ios - Swift 4 - 重新验证 FaceID

Question

我在我的应用程序上实现了面部 ID 身份验证，用户在点击按钮时获得身份验证。我还实现了一个将用户注销的注销方法:

dismiss(animated: true, completion: {

UserDefaults.standard.set(false, forKey: "hasLoginKey")

})

但是，当我注销然后尝试重新登录时，系统没有提示我输入 FaceID，而是跳过它，我完全登录了。我的问题是如何防止这种情况并在用户每次点击按钮时提示他们登录？

这是按钮代码:

@IBAction func loginButtonPressed(_ sender: Any) {

        //Define Button variable from the button that has been tapped.
        let button = sender as! UIButton

        //If the button tag is Touch ID, authenticate the user

        if(button.tag == loginWithTouchID)
        {
            //Check if device is compatible with Touch ID
            if(touchMe.canEvaluatePolicy())
            {
                //Get Response from Touch ID popup
                touchMe.authenticateUser() { responsCode in

                    if let responsCode = responsCode {

                        if(responsCode == 0)
                        {
                            //If Touch ID is not available
                            self.customAlert(title: "Error", message: "Touch ID not available")
                        }
                        else if(responsCode == 1)
                        {
                            //If Touch ID has not been setup
                            self.customAlert(title: "Error", message: "Touch ID may not be configured")
                        }
                        else if(responsCode == 2)
                        {
                            //If Touch ID authentication failed
                            self.customAlert(title: "Error", message: "There was a problem verifying your identity")
                        }

                    } else {

                        //If there is no response code, that means Touch ID was successful in authenticating user and we can now call the login method
                        Timer.scheduledTimer(timeInterval: 0.4, target: self, selector: #selector(Login.login), userInfo: nil, repeats: false)
                    }
                }
            }
        }
        else
        {
            Timer.scheduledTimer(timeInterval: 0.4, target: self, selector: #selector(Login.login), userInfo: nil, repeats: false)
        }


    }

和我的 TouchIDAuth 类

class TouchIDAuth {

    let context = LAContext()

    func canEvaluatePolicy() -> Bool {
        return context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil)
    }

    func authenticateUser(completion: @escaping (NSNumber?) -> Void) {

        guard canEvaluatePolicy() else {
            completion(0)
            return
        }

        context.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, localizedReason: "Logging in with Touch ID") { (success, evaluateError) in
            if success {
                DispatchQueue.main.async {
                    completion(nil)
                }
            } else {

                let response: NSNumber

                switch evaluateError?._code {
                case Int(kLAErrorAuthenticationFailed):
                    response = 2
                case Int(kLAErrorUserCancel):
                    response = 3
                case Int(kLAErrorUserFallback):
                    response = 4
                default:
                    response = 1
                }

                completion(response)

            }
        }
    }

}

这是在按下按钮的方法中调用的登录方法

@objc func login() {

        //Start Activity Indicator

        self.createIndicator()

        //Define Username and Password Variables

        var user: String!
        var pass: String!


        //Check if User is Authenticating with TouchID, we do this so we know to use credentials from Keychain to make the API call with
        if(loginButton.tag == loginWithTouchID)
        {
            //If Yes, Get the username from Keychain
            if let storedUsername = UserDefaults.standard.value(forKey: "username") as? String {

                //Get Password from Keychain

                do {

                    let passwordItem = KeychainPasswordItem(service: KeychainConfiguration.serviceName,
                                                            account: storedUsername,
                                                            accessGroup: KeychainConfiguration.accessGroup)
                    let keychainPassword = try passwordItem.readPassword()

                    //Store Username and Password from Keychain into Username and Password variables

                    user = storedUsername
                    pass = keychainPassword

                }
                catch {

                    //If something went wrong, stop the Activity Indicator and Alert the user something went wrong.

                    self.stopIndicator()

                    self.customAlert(title: "Error", message: "Error reading password from keychain - \(error)")
                }

            }
        }
        else
        {
            //If we are not using Touch ID, store the username and password text field into the username and password variable to use for the API Call

            user = username.text!
            pass = password.text!
        }

        //Finally call the webservice

        WebService().loginUser(user, password: pass)
        {
            (result: Bool) in
            //If API call is successful
            if(result == true)
            {

                //Stop Activity Indicator

                self.stopIndicator()

                //Check if button tag is create, login or touch ID

                if self.loginButton.tag == self.createLoginButtonTag {

                    //If create, check if a user has login

                    let hasLoginKey = UserDefaults.standard.bool(forKey: "hasLoginKey")
                    if !hasLoginKey {

                        //If not, add username to App Default

                        UserDefaults.standard.setValue(user, forKey: "username")
                    }

                    //Try and save the password to Keychain

                    do {

                        //Create a KeychainPasswordItem

                        let passwordItem = KeychainPasswordItem(service: KeychainConfiguration.serviceName, account: user!, accessGroup: KeychainConfiguration.accessGroup)

                        //Save password to the new KeychainPasswordItem

                        try passwordItem.savePassword(pass!)

                        //Add hasLoginKey bool to App Defaults

                        UserDefaults.standard.set(true, forKey: "hasLoginKey")

                        //Change Login button tag to Login as we do not need to create this user again

                        self.loginButton.tag = self.loginButtonTag

                        //Store Credentials to App Delegate to make API calls down the road.

                        self.appDelegate.username = user
                        self.appDelegate.password = pass

                        self.password.text = ""

                        //Everything has been authenticated, proceed to Dashboad

                        self.performSegue(withIdentifier: "toolbarSegue", sender: nil)


                    } catch {

                        //Something went wrong, alert the user with error.

                        self.customAlert(title: "Error", message: "Error updating keychain - \(error)")

                    }

                }
                    //If Login Button tag with Login
                else if self.loginButton.tag == self.loginButtonTag {

                    //Check if user exists in Keychain

                    if self.checkLogin(username: user, password: pass) {

                        //Store Credentials to App Delegate to make API calls down the road.

                        self.appDelegate.username = user
                        self.appDelegate.password = pass

                        self.password.text = ""

                        //Exisiting user has been authenticated, proceed to Dashboad

                        self.performSegue(withIdentifier: "toolbarSegue", sender: nil)

                    } else {

                        //User does not exist in Keychain, alert user there is an error.

                        self.customAlert(title: "Login Problem", message: "Sorry Login Failed, User and/or Passsword Incorrect")
                    }

                }
                    //If Login Button tag with Touch ID
                else if self.loginButton.tag == self.loginWithTouchID {

                    //Store Credentials to App Delegate to make API calls down the road.

                    self.appDelegate.username = user
                    self.appDelegate.password = pass

                    self.password.text = ""

                    //Touch ID has been authenticated, proceed to Dashboad

                    self.performSegue(withIdentifier: "toolbarSegue", sender: nil)

                }

            }
            else
            {

                //Stop Activity Indicator

                self.stopIndicator()

                //API call was unsuccessful, alert user.

                self.customAlert(title: "Login Problem", message: "Sorry Login Failed, User and/or Passsword Incorrect")

            }

        }


    }

Answer 1

我认为您正在更改 login 中的登录按钮标签，在这一行中:

//Change Login button tag to Login as we do not need to create this user again, as you have specified

self.loginButton.tag = self.loginButtonTag

这就是为什么当用户下次点击登录按钮时，它会直接验证用户(因为条件为false):

 if(button.tag == loginWithTouchID) {
      // login with touchID
else {
      // authenticate the user
}

所以我认为你不应该改变 self.loginButton.tag