HTTP Basic Authentication in iOS

HTTPBasicAuthenticationSessionTaskDelegate.swift

/*

Everyone on Stack Overflow does HTTP Basic Authentication on iOS by manually 
building the HTTP headers.

This amounts to re-implementing HTTP.

Why? The Cocoa Touch URL Loading System aleady knows HTTP, and you can
configure your URLSession to supply HTTP Basic Authentication credentials
like so.

Be warned: this example configures the session to use the given credentials on all 
requests, which is probably not what you want.

A better and more authoritative answer from Quinn: https://forums.developer.apple.com/thread/68809

*/

class HTTPBasicAuthenticationSessionTaskDelegate : NSObject, URLSessionTaskDelegate {
  let credential:URLCredential
  init(user:String,password:String) {
    self.credential = URLCredential(user: user, password: password, persistence: URLCredential.Persistence.forSession)
  }

  func urlSession(_ session: URLSession,
                  task: URLSessionTask,
                  didReceive challenge: URLAuthenticationChallenge,
                  completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
    completionHandler(.useCredential,credential)
  }
}

let delegate = HTTPBasicAuthenticationSessionTaskDelegate(user:username,password:password)
let session = URLSession(configuration: URLSessionConfiguration.default, delegate: delegate, delegateQueue: nil)