ios - 在 AWS iOS SDK 中，如何处理 FORCE_CHANGE_PASSWORD 用户状态

Question

我已经按照这里的示例

https://github.com/awslabs/aws-sdk-ios-samples/tree/master/CognitoYourUserPools-Sample

将交互式 Cognito 登录集成到我的 iOS 应用程序中。这一切都运行良好，但是当在池中创建新用户时，他们最初具有 FORCE_CHANGE_PASSWORD 状态。

对于安卓你可以按照下面的步骤

http://docs.aws.amazon.com/cognito/latest/developerguide/using-amazon-cognito-user-identity-pools-android-sdk-authenticate-admin-created-user.html

但对于 iOS，我无法找到如何执行此操作。使用示例，如果我尝试使用处于 FORCE_CHANGE_PASSWORD 状态的用户登录，我会在控制台日志中看到以下输出(为简洁起见删除了一些值):

{"ChallengeName":"NEW_PASSWORD_REQUIRED","ChallengeParameters":{"requiredAttributes":"[]","userAttributes":"{\"email_verified\":\"true\",\"custom:autoconfirm\":\"Y\","Session":"xyz"}

以下是上述示例中 SignInViewController 的代码。

import Foundation
import AWSCognitoIdentityProvider

class SignInViewController: UIViewController {
    @IBOutlet weak var username: UITextField!
    @IBOutlet weak var password: UITextField!
    var passwordAuthenticationCompletion: AWSTaskCompletionSource<AWSCognitoIdentityPasswordAuthenticationDetails>?
    var usernameText: String?

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        self.password.text = nil
        self.username.text = usernameText
        self.navigationController?.setNavigationBarHidden(true,   animated: false)
    }

    @IBAction func signInPressed(_ sender: AnyObject) {
        if (self.username.text != nil && self.password.text != nil) {
            let authDetails = AWSCognitoIdentityPasswordAuthenticationDetails(username: self.username.text!, password: self.password.text! )
            self.passwordAuthenticationCompletion?.set(result: authDetails)
        } else {
            let alertController = UIAlertController(title: "Missing information",
                                                message: "Please enter a valid user name and password",
                                                preferredStyle: .alert)
            let retryAction = UIAlertAction(title: "Retry", style: .default, handler: nil)
            alertController.addAction(retryAction)
        }
    }
}

extension SignInViewController: AWSCognitoIdentityPasswordAuthentication {

    public func getDetails(_ authenticationInput: AWSCognitoIdentityPasswordAuthenticationInput, passwordAuthenticationCompletionSource: AWSTaskCompletionSource<AWSCognitoIdentityPasswordAuthenticationDetails>)     {
        self.passwordAuthenticationCompletion = passwordAuthenticationCompletionSource
        DispatchQueue.main.async {
            if (self.usernameText == nil) {
                self.usernameText = authenticationInput.lastKnownUsername
            }
        }
    }

    public func didCompleteStepWithError(_ error: Error?) {
        DispatchQueue.main.async {
        if let error = error as? NSError {
            let alertController = UIAlertController(title: error.userInfo["__type"] as? String,
                                                    message: error.userInfo["message"] as? String,
                                                    preferredStyle: .alert)
            let retryAction = UIAlertAction(title: "Retry", style: .default, handler: nil)
            alertController.addAction(retryAction)

            self.present(alertController, animated: true, completion:  nil)
            } else {
                self.username.text = nil
                self.dismiss(animated: true, completion: nil)
            }
        }
    }
}

当 didCompleteStepWithError 执行时，error 为 null，我希望它指示一些东西告诉我们用户需要更改密码。

我的问题实际上是如何捕获输出到控制台的 "ChallengeName":"NEW_PASSWORD_REQUIRED" json？

Answer 1

现在整理一下。将它张贴在这里以防它对其他人有帮助。

首先，您需要创建一个允许用户指定新密码的 View Controller 。 ViewController 应该有一个 AWSTaskCompletionSource<AWSCognitoIdentityNewPasswordRequiredDetails>作为属性(property):

var newPasswordCompletion: AWSTaskCompletionSource<AWSCognitoIdentityNewPasswordRequiredDetails>?

按照问题中提到的示例中的模式，我随后实现了 AWSCognitoIdentityNewPasswordRequired作为 View Controller 的扩展，如下所示:

extension NewPasswordRequiredViewController: AWSCognitoIdentityNewPasswordRequired {
    func getNewPasswordDetails(_ newPasswordRequiredInput: AWSCognitoIdentityNewPasswordRequiredInput, newPasswordRequiredCompletionSource:
    AWSTaskCompletionSource<AWSCognitoIdentityNewPasswordRequiredDetails>) {                    
        self.newPasswordCompletion = newPasswordRequiredCompletionSource
    }

    func didCompleteNewPasswordStepWithError(_ error: Error?) {
        if let error = error as? NSError {
            // Handle error
        } else {
            // Handle success, in my case simply dismiss the view controller
            self.dismiss(animated: true, completion: nil)
        }
    }

}

再次按照问题中详述的示例设计，向 AWSCognitoIdentityInteractiveAuthenticationDelegate 添加一个函数AppDelegate 的扩展:

extension AppDelegate: AWSCognitoIdentityInteractiveAuthenticationDelegate {
    func startPasswordAuthentication() -> AWSCognitoIdentityPasswordAuthentication {
        //Existing implementation
    }
    func startNewPasswordRequired() -> AWSCognitoIdentityNewPasswordRequired {
        // Your code to handle how the NewPasswordRequiredViewController is created / presented, the view controller should be returned
        return self.newPasswordRequiredViewController!
    }
}