Attività con utenti con autenticazione a più fattori

Questo documento mostra come eseguire attività comuni con gli utenti di Identity Platform registrati per l'autenticazione a più fattori.

Aggiornamento dell'email di un utente

Gli utenti con autenticazione a più fattori devono sempre avere un indirizzo email verificato. In questo modo, gli utenti malintenzionati non possono registrarsi alla tua app con un indirizzo email di cui non sono proprietari e bloccare il proprietario reale aggiungendo un secondo fattore.

Per aggiornare l'email di un utente, utilizza il metodo verifyBeforeUpdateEmail(). A differenza di updateEmail(), questo metodo richiede all'utente di seguire un link di verifica prima che Identity Platform aggiorni il suo indirizzo email. Ad esempio:

Versione web 8 

var user = firebase.auth().currentUser;
user.verifyBeforeUpdateEmail(newEmail).then(function() {
  // Email sent.
  // User must click the email link before the email is updated.
}).catch(function(error) {
  // An error happened.
});

Versione web 9 

import { getAuth, verifyBeforeUpdateEmail } from "firebase/auth";

const auth = getAuth(firebaseApp);
verifyBeforeUpdateEmail(auth.currentUser, newEmail).then(() => {
  // Email sent.
  // User must click the email link before the email is updated.
}).catch((error) => {
  // An error happened.
});

iOS 

let user = Auth.auth().currentUser
user.verifyBeforeUpdateEmail(newEmail, completion: { (error) in
  if error != nil {
    // An error happened.
  }
  // Email sent.
  // User must click the email link before the email is updated.
})

Android 

FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
user.verifyBeforeUpdateEmail(newEmail)
   .addOnCompleteListener(
      new OnCompleteListener<Void>() {
       @Override
       public void onComplete(@NonNull Task<Void> task) {
         if (task.isSuccessful()) {
          // Email sent.
          // User must click the email link before the email is updated.
         } else {
          // An error occurred.
         }
       }
      });

Per impostazione predefinita, Identity Platform invia all'utente un'email e fornisce un semplice gestore basato su web per elaborare la verifica. Esistono diversi modi per personalizzare questo flusso.

Localizzazione delle email di verifica

Per localizzare le email inviate da Identity Platform, imposta il codice lingua prima di chiamare verifyBeforeUpdateEmail():

Versione web 8 

firebase.auth().languageCode = 'fr';

Versione web 9 

import { getAuth } from "firebase/auth";

const auth = getAuth();
auth.languageCode = 'fr';

iOS 

Auth.auth().languageCode = 'fr';

Android 

FirebaseAuth.getInstance().setLanguageCode("fr");

Passaggio di uno stato aggiuntivo

Puoi utilizzare le impostazioni del codice di azione per includere uno stato aggiuntivo nell'email di verifica o gestire la verifica da un'app mobile. Ad esempio:

Versione web 8 

var user = firebase.auth().currentUser;
var actionCodeSettings = {
  url: 'https://www.example.com/completeVerification?state=*****',
  iOS: {
    bundleId: 'com.example.ios'
  },
  android: {
    packageName: 'com.example.android',
    installApp: true,
    minimumVersion: '12'
  },
  handleCodeInApp: true,
  // When multiple custom dynamic link domains are defined, specify which
  // one to use.
  dynamicLinkDomain: "example.page.link"
};
user.verifyBeforeUpdateEmail(newEmail, actionCodeSettings).then(function() {
  // Email sent.
  // User must click the email link before the email is updated.
}).catch(function(error) {
  // An error happened.
});

Versione web 9 

import { getAuth, verifyBeforeUpdateEmail } from "firebase/auth";

const auth = getAuth(firebaseApp);
const user = auth.currentUser
const actionCodeSettings = {
  url: 'https://www.example.com/completeVerification?state=*****',
  iOS: {
    bundleId: 'com.example.ios'
  },
  android: {
    packageName: 'com.example.android',
    installApp: true,
    minimumVersion: '12'
  },
  handleCodeInApp: true,
  // When multiple custom dynamic link domains are defined, specify which
  // one to use.
  dynamicLinkDomain: "example.page.link"
};

  verifyBeforeUpdateEmail(auth.currentUser, newEmail, actionCodeSettings).then(() => {
    // Email sent.
    // User must click the email link before the email is updated.
  }).catch((error) => {
    // An error happened.
  })

iOS 

var actionCodeSettings = ActionCodeSettings.init()
actionCodeSettings.canHandleInApp = true
let user = Auth.auth().currentUser()
actionCodeSettings.URL =
    String(format: "https://www.example.com/?email=%@", user.email)
actionCodeSettings.iOSbundleID = Bundle.main.bundleIdentifier!
actionCodeSettings.setAndroidPakageName("com.example.android",
                                         installIfNotAvailable:true,
                                         minimumVersion:"12")
// When multiple custom dynamic link domains are defined, specify which one to use.
actionCodeSettings.dynamicLinkDomain = "example.page.link"
user.sendEmailVerification(withActionCodeSettings:actionCodeSettings { error in
  if error != nil {
    // Error occurred. Inspect error.code and handle error.
    return
  }
  // Email verification sent.
})
user.verifyBeforeUpdateEmail(newEmail, actionCodeSettings, completion: { (error) in
  if error != nil {
    // An error happened.
  }
  // Email sent.
  // User must click the email link before the email is updated.
})

Android 

ActionCodeSettings actionCodeSettings =
    ActionCodeSettings.newBuilder()
       .setUrl("https://www.example.com/completeVerification?state=*****")
       .setHandleCodeInApp(true)
       .setAndroidPackageName(
         "com.example.android",
         /* installIfNotAvailable= */ true,
         /* minimumVersion= */ null)
       .setIOSBundleId("com.example.ios")
       // When multiple custom dynamic link domains are defined, specify
       // which one to use.
       .setDynamicLinkDomain("example.page.link")
       .build();
FirebaseUser multiFactorUser = FirebaseAuth.getInstance().getCurrentUser();
multiFactorUser
   .verifyBeforeUpdateEmail(newEmail, actionCodeSettings)
   .addOnCompleteListener(
      new OnCompleteListener<Void>() {
       @Override
       public void onComplete(@NonNull Task<Void> task) {
         if (task.isSuccessful()) {
          // Email sent.
          // User must click the email link before the email is updated.
         } else {
          // An error occurred.
         }
       }
      });

Personalizzazione del gestore di verifica

Puoi creare il tuo gestore per elaborare la verifica email. L'esempio seguente mostra come controllare un codice di azione e ispezionarne i metadati prima di applicarlo:

Versione web 8 

var email;
firebase.auth().checkActionCode(actionCode)
  .then(function(info) {
    // Operation is equal to
    // firebase.auth.ActionCodeInfo.Operation.VERIFY_AND_CHANGE_EMAIL
    var operation = info['operation'];
    // This is the old email.
    var previousEmail = info['data']['previousEmail'];
    // This is the new email the user is changing to.
    email = info['data']['email'];
    // TODO: Display a message to the end user that the email address of the account is
    // going to be changed from `fromEmail` to `email`
    // …
    // On confirmation.
    return firebase.auth().applyActionCode(actionCode)
  }).then(function() {
    // Confirm to the end user the email was updated.
    showUI('You can now sign in with your new email: ' + email);
  })
  .catch(function(error) {
    // Error occurred during confirmation. The code might have expired or the
    // link has been used before.
  });

Versione web 9 

import { getAuth,  checkActionCode, applyActionCode} from "firebase/auth";

const auth = getAuth(firebaseApp);
var email;
checkActionCode(auth, actionCode)
  .then((info) => {
    // Operation is equal to
    // ActionCodeOperation.VERIFY_AND_CHANGE_EMAIL
    const operation = info['operation'];
    // This is the old email.
    const previousEmail = info['data']['previousEmail'];
    // This is the new email the user is changing to.
    email = info['data']['email'];
    // TODO: Display a message to the end user that the email address of the account is
    // going to be changed from `fromEmail` to `email`
    // …
    // On confirmation.
    return applyActionCode(auth, actionCode)
  }).then(() => {
    // Confirm to the end user the email was updated.
    showUI('You can now sign in with your new email: ' + email);
  })
  .catch((error) => {
    // Error occurred during confirmation. The code might have expired or the
    // link has been used before.
  });

iOS 

Auth.auth().checkActionCode(actionCode) { info, error in
  if error != nil {
    // Error occurred during confirmation. The code might have expired or the
    // link has been used before.
    return
  }
  // This is the new email the user is changing to.
  let email = info?.email
  // This is the old email.
  let oldEmail = info?.previousEmail
  // operation is equal to
  // firebase.auth.ActionCodeInfo.Operation.VERIFY_AND_CHANGE_EMAIL
  let operation = info?.operation
  // TODO: Display a message to the end user that the email address of the account is
  // going to be changed from `fromEmail` to `email`
  // …
  // On confirmation.
  return Auth.auth().applyActionCode(actionCode)
}

Android 

FirebaseAuth.getInstance().checkActionCode(actionCode).addOnCompleteListener(
  new OnCompleteListener<ActionCodeResult>() {
    @Override
    public void onComplete(@NonNull Task<ActionCodeResult> task) {
      if (!task.isSuccessful()) {
        // Error occurred during confirmation. The code might have expired or the
        // link has been used before.
        return;
      }
      ActionCodeResult result = task.getResult();

      // This maps to VERIFY_AND_CHANGE_EMAIL.
      int operation = result.getOperation();

      if (operation == ActionCodeResult.VERIFY_AND_CHANGE_EMAIL) {
        ActionCodeEmailInfo actionCodeInfo =
            (ActionCodeEmailInfo) result.getInfo();

        String fromEmail = actionCodeInfo.getFromEmail();
        String email = actionCodeInfo.getEmail();
        // TODO: Display a message to the user that the email address
        // of the account is changing from `fromEmail` to `email` once
        // they confirm.
      }
    }
  });

Per scoprire di più, consulta la documentazione di Firebase su come creare gestori di azioni email personalizzati.

Autenticazione di un utente

Anche se un utente ha già eseguito l'accesso, ti consigliamo di eseguire nuovamente l'autenticazione prima di eseguire operazioni sensibili, ad esempio:

  • Modifica di una password.
  • Aggiunta o rimozione di un nuovo secondo fattore.
  • Aggiornamento di informazioni personali (ad esempio un indirizzo).
  • Esecuzione di transazioni finanziarie.
  • Eliminazione dell'account di un utente.

Per autenticare nuovamente un utente con email e password:

Web 

var resolver;
var credential = firebase.auth.EmailAuthProvider.credential(
    firebase.auth().currentUser.email, password);
firebase.auth().currentUser.reauthenticateWithCredential(credential)
  .then(function(userCredential) {
    // User successfully re-authenticated and does not require a second factor challenge.
    // ...
  })
  .catch(function(error) {
    if (error.code == 'auth/multi-factor-auth-required') {
      // Handle multi-factor authentication.
    } else {
      // Handle other errors.
    }
  });

iOS 

let credential = EmailAuthProvider.credential(withEmail: email, password: password)
Auth.auth().currentUser.reauthenticate(with: credential, completion: { (result, error) in
  let authError = error as NSError?
  if (authError == nil || authError!.code != AuthErrorCode.secondFactorRequired.rawValue) {
    // User is not enrolled with a second factor or is successfully signed in.
  } else {
    // Handle multi-factor authentication.
  }
})

Android 

FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
AuthCredential credential = EmailAuthProvider.getCredential(user.getEmail(), password);
user.reauthenticate(credential)
   .addOnCompleteListener(
      new OnCompleteListener<AuthResult>() {
       @Override
       public void onComplete(@NonNull Task<AuthResult> task) {
         if (task.isSuccessful()) {
          // User successfully re-authenticated and does not
          // require a second factor challenge.
          // ...
          return;
         }
         if (task.getException() instanceof FirebaseAuthMultiFactorException) {
           // Handle multi-factor authentication.
         } else {
          // Handle other errors.
         }
       }
      });

Per eseguire nuovamente l'autenticazione utilizzando un provider OAuth, ad esempio Microsoft:

Web 

var resolver;
var user = firebase.auth().currentUser;
// Ask the user to re-authenticate with Microsoft.
var provider = new firebase.auth.OAuthProvider('microsoft.com');
// Microsoft provider allows the ability to provide a login_hint.
provider.setCustomParameters({
  login_hint: user.email
});
user.reauthenticateWithPopup(provider)
  .then(function(userCredential) {
    // User successfully re-authenticated and does not require a second factor challenge.
    // ...
  })
  .catch(function(error) {
    if (error.code == 'auth/multi-factor-auth-required') {
      // Handle multi-factor authentication.
    } else {
      // Unsupported second factor.
    } else {
      // Handle other errors.
    }
  });

iOS 

var provider = OAuthProvider(providerID: "microsoft.com")
  // Replace nil with the custom class that conforms to AuthUIDelegate
  // you created in last step to use a customized web view.
  provider.getCredentialWith(nil) { credential, error in
    Auth.auth().currentUser.reauthenticate(with: credential, completion: { (result, error) in
      let authError = error as NSError?
      if (authError == nil || authError!.code != AuthErrorCode.secondFactorRequired.rawValue) {
        // User is not enrolled with a second factor or is successfully signed in.
        // ...
      } else {
        // Handle multi-factor authentication.
      }
    }
  })

Android 

FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
OAuthProvider.Builder provider = OAuthProvider.newBuilder("microsoft.com");
provider.addCustomParameter("login_hint", user.getEmail());
user.startActivityForReauthenticateWithProvider(/* activity= */ this, provider.build())
   .addOnCompleteListener(
      new OnCompleteListener<AuthResult>() {
       @Override
       public void onComplete(@NonNull Task<AuthResult> task) {
         if (task.isSuccessful()) {
          // User successfully re-authenticated and does not
          // require a second factor challenge.
          // ...
          return;
         }
         if (task.getException() instanceof FirebaseAuthMultiFactorException) {
           // Handle multi-factor authentication.
         } else {
          // Handle other errors such as wrong password.
         }
       }
      });

Revocare un secondo fattore aggiunto di recente

Quando un utente registra un secondo fattore, Identity Platform invia una notifica alla sua email. Per proteggerti da attività non autorizzate, l'email include un'opzione per annullare l'aggiunta di un secondo fattore.

Identity Platform fornisce un modello e un gestore email predefiniti, ma puoi anche crearne uno personalizzato. L'esempio seguente mostra come creare un gestore personalizzato:

Versione web 8 

var obfuscatedPhoneNumber;
firebase.auth().checkActionCode(actionCode)
  .then(function(info) {
    // operation is equal to
    // firebase.auth.ActionCodeInfo.Operation.REVERT_SECOND_FACTOR_ADDITION
    var operation = info['operation'];
    // info.data.multiFactorInfo contains the data corresponding to the
    // enrolled second factor that the user is revoking.
    var multiFactorInfo = info['data']['multiFactorInfo'];
    obfuscatedPhoneNumber = multiFactorInfo['phoneNumber'];
    var displayName = multiFactorInfo['displayName'];
    // TODO: Display a message to the end user about the second factor that
    // was enrolled before the user can confirm the action to revert it.
    // ...
    // On confirmation.
    return firebase.auth().applyActionCode(actionCode)
  }).then(function() {
    // Confirm to the end user the phone number was removed from the account.
    showUI('The phone number ' + obfuscatedPhoneNumber +
         ' has been removed as a second factor from your account.' +
         ' You may also want to reset your password if you suspect' +
         ' your account was compromised.');
  })
  .catch(function(error) {
    // Error occurred during confirmation. The code might have expired or the
    // link has been used before.
  });

Versione web 9 

const {
  getAuth,
  checkActionCode,
  applyActionCode
} = require("firebase/auth");

const auth = getAuth(firebaseApp);
var obfuscatedPhoneNumber;
checkActionCode(auth, actionCode)
  .then((info) => {
    // Operation is equal to
    // ActionCodeOperation.REVERT_SECOND_FACTOR_ADDITION
    const operation = info['operation'];
    // info.data.multiFactorInfo contains the data corresponding to the
    // enrolled second factor that the user is revoking.
    var multiFactorInfo = info['data']['multiFactorInfo'];
    obfuscatedPhoneNumber = multiFactorInfo['phoneNumber'];
    const displayName = multiFactorInfo['displayName'];
    // TODO: Display a message to the end user about the second factor that
    // was enrolled before the user can confirm the action to revert it.
    // ...
    // On confirmation.
    return applyActionCode(auth, actionCode)
  }).then(() => {
    // Confirm to the end user the phone number was removed from the account.
    showUI('The phone number ' + obfuscatedPhoneNumber +
         ' has been removed as a second factor from your account.' +
         ' You may also want to reset your password if you suspect' +
         ' your account was compromised.');
  })
  .catch((error) => {
    // Error occurred during confirmation. The code might have expired or the
    // link has been used before.
  });

iOS 

Auth.auth().checkActionCode(actionCode) { info, error in
  if error != nil {
    // Error occurred during confirmation. The code might have expired or the
    // link has been used before.
    return
  }
  // This is the new email the user is changing to.
  let email = info?.email
  // This is the old email.
  let oldEmail = info?.previousEmail
  // operation is equal to
  // firebase.auth.ActionCodeInfo.Operation.REVERT_SECOND_FACTOR_ADDITION
  let operation = info?.operation
  // info.multiFactorInfo contains the data corresponding to the enrolled second
  // factor that the user is revoking.
  let multiFactorInfo = info?.multiFactorInfo
  let obfuscatedPhoneNumber = (multiFactorInfo as! PhoneMultiFactorInfo).phone
  // TODO: Display a message to the end user that the email address of the account is
  // going to be changed from `fromEmail` to `email`
  // …
  // On confirmation.
  return Auth.auth().applyActionCode(actionCode)
}

Android 

FirebaseAuth.getInstance()
  .checkActionCode(actionCode)
  .continueWithTask(
      new Continuation<ActionCodeResult, Task<Void>>() {
        @Override
        public Task<Void> then(Task<ActionCodeResult> task) throws Exception {
          if (!task.isSuccessful()) {
            // Error occurred during confirmation. The code might have expired
            // or the link has been used before.
            return Tasks.forException(task.getException());
          }
          ActionCodeResult result = task.getResult();
          // The operation is equal to ActionCodeResult.REVERT_SECOND_FACTOR_ADDITION.
          int operation = result.getOperation();
          // The ActionCodeMultiFactorInfo contains the data corresponding to
          // the enrolled second factor that the user is revoking.
          ActionCodeMultiFactorInfo actionCodeInfo =
              (ActionCodeMultiFactorInfo) result.getInfo();
          PhoneMultiFactorInfo multiFactorInfo =
              (PhoneMultiFactorInfo) actionCodeInfo.getMultiFactorInfo();
          String obfuscatedPhoneNumber = multiFactorInfo.getPhoneNumber();
          String displayName = multiFactorInfo.getDisplayName();
          // We can now display a message to the end user about the second
          // factor that was enrolled before they confirm the action to revert
          // it.
          // ...
          // On user confirmation:
          return FirebaseAuth.getInstance().applyActionCode(actionCode);
        }
      })
  .addOnCompleteListener(
      new OnCompleteListener<Void>() {
        @Override
        public void onComplete(Task<Void> task) {
          if (task.isSuccessful()) {
            // Display a message to the user that the second factor
            // has been reverted.
          }
        }
      });

Per scoprire di più, consulta la documentazione di Firebase su come creare gestori di azioni email personalizzati.

Recupero di un secondo fattore

Identity Platform non fornisce un meccanismo integrato per il recupero del secondo fattore. Se un utente perde l'accesso al secondo fattore, non potrà accedere al proprio account. Per evitare che ciò accada, tieni conto di quanto segue:

  • Avvisare gli utenti che perderanno l'accesso al proprio account senza il secondo elemento.
  • Incoraggiare vivamente gli utenti a registrare un fattore secondario di riserva.
  • Utilizzo dell'SDK Admin per creare un flusso di recupero che disattivi l'autenticazione a più fattori se l'utente può verificare sufficientemente la propria identità (ad esempio caricando una chiave di recupero o rispondendo a domande personali).
  • Concedi al tuo team di assistenza la possibilità di gestire gli account utente (inclusa la rimozione dei secondi fattori) e offri agli utenti un'opzione per contattarli se non riescono ad accedere al loro account.

La reimpostazione della password non consente a un utente di bypassare l'autenticazione a più fattori. Se reimposti la password di un utente utilizzando sendPasswordResetEmail(), l'utente dovrà comunque superare la verifica multifattoriale quando accede con la nuova password.

Annullare la registrazione di un secondo fattore

Per annullare la registrazione di un secondo fattore, selezionalo dall'elenco dei fattori registrati dall'utente e chiama unenroll(). Poiché si tratta di un'operazione sensibile, dovrai prima autenticare di nuovo l'utente se non ha eseguito l'accesso di recente.

Versione web 8 

var options = user.multiFactor.enrolledFactors;
// Ask user to select from the enrolled options.
return user.multiFactor.unenroll(options[selectedIndex])
  .then(function() {
    // User successfully unenrolled selected factor.
  });

Versione web 9 

const multiFactorUser = multiFactor(auth.currentUser);
const options = multiFactorUser.enrolledFactors
// Ask user to select from the enrolled options.
return multiFactorUser.unenroll(options[selectedIndex])
  .then(() =>
    // User successfully unenrolled selected factor.
  });

iOS 

// Ask user to select from the enrolled options.
user?.multiFactor.unenroll(with: (user?.multiFactor.enrolledFactors[selectedIndex])!,
  completion: { (error) in
    // ...
})

Android 

List<MultiFactorInfo> options = user.getMultiFactor().getEnrolledFactors();
// Ask user to select from the enrolled options.
user.getMultiFactor()
   .unenroll(options.get(selectedIndex))
   .addOnCompleteListener(
      new OnCompleteListener<Void>() {
       @Override
       public void onComplete(@NonNull Task<Void> task) {
         if (task.isSuccessful()) {
          // Successfully un-enrolled.
         }
       }
      });

In alcuni casi, l'utente potrebbe essere uscito dopo aver rimosso un secondo fattore. Utilizza onAuthStateChanged() per ascoltare questa richiesta e chiedi all'utente di accedere nuovamente.

Passaggi successivi