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本頁面由 Cloud Translation API 翻譯而成。

在網頁應用程式中加入多重驗證機制

如果您已升級至 Firebase Authentication with Identity Platform，即可新增簡訊多重驗證為您的網頁應用程式

多重驗證可提高應用程式安全性。雖然攻擊者經常會竊取密碼和社群媒體帳戶、攔截簡訊，變得更困難

事前準備

請至少啟用一個支援多重驗證的供應商。每個供應商都支援多重驗證，但電話驗證、匿名驗證和 Apple Game Center。
請啟用您要使用簡訊驗證功能的區域。「Firebase」使用完全封鎖簡訊區域政策。預設會以較安全的狀態建立專案
確認應用程式正在驗證使用者的電子郵件地址。MFA 需要電子郵件驗證。這可防止惡意人士利用電子郵件註冊服務成為非擁有人，進而鎖定真正的擁有者。

使用多用戶群架構

如果您啟用多重驗證機制多用戶群環境，請確定除了請按照以下說明操作)：

在 Google Cloud 控制台中，選取要使用的用戶群。

在程式碼中，將 Auth 例項上的 tenantId 欄位設為用戶群 ID。例如：

Web

import { getAuth } from "firebase/auth";

const auth = getAuth(app);
auth.tenantId = "myTenantId1";

Web

firebase.auth().tenantId = 'myTenantId1';

啟用多重驗證

開啟「驗證 >登入方式 Firebase控制台中的頁面。
在「進階」部分中，啟用「簡訊多重驗證」。

請一併輸入要測試應用程式的電話號碼。雖然非必要，但我們強烈建議您註冊測試電話號碼避免開發過程中發生節流現象
如果您尚未授權應用程式的網域，請將網域新增至允許清單 [驗證] > 中的清單設定 Firebase控制台中的頁面。

選擇註冊模式

您可以選擇是否要讓應用程式需要多因素驗證，以及如何以及註冊使用者的時間常見的模式包括：

註冊使用者的第二重驗證在註冊過程中。使用這份草稿方法。
提供可略過的選項，讓使用者在註冊期間註冊第二個步驟。應用程式想鼓勵但不要求進行多因素驗證時他們偏好使用這個方法。
讓使用者能夠在帳戶或設定檔中新增次要驗證條件而非註冊畫面這可以大幅減少同時在進行多因素驗證時。
使用者要存取應用程式時，需要逐步新增第二個驗證步驟強化安全性要求的功能

設定 reCAPTCHA 驗證器

您必須先設定 reCAPTCHA 驗證器，才能傳送簡訊驗證碼。 Firebase 使用 reCAPTCHA 防堵濫用行為，電話號碼驗證要求來自應用程式允許的網域。

您不需要手動設定 reCAPTCHA 用戶端。用戶端 SDK 的 RecaptchaVerifier 物件會自動建立並初始化任何必要物件用戶端金鑰和密鑰。

使用隱形 reCAPTCHA

RecaptchaVerifier 物件支援隱形 reCAPTCHA、通常可以在不需要任何互動的情況下驗證使用者如要使用隱藏式 reCAPTCHA，建立含有 size 參數的 RecaptchaVerifier 為 invisible，並指定啟動多重要素的 UI 元素 ID 註冊：

Web

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

const recaptchaVerifier = new RecaptchaVerifier(getAuth(), "sign-in-button", {
    "size": "invisible",
    "callback": function(response) {
        // reCAPTCHA solved, you can proceed with
        // phoneAuthProvider.verifyPhoneNumber(...).
        onSolvedRecaptcha();
    }
});

Web

var recaptchaVerifier = new firebase.auth.RecaptchaVerifier('sign-in-button', {
'size': 'invisible',
'callback': function(response) {
  // reCAPTCHA solved, you can proceed with phoneAuthProvider.verifyPhoneNumber(...).
  onSolvedRecaptcha();
}
});

使用 reCAPTCHA 小工具

如要使用可見的 reCAPTCHA 小工具，請建立 HTML 元素以納入，然後使用 UI 的 ID 建立 RecaptchaVerifier 物件。都會在 Docker 容器中執行您也可以選擇設定在 reCAPTCHA 已解決或過期：

Web

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

const recaptchaVerifier = new RecaptchaVerifier(
    getAuth(),
    "recaptcha-container",

    // Optional reCAPTCHA parameters.
    {
      "size": "normal",
      "callback": function(response) {
        // reCAPTCHA solved, you can proceed with
        // phoneAuthProvider.verifyPhoneNumber(...).
        onSolvedRecaptcha();
      },
      "expired-callback": function() {
        // Response expired. Ask user to solve reCAPTCHA again.
        // ...
      }
    }
);

Web

var recaptchaVerifier = new firebase.auth.RecaptchaVerifier(
  'recaptcha-container',
  // Optional reCAPTCHA parameters.
  {
    'size': 'normal',
    'callback': function(response) {
      // reCAPTCHA solved, you can proceed with phoneAuthProvider.verifyPhoneNumber(...).
      // ...
      onSolvedRecaptcha();
    },
    'expired-callback': function() {
      // Response expired. Ask user to solve reCAPTCHA again.
      // ...
    }
  });

預先轉譯 reCAPTCHA

您可以視需要在啟動雙重驗證前預先轉譯 reCAPTCHA 註冊：

Web

recaptchaVerifier.render()
    .then(function (widgetId) {
        window.recaptchaWidgetId = widgetId;
    });

Web

recaptchaVerifier.render()
  .then(function(widgetId) {
    window.recaptchaWidgetId = widgetId;
  });

render() 解析後，您會收到 reCAPTCHA 小工具 ID，您可以使用該 ID 呼叫 reCAPTCHA API：

var recaptchaResponse = grecaptcha.getResponse(window.recaptchaWidgetId);

reCAPTCHA 可透過 verify 方法提取這個邏輯，因此您不需要直接處理 grecaptcha 變數。

註冊次要驗證方式

如何為使用者註冊新的次要驗證條件：

重新驗證使用者。
請使用者輸入電話號碼。

注意： Google 會儲存及使用電話號碼改善垃圾內容和濫用行為防止所有 Google 服務共用您的 Google 產品/服務確認您已取得適當的同意聲明才能傳送電話號碼給 Firebase。

請初始化 reCAPTCHA 驗證器，如上一節所示。如果已設定 RecaptchaVerifier 執行個體，請略過這個步驟：

Web

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

const recaptchaVerifier = new RecaptchaVerifier(
  getAuth(),'recaptcha-container-id', undefined);

Web

var recaptchaVerifier = new firebase.auth.RecaptchaVerifier('recaptcha-container-id');

為使用者取得多重要素工作階段：

Web

import { multiFactor } from "firebase/auth";

multiFactor(user).getSession().then(function (multiFactorSession) {
    // ...
});

Web

user.multiFactor.getSession().then(function(multiFactorSession) {
  // ...
})

使用使用者的電話號碼和PhoneInfoOptions 多因素工作階段：

Web

// Specify the phone number and pass the MFA session.
const phoneInfoOptions = {
  phoneNumber: phoneNumber,
  session: multiFactorSession
};

Web

// Specify the phone number and pass the MFA session.
var phoneInfoOptions = {
  phoneNumber: phoneNumber,
  session: multiFactorSession
};

傳送驗證訊息到使用者的手機：

Web

import { PhoneAuthProvider } from "firebase/auth";

const phoneAuthProvider = new PhoneAuthProvider(auth);
phoneAuthProvider.verifyPhoneNumber(phoneInfoOptions, recaptchaVerifier)
    .then(function (verificationId) {
        // verificationId will be needed to complete enrollment.
    });

Web

var phoneAuthProvider = new firebase.auth.PhoneAuthProvider();
// Send SMS verification code.
return phoneAuthProvider.verifyPhoneNumber(phoneInfoOptions, recaptchaVerifier)
  .then(function(verificationId) {
    // verificationId will be needed for enrollment completion.
  })

雖然並非必要，但最佳做法是事先告知使用者會收到簡訊，支付一般簡訊費用

如果要求失敗，請重設 reCAPTCHA，然後重複上一個步驟讓使用者再試一次。請注意，verifyPhoneNumber() 會會在擲回錯誤時自動重設 reCAPTCHA，例如 reCAPTCHA 權杖只能使用一次。
Web
```
recaptchaVerifier.clear();
```
Web
```
recaptchaVerifier.clear();
```

讓系統傳送簡訊驗證碼後，要求使用者驗證驗證碼：

Web

// Ask user for the verification code. Then:
const cred = PhoneAuthProvider.credential(verificationId, verificationCode);

Web

// Ask user for the verification code. Then:
var cred = firebase.auth.PhoneAuthProvider.credential(verificationId, verificationCode);

使用 PhoneAuthCredential 初始化 MultiFactorAssertion 物件：

Web

import { PhoneMultiFactorGenerator } from "firebase/auth";

const multiFactorAssertion = PhoneMultiFactorGenerator.assertion(cred);

Web

var multiFactorAssertion = firebase.auth.PhoneMultiFactorGenerator.assertion(cred);

完成註冊程序。您也可以選擇為第二個步驟這項功能適用於具有多項第二項因素的使用者系統會在驗證流程中遮蓋電話號碼 (例如，例如 +1******1234)。

Web

// Complete enrollment. This will update the underlying tokens
// and trigger ID token change listener.
multiFactor(user).enroll(multiFactorAssertion, "My personal phone number");

Web

// Complete enrollment. This will update the underlying tokens
// and trigger ID token change listener.
user.multiFactor.enroll(multiFactorAssertion, 'My personal phone number');

以下程式碼顯示第二重驗證註冊的完整範例：

Web

import {
    multiFactor, PhoneAuthProvider, PhoneMultiFactorGenerator,
    RecaptchaVerifier, getAuth
} from "firebase/auth";

const recaptchaVerifier = new RecaptchaVerifier(getAuth(),
    'recaptcha-container-id', undefined);
multiFactor(user).getSession()
    .then(function (multiFactorSession) {
        // Specify the phone number and pass the MFA session.
        const phoneInfoOptions = {
            phoneNumber: phoneNumber,
            session: multiFactorSession
        };

        const phoneAuthProvider = new PhoneAuthProvider(auth);

        // Send SMS verification code.
        return phoneAuthProvider.verifyPhoneNumber(phoneInfoOptions, recaptchaVerifier);
    }).then(function (verificationId) {
        // Ask user for the verification code. Then:
        const cred = PhoneAuthProvider.credential(verificationId, verificationCode);
        const multiFactorAssertion = PhoneMultiFactorGenerator.assertion(cred);

        // Complete enrollment.
        return multiFactor(user).enroll(multiFactorAssertion, mfaDisplayName);
    });

Web

var recaptchaVerifier = new firebase.auth.RecaptchaVerifier('recaptcha-container-id');
user.multiFactor.getSession().then(function(multiFactorSession) {
  // Specify the phone number and pass the MFA session.
  var phoneInfoOptions = {
    phoneNumber: phoneNumber,
    session: multiFactorSession
  };
  var phoneAuthProvider = new firebase.auth.PhoneAuthProvider();
  // Send SMS verification code.
  return phoneAuthProvider.verifyPhoneNumber(
      phoneInfoOptions, recaptchaVerifier);
})
.then(function(verificationId) {
  // Ask user for the verification code.
  var cred = firebase.auth.PhoneAuthProvider.credential(verificationId, verificationCode);
  var multiFactorAssertion = firebase.auth.PhoneMultiFactorGenerator.assertion(cred);
  // Complete enrollment.
  return user.multiFactor.enroll(multiFactorAssertion, mfaDisplayName);
});

恭喜！您已成功註冊以下項目的第二個驗證方式：而非個別使用者的帳戶

透過次要驗證方式登入使用者

如何透過雙重簡訊驗證功能登入使用者帳戶：

透過第一個步驟登入使用者，然後擷取 auth/multi-factor-auth-required 個錯誤。這項錯誤含有解析器、註冊第二要素的提示，以及基礎工作階段證明使用者已透過第一個因素成功通過驗證。

舉例來說，如果使用者的第一個驗證方法是電子郵件地址和密碼：

Web

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

const auth = getAuth();
signInWithEmailAndPassword(auth, email, password)
    .then(function (userCredential) {
        // User successfully signed in and is not enrolled with a second factor.
    })
    .catch(function (error) {
        if (error.code == 'auth/multi-factor-auth-required') {
            // The user is a multi-factor user. Second factor challenge is required.
            resolver = getMultiFactorResolver(auth, error);
            // ...
        } else if (error.code == 'auth/wrong-password') {
            // Handle other errors such as wrong password.
        }
});

Web

firebase.auth().signInWithEmailAndPassword(email, password)
  .then(function(userCredential) {
    // User successfully signed in and is not enrolled with a second factor.
  })
  .catch(function(error) {
    if (error.code == 'auth/multi-factor-auth-required') {
      // The user is a multi-factor user. Second factor challenge is required.
      resolver = error.resolver;
      // ...
    } else if (error.code == 'auth/wrong-password') {
      // Handle other errors such as wrong password.
    } ...
  });

如果使用者的第一個因素是聯合提供者，例如 OAuth、SAML 或 OIDC，呼叫 signInWithPopup() 後擷取錯誤，或 signInWithRedirect()。

如果使用者已註冊多項次要驗證因素，請詢問他們哪個使用：

Web

// Ask user which second factor to use.
// You can get the masked phone number via resolver.hints[selectedIndex].phoneNumber
// You can get the display name via resolver.hints[selectedIndex].displayName

if (resolver.hints[selectedIndex].factorId ===
    PhoneMultiFactorGenerator.FACTOR_ID) {
    // User selected a phone second factor.
    // ...
} else if (resolver.hints[selectedIndex].factorId ===
           TotpMultiFactorGenerator.FACTOR_ID) {
    // User selected a TOTP second factor.
    // ...
} else {
    // Unsupported second factor.
}

Web

// Ask user which second factor to use.
// You can get the masked phone number via resolver.hints[selectedIndex].phoneNumber
// You can get the display name via resolver.hints[selectedIndex].displayName
if (resolver.hints[selectedIndex].factorId === firebase.auth.PhoneMultiFactorGenerator.FACTOR_ID) {
  // User selected a phone second factor.
  // ...
} else if (resolver.hints[selectedIndex].factorId === firebase.auth.TotpMultiFactorGenerator.FACTOR_ID) {
  // User selected a TOTP second factor.
  // ...
} else {
  // Unsupported second factor.
}

請初始化 reCAPTCHA 驗證器，如上一節所示。如果已設定 RecaptchaVerifier 執行個體，請略過這個步驟：

Web

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

recaptchaVerifier = new RecaptchaVerifier(getAuth(),
    'recaptcha-container-id', undefined);

Web

var recaptchaVerifier = new firebase.auth.RecaptchaVerifier('recaptcha-container-id');

使用使用者的電話號碼和PhoneInfoOptions 多因素工作階段這些值包含在 resolver 中傳遞至 auth/multi-factor-auth-required 錯誤的物件：

Web

const phoneInfoOptions = {
    multiFactorHint: resolver.hints[selectedIndex],
    session: resolver.session
};

Web

var phoneInfoOptions = {
  multiFactorHint: resolver.hints[selectedIndex],
  session: resolver.session
};

傳送驗證訊息到使用者的手機：

Web

// Send SMS verification code.
const phoneAuthProvider = new PhoneAuthProvider(auth);
phoneAuthProvider.verifyPhoneNumber(phoneInfoOptions, recaptchaVerifier)
    .then(function (verificationId) {
        // verificationId will be needed for sign-in completion.
    });

Web

var phoneAuthProvider = new firebase.auth.PhoneAuthProvider();
// Send SMS verification code.
return phoneAuthProvider.verifyPhoneNumber(phoneInfoOptions, recaptchaVerifier)
  .then(function(verificationId) {
    // verificationId will be needed for sign-in completion.
  })

如果要求失敗，請重設 reCAPTCHA，然後重複上一個步驟以便使用者再試一次：
Web
```
recaptchaVerifier.clear();
```
Web
```
recaptchaVerifier.clear();
```

讓系統傳送簡訊驗證碼後，要求使用者驗證驗證碼：

Web

const cred = PhoneAuthProvider.credential(verificationId, verificationCode);

Web

// Ask user for the verification code. Then:
var cred = firebase.auth.PhoneAuthProvider.credential(verificationId, verificationCode);

使用 PhoneAuthCredential 初始化 MultiFactorAssertion 物件：

Web

const multiFactorAssertion = PhoneMultiFactorGenerator.assertion(cred);

Web

var multiFactorAssertion = firebase.auth.PhoneMultiFactorGenerator.assertion(cred);

請呼叫 resolver.resolveSignIn() 完成次要驗證。接著，您可以存取原始登入結果，包括標準供應商專屬資料和驗證憑證：

Web

// Complete sign-in. This will also trigger the Auth state listeners.
resolver.resolveSignIn(multiFactorAssertion)
    .then(function (userCredential) {
        // userCredential will also contain the user, additionalUserInfo, optional
        // credential (null for email/password) associated with the first factor sign-in.

        // For example, if the user signed in with Google as a first factor,
        // userCredential.additionalUserInfo will contain data related to Google
        // provider that the user signed in with.
        // - user.credential contains the Google OAuth credential.
        // - user.credential.accessToken contains the Google OAuth access token.
        // - user.credential.idToken contains the Google OAuth ID token.
    });

Web

// Complete sign-in. This will also trigger the Auth state listeners.
resolver.resolveSignIn(multiFactorAssertion)
  .then(function(userCredential) {
    // userCredential will also contain the user, additionalUserInfo, optional
    // credential (null for email/password) associated with the first factor sign-in.
    // For example, if the user signed in with Google as a first factor,
    // userCredential.additionalUserInfo will contain data related to Google provider that
    // the user signed in with.
    // user.credential contains the Google OAuth credential.
    // user.credential.accessToken contains the Google OAuth access token.
    // user.credential.idToken contains the Google OAuth ID token.
  });

以下程式碼是多因素使用者登入的完整範例：

Web

import {
    getAuth,
    getMultiFactorResolver,
    PhoneAuthProvider,
    PhoneMultiFactorGenerator,
    RecaptchaVerifier,
    signInWithEmailAndPassword
} from "firebase/auth";

const recaptchaVerifier = new RecaptchaVerifier(getAuth(),
    'recaptcha-container-id', undefined);

const auth = getAuth();
signInWithEmailAndPassword(auth, email, password)
    .then(function (userCredential) {
        // User is not enrolled with a second factor and is successfully
        // signed in.
        // ...
    })
    .catch(function (error) {
        if (error.code == 'auth/multi-factor-auth-required') {
            const resolver = getMultiFactorResolver(auth, error);
            // Ask user which second factor to use.
            if (resolver.hints[selectedIndex].factorId ===
                PhoneMultiFactorGenerator.FACTOR_ID) {
                const phoneInfoOptions = {
                    multiFactorHint: resolver.hints[selectedIndex],
                    session: resolver.session
                };
                const phoneAuthProvider = new PhoneAuthProvider(auth);
                // Send SMS verification code
                return phoneAuthProvider.verifyPhoneNumber(phoneInfoOptions, recaptchaVerifier)
                    .then(function (verificationId) {
                        // Ask user for the SMS verification code. Then:
                        const cred = PhoneAuthProvider.credential(
                            verificationId, verificationCode);
                        const multiFactorAssertion =
                            PhoneMultiFactorGenerator.assertion(cred);
                        // Complete sign-in.
                        return resolver.resolveSignIn(multiFactorAssertion)
                    })
                    .then(function (userCredential) {
                        // User successfully signed in with the second factor phone number.
                    });
            } else if (resolver.hints[selectedIndex].factorId ===
                       TotpMultiFactorGenerator.FACTOR_ID) {
                // Handle TOTP MFA.
                // ...
            } else {
                // Unsupported second factor.
            }
        } else if (error.code == 'auth/wrong-password') {
            // Handle other errors such as wrong password.
        }
    });

Web

var resolver;
firebase.auth().signInWithEmailAndPassword(email, password)
  .then(function(userCredential) {
    // User is not enrolled with a second factor and is successfully signed in.
    // ...
  })
  .catch(function(error) {
    if (error.code == 'auth/multi-factor-auth-required') {
      resolver = error.resolver;
      // Ask user which second factor to use.
      if (resolver.hints[selectedIndex].factorId ===
          firebase.auth.PhoneMultiFactorGenerator.FACTOR_ID) {
        var phoneInfoOptions = {
          multiFactorHint: resolver.hints[selectedIndex],
          session: resolver.session
        };
        var phoneAuthProvider = new firebase.auth.PhoneAuthProvider();
        // Send SMS verification code
        return phoneAuthProvider.verifyPhoneNumber(phoneInfoOptions, recaptchaVerifier)
          .then(function(verificationId) {
            // Ask user for the SMS verification code.
            var cred = firebase.auth.PhoneAuthProvider.credential(
                verificationId, verificationCode);
            var multiFactorAssertion =
                firebase.auth.PhoneMultiFactorGenerator.assertion(cred);
            // Complete sign-in.
            return resolver.resolveSignIn(multiFactorAssertion)
          })
          .then(function(userCredential) {
            // User successfully signed in with the second factor phone number.
          });
      } else if (resolver.hints[selectedIndex].factorId ===
        firebase.auth.TotpMultiFactorGenerator.FACTOR_ID) {
        // Handle TOTP MFA.
        // ...
      } else {
        // Unsupported second factor.
      }
    } else if (error.code == 'auth/wrong-password') {
      // Handle other errors such as wrong password.
    } ...
  });

恭喜！您已成功透過多重要素登入使用者驗證。

後續步驟

管理多重驗證使用者透過程式利用 Admin SDK。