legacy
NSURLDownload API, you use this object directly in your authentication handler delegate method. With these APIs, after you finish processing the authentication challenge, you respond by calling methods defined in the
NSURLAuthentication protocol on this sender.