Travailler avec des utilisateurs multifacteur

Ce document explique comment effectuer des tâches courantes avec des utilisateurs d'Identity Platform inscrits à l'authentification multifacteur.

Mettre à jour l'adresse e-mail d'un utilisateur

Les utilisateurs multifacteur doivent toujours disposer d'une adresse e-mail validée. Cela empêche les utilisateurs malveillants de s'enregistrer à votre application avec une adresse e-mail dont ils ne sont pas propriétaire, puis de bloquer le propriétaire réel en ajoutant un second facteur.

Pour mettre à jour l'adresse e-mail d'un utilisateur, utilisez la méthode verifyBeforeUpdateEmail(). Contrairement à updateEmail(), cette méthode oblige l'utilisateur à suivre un lien de validation avant de mettre à jour son adresse e-mail. Exemple :

Version 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.
});

Version 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.
         }
       }
      });

Par défaut, Identity Platform envoie un e-mail à l'utilisateur et fournit un gestionnaire Web simple pour traiter la vérification. Vous pouvez personnaliser ce flux de différentes manières.

Localiser les e-mails de validation

Pour localiser les e-mails envoyés par Identity Platform, définissez le code de langue avant d'appeler verifyBeforeUpdateEmail() :

Version Web 8

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

Version Web 9

import { getAuth } from "firebase/auth";

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

iOS

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

Android

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

Transmettre un état supplémentaire

Vous pouvez utiliser des paramètres de code d'action pour inclure un état supplémentaire dans l'e-mail de validation ou gérer la validation depuis une application mobile. Exemple :

Version 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.
});

Version 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.
         }
       }
      });

Personnaliser le gestionnaire de validation

Vous pouvez créer votre propre gestionnaire pour traiter la validation de l'adresse e-mail. L'exemple suivant montre comment vérifier un code d'action et inspecter ses métadonnées avant de l'appliquer :

Version 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.
  });

Version 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.
      }
    }
  });

Pour en savoir plus, consultez la documentation Firebase consacrée à la création de gestionnaires d'actions de messagerie personnalisés.

Réauthentifier un utilisateur

Même si un utilisateur est déjà connecté, vous pouvez choisir de le réauthentifier avant d'effectuer des opérations sensibles, telles que :

• Modifier un mot de passe
• Ajouter ou supprimer un nouveau second facteur
• Mettre à jour des informations personnelles (une adresse, par exemple)
• Exécuter des transactions financières.
• Supprimer le compte d'un utilisateur

Pour réauthentifier un utilisateur avec une adresse e-mail et un mot de passe :

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.
         }
       }
      });

Pour vous réauthentifier avec un fournisseur OAuth, tel que 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.
         }
       }
      });

Révoquer un second facteur récemment ajouté

Lorsqu'un utilisateur enregistre un second facteur, Identity Platform envoie une notification à son adresse e-mail. Pour empêcher les activités non autorisées, l'e-mail inclut une option permettant d'annuler l'ajout d'un second facteur.

Identity Platform fournit un modèle et un gestionnaire d'e-mails par défaut, mais vous pouvez également créer le vôtre. L'exemple suivant montre comment créer un gestionnaire personnalisé :

Version 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.
  });

Version 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.
          }
        }
      });

Pour en savoir plus, consultez la documentation Firebase consacrée à la création de gestionnaires d'actions de messagerie personnalisés.

Récupérer un second facteur

Identity Platform ne fournit pas de mécanisme intégré pour récupérer les seconds facteurs. Si un utilisateur perd l'accès à son second facteur, son accès à son compte est verrouillé. Pour éviter cela, envisagez de prendre les mesures suivantes :

• Avertissez les utilisateurs que, sans leur second facteur, ils perdront l'accès à leur compte.
• Encouragez fortement les utilisateurs à enregistrer un facteur secondaire de sauvegarde.
• Utilisez le SDK Admin pour créer un flux de récupération qui désactive l'authentification multifacteur si l'utilisateur peut suffisamment valider son identité (par exemple, en important une clé ou en répondant à des questions personnelles).
• Accordez à votre équipe d'assistance la possibilité de gérer les comptes utilisateur (y compris de supprimer des seconds facteurs) et permettez aux utilisateurs de la contacter s'ils n'ont plus accès à leur compte.

La réinitialisation du mot de passe ne permet pas à un utilisateur de contourner l'authentification multifacteur. Si vous réinitialisez le mot de passe d'un utilisateur à l'aide de sendPasswordResetEmail(), il devra toujours réussir l'authentification multifacteur lors de la connexion avec son nouveau mot de passe.

Désinscrire un second facteur

Pour désinscrire un second facteur, récupérez celui-ci dans la liste des facteurs inscrits de l'utilisateur, puis appelez unenroll(). Comme il s'agit d'une opération sensible, vous devez d'abord réauthentifier l'utilisateur s'il ne s'est pas connecté récemment.

Version 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.
  });

Version 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.
         }
       }
      });

Dans certains cas, l'utilisateur peut être déconnecté après avoir supprimé un second facteur. Utilisez onAuthStateChanged() pour écouter ce cas et demandez à l'utilisateur de se reconnecter.

Étapes suivantes

• Ajouter l'authentification multifacteur à votre application Web, iOS ou Android.

• Gérer des utilisateurs multifacteur par programmation.