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

1. 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。

2. 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

3. 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)：

1. 在 Google Cloud 控制台中，選取要使用的用戶群。

2. 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

1. 開啟「驗證 >登入方式 Firebase控制台中的頁面。

2. 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

3. 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：

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();
    }
});

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：

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.
        // ...
      }
    }
);

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：

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

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：

1. 重新驗證使用者。

2. 請使用者輸入電話號碼。

3. 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');
   

4. 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) {
     // ...
   })
   

5. 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
   };
   

6. 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

7. 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();
   

8. 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);
   

9. 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);
   

10. 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：

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);
    });

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：

1. 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, signInWithEmailAndPassword, 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()。

2. 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.
   }
   

3. 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');
   

4. 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
   };
   

5. 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.
     })
   

6. 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();
   

7. 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);
   

8. 使用 PhoneAuthCredential 初始化 MultiFactorAssertion 物件：

   Web

   const multiFactorAssertion = PhoneMultiFactorGenerator.assertion(cred);
   

   Web

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

9. 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：

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.
        }
    });

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。