iOS first app, accept untrusted certificate for hello world - ios

Question

I am making a basic "hello world" iOS app. I have an ubuntu server in the cloud which I want to query from the iOS app. I understand that the server needs to be secure, ie, needs to be accessed via https request, and the certificate on the server needs to be "trusted".
Right now what I am trying to do is override this requirement. I have a self-signed certificate that is working for https on my server. When I make the request with the iOS app, it gives me some errors about NSURLErrorFailingURLPeerTrustErrorKey and even one line returned saying: NSLocalizedRecoverySuggestion=Would you like to connect to the server anyway?.
I know this is a common issue and there are many threads on this site about how to deal with it. I tried a piece of code from this post. I added this piece to my code:
func URLSession(session: NSURLSession, task: NSURLSessionTask, didReceiveChallenge challenge: NSURLAuthenticationChallenge, completionHandler: (NSURLSessionAuthChallengeDisposition, NSURLCredential?) -> Void) {
if challenge.protectionSpace.authenticationMethod == NSURLAuthenticationMethodServerTrust{
let credential = NSURLCredential(forTrust: challenge.protectionSpace.serverTrust!)
completionHandler(NSURLSessionAuthChallengeDisposition.UseCredential,credential);
}
}
My entire ViewController code is here:
import UIKit
class ViewController: UIViewController, UITextFieldDelegate, NSURLSessionDelegate {
// MARK: Properties
#IBOutlet weak var nameTextField: UITextField!
#IBOutlet weak var mealNameLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
// Handle the text field’s user input through delegate callbacks.
nameTextField.delegate = self
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: UITextFieldDelegate
func textFieldShouldReturn(textField: UITextField) -> Bool {
// Hide the keyboard.
textField.resignFirstResponder()
return true
}
func textFieldDidEndEditing(textField: UITextField) {
mealNameLabel.text = nameTextField.text
}
// MARK: Actions
#IBAction func setDefaultLabelText(sender: UIButton) {
mealNameLabel.text = "Default Text"
post_request()
}
func post_request(){
let request = NSMutableURLRequest(URL: NSURL(string: "https://54.164.XXX.XX/post_script.php")!)
request.HTTPMethod = "POST"
let postString = "id=13&name=Jack"
request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding)
let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
data, response, error in
if error != nil {
print("error=\(error)")
return
}
print("response = \(response)")
let responseString = NSString(data: data!, encoding: NSUTF8StringEncoding)
print("responseString = \(responseString)")
}
task.resume()
}
func URLSession(session: NSURLSession, task: NSURLSessionTask, didReceiveChallenge challenge: NSURLAuthenticationChallenge, completionHandler: (NSURLSessionAuthChallengeDisposition, NSURLCredential?) -> Void) {
if challenge.protectionSpace.authenticationMethod == NSURLAuthenticationMethodServerTrust{
let credential = NSURLCredential(forTrust: challenge.protectionSpace.serverTrust!)
completionHandler(NSURLSessionAuthChallengeDisposition.UseCredential,credential);
}
}
}
It looks like the idea is to pick up the challenge event from the connection, and tell it that "yes I want to proceed". But that piece of code does not seem to be getting called. The post request gets sent, but I receive the error messages about the untrusted certificate. Can someone help me fix my code so that I can accept this certificate from my server?

Answer 1

You need to make your ViewController NSURLSessionDelegate to receive the callbacks and set the session's delegate to be your controller, like this:
let configuration = NSURLSessionConfiguration.defaultSessionConfiguration()
let session = NSURLSession(configuration: configuration, delegate: self, delegateQueue: nil)
...
let task = session.dataTaskWithRequest(request) { data, response, error in
}
task.resume()

Answer 2

You cannot use the shared session to get those delegate methods. You must instantiate a new NSURLSession and declare yourself as the delegate.
// Delegate methods won't be callend
let task = NSURLSession.sharedSession()...
// Use this to get delegate calls
let task = NSURLSession(configuration: NSURLSessionConfiguration.defaultSessionConfiguration(),
delegate: self,
delegateQueue: /* make a queue */)...
With iOS 9, you will also need to look into NSAppTransportSecurity and adding those keys to your plist. These are needed in iOS 9 to allow SSL connections.