Dismiss TouchID authentication about ellipticcurvekeypair HOT 13 OPEN

import UIKit
import LocalAuthentication

class ViewController: UIViewController {

    var context: LAContext! = LAContext()
    
    func createAccessControl(protection: CFString = kSecAttrAccessibleWhenPasscodeSetThisDeviceOnly, flags: SecAccessControlCreateFlags = [.userPresence, .privateKeyUsage]) -> SecAccessControl {
        var error: Unmanaged<CFError>?
        let accessControl = SecAccessControlCreateWithFlags(kCFAllocatorDefault, protection, flags, &error)
        return accessControl!
    }
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        delay(1.0, queue: .main) {
            self.decrypt()
        }
    }
    
    func decrypt() {
        
        let accessControl = createAccessControl()
        context.evaluateAccessControl(accessControl, operation: .useKeySign, localizedReason: "Sign") { (success, error) in
            DispatchQueue.main.async {
                if success {
                    let alert = UIAlertController(title: "Authenticated", message: "Ready to sign/decrypt", preferredStyle: .alert)
                    alert.addAction(UIAlertAction(title: "OK", style: .cancel, handler: nil))
                    self.show(alert, sender: nil)
                } else {
                    let alert = UIAlertController(title: "Failed to authenticate", message: "Error: \(error!)", preferredStyle: .alert)
                    alert.addAction(UIAlertAction(title: "OK", style: .cancel, handler: nil))
                    self.show(alert, sender: nil)
                }
            }
        }
        
        delay(3.0, queue: .main) {
            self.context.invalidate()
        }
    }
}

func delay( _ delay: Double, queue: DispatchQueue, completion: @escaping () -> () ) {
    queue.asyncAfter(deadline: DispatchTime.now() + Double(Int64(delay * Double(NSEC_PER_SEC))) / Double(NSEC_PER_SEC)) { () -> Void in
        completion()
    }
}