Touch-ID authentication

let touchIDContext = LAContext()
var touchIDError : NSError?
let reasonString = "Too much control for more then one person"

// Check if we can access local device authentication
if touchIDContext.canEvaluatePolicy(LAPolicy.deviceOwnerAuthenticationWithBiometrics, error:&touchIDError) {
        // Initiate authentication
        touchIDContext.evaluatePolicy(LAPolicy.deviceOwnerAuthenticationWithBiometrics, localizedReason: reasonString, reply: {
                (success: Bool, error: Error?) -> Void in
                // Check if authentication was successful
                if success {
                        // Do something after authentication
                        userAuthenticated()
                }
        } )
} else {
        // No Touch-ID sensor, proceed to manual PIN entry
        initPinAuth()
}