将多重身份验证添加到您的 Android 应用程序

如果您已使用 Identity Platform 升级到 Firebase 身份验证，则可以将 SMS 多重身份验证添加到您的 Android 应用。

多因素身份验证可提高应用程序的安全性。虽然攻击者经常破坏密码和社交帐户，但拦截短信更加困难。

在你开始之前

注意： Android 不支持对多个租户使用多重身份验证。

1. 启用至少一个支持多重身份验证的提供程序。除电话验证、匿名验证和 Apple Game Center 外，每个提供商都支持 MFA。

2. 确保您的应用正在验证用户电子邮件。 MFA 需要电子邮件验证。这可以防止恶意行为者使用他们不拥有的电子邮件注册服务，然后通过添加第二个因素锁定真正的所有者。

3. 在 Firebase 控制台中注册您应用的 SHA-1 哈希（您的更改将自动转移到 Google Cloud Firebase）。

   1. 按照Authenticating your client中的步骤获取应用的 SHA-1 哈希。

   2. 打开Firebase 控制台。

   3. 导航到项目设置。

   4. 在您的应用下，单击 Android 图标。

   5. 按照指导步骤添加您的 SHA-1 哈希。

启用多重身份验证

1. 打开 Firebase 控制台的身份验证 > 登录方法页面。

2. 在高级部分，启用SMS Multi-factor Authentication 。

   您还应该输入用于测试应用程序的电话号码。虽然可选，但强烈建议注册测试电话号码以避免在开发过程中受到限制。

3. 如果您尚未授权应用的域，请将其添加到 Firebase 控制台的“身份验证”>“设置”页面上的允许列表中。

选择注册模式

您可以选择您的应用程序是否需要多重身份验证，以及注册用户的方式和时间。一些常见的模式包括：

• 注册用户的第二个因素作为注册的一部分。如果您的应用需要对所有用户进行多重身份验证，请使用此方法。

• 提供可跳过的选项以在注册期间注册第二个因素。想要鼓励但不要求多因素身份验证的应用程序可能更喜欢这种方法。

• 提供从用户帐户或配置文件管理页面添加第二个因素的能力，而不是注册屏幕。这最大限度地减少了注册过程中的摩擦，同时仍然为安全敏感的用户提供多因素身份验证。

• 当用户想要访问具有更高安全要求的功能时，需要逐步添加第二个因素。

注册第二个因素

为用户注册一个新的次要因素：

1. 重新验证用户。

2. 要求用户输入他们的电话号码。

   注意： Google 存储并使用电话号码来改进所有 Google 服务的垃圾邮件和滥用预防。确保在将用户的电话号码发送到 Firebase 之前获得用户的适当同意。

3. 为用户获取多因素会话：

   Kotlin+KTX

   user.multiFactor.session.addOnCompleteListener { task ->
       if (task.isSuccessful) {
           val multiFactorSession: MultiFactorSession? = task.result
       }
   }
   

   Java

   user.getMultiFactor().getSession()
     .addOnCompleteListener(
         new OnCompleteListener<MultiFactorSession>() {
         @Override
         public void onComplete(@NonNull Task<MultiFactorSession> task) {
           if (task.isSuccessful()) {
             MultiFactorSession multiFactorSession = task.getResult();
           }
         }
         });
   

4. 构建一个OnVerificationStateChangedCallbacks对象来处理验证过程中的不同事件：

   Kotlin+KTX

   val callbacks = object : OnVerificationStateChangedCallbacks() {
       override fun onVerificationCompleted(credential: PhoneAuthCredential) {
           // This callback will be invoked in two situations:
           // 1) Instant verification. In some cases, the phone number can be
           //    instantly verified without needing to send or enter a verification
           //    code. You can disable this feature by calling
           //    PhoneAuthOptions.builder#requireSmsValidation(true) when building
           //    the options to pass to PhoneAuthProvider#verifyPhoneNumber().
           // 2) Auto-retrieval. On some devices, Google Play services can
           //    automatically detect the incoming verification SMS and perform
           //    verification without user action.
           [e-mail] = credential
       }
   
       override fun onVerificationFailed(e: FirebaseException) {
           // This callback is invoked in response to invalid requests for
           // verification, like an incorrect phone number.
           if (e is FirebaseAuthInvalidCredentialsException) {
               // Invalid request
               // ...
           } else if (e is FirebaseTooManyRequestsException) {
               // The SMS quota for the project has been exceeded
               // ...
           }
           // Show a message and update the UI
           // ...
       }
   
       override fun onCodeSent(
           verificationId: String, forceResendingToken: ForceResendingToken
       ) {
           // The SMS verification code has been sent to the provided phone number.
           // We now need to ask the user to enter the code and then construct a
           // credential by combining the code with a verification ID.
           // Save the verification ID and resending token for later use.
           [e-mail] = verificationId
           [e-mail] = forceResendingToken
           // ...
       }
   }
   

   Java

   OnVerificationStateChangedCallbacks callbacks =
   new OnVerificationStateChangedCallbacks() {
     @Override
     public void onVerificationCompleted(PhoneAuthCredential credential) {
       // This callback will be invoked in two situations:
       // 1) Instant verification. In some cases, the phone number can be
       //    instantly verified without needing to send or enter a verification
       //    code. You can disable this feature by calling
       //    PhoneAuthOptions.builder#requireSmsValidation(true) when building
       //    the options to pass to PhoneAuthProvider#verifyPhoneNumber().
       // 2) Auto-retrieval. On some devices, Google Play services can
       //    automatically detect the incoming verification SMS and perform
       //    verification without user action.
       this.credential = credential;
     }
     @Override
     public void onVerificationFailed(FirebaseException e) {
       // This callback is invoked in response to invalid requests for
       // verification, like an incorrect phone number.
       if (e instanceof FirebaseAuthInvalidCredentialsException) {
       // Invalid request
       // ...
       } else if (e instanceof FirebaseTooManyRequestsException) {
       // The SMS quota for the project has been exceeded
       // ...
       }
       // Show a message and update the UI
       // ...
     }
     @Override
     public void onCodeSent(
       String verificationId, PhoneAuthProvider.ForceResendingToken token) {
       // The SMS verification code has been sent to the provided phone number.
       // We now need to ask the user to enter the code and then construct a
       // credential by combining the code with a verification ID.
       // Save the verification ID and resending token for later use.
       this.verificationId = verificationId;
       this.forceResendingToken = token;
       // ...
     }
   };
   

5. 使用用户的电话号码、多因素会话和您的回调初始化一个PhoneInfoOptions对象：

   Kotlin+KTX

   val phoneAuthOptions = PhoneAuthOptions.newBuilder()
       .setPhoneNumber(phoneNumber)
       .setTimeout(30L, TimeUnit.SECONDS)
       .setMultiFactorSession(MultiFactorSession)
       .setCallbacks(callbacks)
       .build()
   

   Java

   PhoneAuthOptions phoneAuthOptions =
     PhoneAuthOptions.newBuilder()
         .setPhoneNumber(phoneNumber)
         .setTimeout(30L, TimeUnit.SECONDS)
         .setMultiFactorSession(multiFactorSession)
         .setCallbacks(callbacks)
         .build();
   

   默认情况下，启用即时验证。要禁用它，请添加对requireSmsValidation(true)的调用。

6. 向用户手机发送验证信息：

   Kotlin+KTX

   PhoneAuthProvider.verifyPhoneNumber(phoneAuthOptions)
   

   Java

   PhoneAuthProvider.verifyPhoneNumber(phoneAuthOptions);
   

   虽然不是必需的，但最好提前通知用户他们将收到 SMS 消息，并且适用标准费率。

7. 发送 SMS 代码后，要求用户验证代码：

   Kotlin+KTX

   // Ask user for the verification code.
   val credential = PhoneAuthProvider.getCredential(verificationId, verificationCode)
   

   Java

   // Ask user for the verification code.
   PhoneAuthCredential credential
     = PhoneAuthProvider.getCredential(verificationId, verificationCode);
   

8. 使用PhoneAuthCredential初始化MultiFactorAssertion对象：

   Kotlin+KTX

   val multiFactorAssertion
     = PhoneMultiFactorGenerator.getAssertion(credential)
   

   Java

   MultiFactorAssertion multiFactorAssertion
     = PhoneMultiFactorGenerator.getAssertion(credential);
   

9. 完成报名。或者，您可以指定第二个因素的显示名称。这对于具有多个第二因素的用户很有用，因为电话号码在身份验证流程中被屏蔽（例如，+1******1234）。

   Kotlin+KTX

   // Complete enrollment. This will update the underlying tokens
   // and trigger ID token change listener.
   FirebaseAuth.getInstance()
       .currentUser
       ?.multiFactor
       ?.enroll(multiFactorAssertion, "My personal phone number")
       ?.addOnCompleteListener {
           // ...
       }
   

   Java

   // Complete enrollment. This will update the underlying tokens
   // and trigger ID token change listener.
   FirebaseAuth.getInstance()
     .getCurrentUser()
     .getMultiFactor()
     .enroll(multiFactorAssertion, "My personal phone number")
     .addOnCompleteListener(
         new OnCompleteListener<Void>() {
         @Override
         public void onComplete(@NonNull Task<Void> task) {
           // ...
         }
         });
   

下面的代码显示了注册第二个因素的完整示例：

Kotlin+KTX

val multiFactorAssertion = PhoneMultiFactorGenerator.getAssertion(credential)
user.multiFactor.session
    .addOnCompleteListener { task ->
        if (task.isSuccessful) {
            val multiFactorSession = task.result
            val phoneAuthOptions = PhoneAuthOptions.newBuilder()
                .setPhoneNumber(phoneNumber)
                .setTimeout(30L, TimeUnit.SECONDS)
                .setMultiFactorSession(multiFactorSession)
                .setCallbacks(callbacks)
                .build()
            // Send SMS verification code.
            PhoneAuthProvider.verifyPhoneNumber(phoneAuthOptions)
        }
    }

// Ask user for the verification code.
val credential = PhoneAuthProvider.getCredential(verificationId, verificationCode)

val multiFactorAssertion = PhoneMultiFactorGenerator.getAssertion(credential)

// Complete enrollment.
FirebaseAuth.getInstance()
    .currentUser
    ?.multiFactor
    ?.enroll(multiFactorAssertion, "My personal phone number")
    ?.addOnCompleteListener {
        // ...
    }

Java

MultiFactorAssertion multiFactorAssertion = PhoneMultiFactorGenerator.getAssertion(credential);
user.getMultiFactor().getSession()
  .addOnCompleteListener(
      new OnCompleteListener<MultiFactorSession>() {
      @Override
      public void onComplete(@NonNull Task<MultiFactorSession> task) {
        if (task.isSuccessful()) {
          MultiFactorSession multiFactorSession = task.getResult();
          PhoneAuthOptions phoneAuthOptions =
            PhoneAuthOptions.newBuilder()
                .setPhoneNumber(phoneNumber)
                .setTimeout(30L, TimeUnit.SECONDS)
                .setMultiFactorSession(multiFactorSession)
                .setCallbacks(callbacks)
                .build();
          // Send SMS verification code.
          PhoneAuthProvider.verifyPhoneNumber(phoneAuthOptions);
        }
      }
      });

// Ask user for the verification code.
PhoneAuthCredential credential =
  PhoneAuthProvider.getCredential(verificationId, verificationCode);

MultiFactorAssertion multiFactorAssertion = PhoneMultiFactorGenerator.getAssertion(credential);
// Complete enrollment.
FirebaseAuth.getInstance()
  .getCurrentUser()
  .getMultiFactor()
  .enroll(multiFactorAssertion, "My personal phone number")
  .addOnCompleteListener(
      new OnCompleteListener<Void>() {
      @Override
      public void onComplete(@NonNull Task<Void> task) {
        // ...
      }
      });

恭喜！您成功为用户注册了第二个身份验证因素。

重要提示：您应该强烈鼓励您的用户注册超过一秒的因素以进行帐户恢复。如果用户只注册了一个第二个因素，后来又失去了访问权限，他们将被锁定在他们的帐户之外。

使用第二个因素让用户登录

要使用双因素 SMS 验证登录用户：

1. 使用他们的第一个因素登录用户，然后捕获FirebaseAuthMultiFactorException异常。此错误包含一个解析程序，您可以使用它来获取用户注册的第二个因素。它还包含一个基础会话，证明用户成功通过他们的第一个因素进行身份验证。

   例如，如果用户的第一个因素是电子邮件和密码：

   Kotlin+KTX

   FirebaseAuth.getInstance()
       .signInWithEmailAndPassword(email, password)
       .addOnCompleteListener(
           OnCompleteListener { task ->
               if (task.isSuccessful) {
                   // User is not enrolled with a second factor and is successfully
                   // signed in.
                   // ...
                   return@OnCompleteListener
               }
               if (task.exception is FirebaseAuthMultiFactorException) {
                   // The user is a multi-factor user. Second factor challenge is
                   // required.
                   val multiFactorResolver =
                       (task.exception as FirebaseAuthMultiFactorException).resolver
                   // ...
               } else {
                   // Handle other errors, such as wrong password.
               }
           })
   

   Java

   FirebaseAuth.getInstance()
     .signInWithEmailAndPassword(email, password)
     .addOnCompleteListener(
         new OnCompleteListener<AuthResult>() {
         @Override
         public void onComplete(@NonNull Task<AuthResult> task) {
           if (task.isSuccessful()) {
             // User is not enrolled with a second factor and is successfully
             // signed in.
             // ...
             return;
           }
           if (task.getException() instanceof FirebaseAuthMultiFactorException) {
             // The user is a multi-factor user. Second factor challenge is
             // required.
             MultiFactorResolver multiFactorResolver = task.getException().getResolver();
             // ...
           } else {
             // Handle other errors such as wrong password.
           }
         }
         });
   

   如果用户的第一个因素是联合提供程序，例如 OAuth，则在调用startActivityForSignInWithProvider()后捕获错误。

2. 如果用户注册了多个次要因素，请询问他们使用哪一个：

   Kotlin+KTX

   // Ask user which second factor to use.
   // You can get the list of enrolled second factors using
   //   multiFactorResolver.hints
   
   // Check the selected factor:
   if (multiFactorResolver.hints[selectedIndex].factorId
       === PhoneMultiFactorGenerator.FACTOR_ID
   ) {
       // User selected a phone second factor.
       val selectedHint = 
           multiFactorResolver.hints[selectedIndex] as PhoneMultiFactorInfo
   } else {
       // Unsupported second factor.
       // Note that only phone second factors are currently supported.
   }
   

   Java

   // Ask user which second factor to use.
   // You can get the masked phone number using
   // resolver.getHints().get(selectedIndex).getPhoneNumber()
   // You can get the display name using
   // resolver.getHints().get(selectedIndex).getDisplayName()
   if (resolver.getHints().get(selectedIndex).getFactorId()
     == PhoneMultiFactorGenerator.FACTOR_ID) {
   // User selected a phone second factor.
   MultiFactorInfo selectedHint =
     multiFactorResolver.getHints().get(selectedIndex);
   } else {
   // Unsupported second factor.
   // Note that only phone second factors are currently supported.
   }
   

3. 使用提示和多因素会话初始化PhoneAuthOptions对象。这些值包含在附加到FirebaseAuthMultiFactorException的解析器中。

   Kotlin+KTX

   val phoneAuthOptions = PhoneAuthOptions.newBuilder()
       .setMultiFactorHint(selectedHint)
       .setTimeout(30L, TimeUnit.SECONDS)
       .setMultiFactorSession(multiFactorResolver.session)
       .setCallbacks(callbacks) // Optionally disable instant verification.
       // .requireSmsValidation(true)
       .build()
   

   Java

   PhoneAuthOptions phoneAuthOptions =
     PhoneAuthOptions.newBuilder()
         .setMultiFactorHint(selectedHint)
         .setTimeout(30L, TimeUnit.SECONDS)
         .setMultiFactorSession(multiFactorResolver.getSession())
         .setCallbacks(callbacks)
         // Optionally disable instant verification.
         // .requireSmsValidation(true)
         .build();
   

4. 向用户手机发送验证信息：

   Kotlin+KTX

   // Send SMS verification code
   PhoneAuthProvider.verifyPhoneNumber(phoneAuthOptions)
   

   Java

   // Send SMS verification code
   PhoneAuthProvider.verifyPhoneNumber(phoneAuthOptions);
   

5. 发送 SMS 代码后，要求用户验证代码：

   Kotlin+KTX

   // Ask user for the verification code. Then, pass it to getCredential:
   val credential =
       PhoneAuthProvider.getCredential(verificationId, verificationCode)
   

   Java

   // Ask user for the verification code. Then, pass it to getCredential:
   PhoneAuthCredential credential
       = PhoneAuthProvider.getCredential(verificationId, verificationCode);
   

6. 使用PhoneAuthCredential初始化MultiFactorAssertion对象：

   Kotlin+KTX

   val multiFactorAssertion = PhoneMultiFactorGenerator.getAssertion(credential)
   

   Java

   MultiFactorAssertion multiFactorAssertion
       = PhoneMultiFactorGenerator.getAssertion(credential);
   

7. 调用resolver.resolveSignIn()完成二次认证。然后，您可以访问原始登录结果，其中包括标准的提供商特定数据和身份验证凭据：

   Kotlin+KTX

   multiFactorResolver
       .resolveSignIn(multiFactorAssertion)
       .addOnCompleteListener { task ->
           if (task.isSuccessful) {
               val authResult = task.result
               // AuthResult will also contain the user, additionalUserInfo,
               // and an 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, authResult.getAdditionalUserInfo() will contain data
               // related to Google provider that the user signed in with;
               // authResult.getCredential() will contain the Google OAuth
               //   credential;
               // authResult.getCredential().getAccessToken() will contain the
               //   Google OAuth access token;
               // authResult.getCredential().getIdToken() contains the Google
               //   OAuth ID token.
           }
       }
   

   Java

   multiFactorResolver
     .resolveSignIn(multiFactorAssertion)
     .addOnCompleteListener(
         new OnCompleteListener<AuthResult>() {
         @Override
         public void onComplete(@NonNull Task<AuthResult> task) {
           if (task.isSuccessful()) {
             AuthResult authResult = task.getResult();
             // AuthResult will also contain the user, additionalUserInfo,
             // and an 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, authResult.getAdditionalUserInfo() will contain data
             // related to Google provider that the user signed in with.
             // authResult.getCredential() will contain the Google OAuth
             // credential.
             // authResult.getCredential().getAccessToken() will contain the
             // Google OAuth access token.
             // authResult.getCredential().getIdToken() contains the Google
             // OAuth ID token.
           }
         }
         });
   

下面的代码显示了一个多因素用户登录的完整示例：

Kotlin+KTX

FirebaseAuth.getInstance()
    .signInWithEmailAndPassword(email, password)
    .addOnCompleteListener { task ->
        if (task.isSuccessful) {
            // User is not enrolled with a second factor and is successfully
            // signed in.
            // ...
            return@addOnCompleteListener
        }
        if (task.exception is FirebaseAuthMultiFactorException) {
            val multiFactorResolver =
                (task.exception as FirebaseAuthMultiFactorException).resolver

            // Ask user which second factor to use. Then, get
            // the selected hint:
            val selectedHint =
                multiFactorResolver.hints[selectedIndex] as PhoneMultiFactorInfo

            // Send the SMS verification code.
            PhoneAuthProvider.verifyPhoneNumber(
                PhoneAuthOptions.newBuilder()
                    .setActivity(this)
                    .setMultiFactorSession(multiFactorResolver.session)
                    .setMultiFactorHint(selectedHint)
                    .setCallbacks(generateCallbacks())
                    .setTimeout(30L, TimeUnit.SECONDS)
                    .build()
            )

            // Ask user for the SMS verification code, then use it to get
            // a PhoneAuthCredential:
            val credential =
                PhoneAuthProvider.getCredential(verificationId, verificationCode)

            // Initialize a MultiFactorAssertion object with the
            // PhoneAuthCredential.
            val multiFactorAssertion: MultiFactorAssertion =
                PhoneMultiFactorGenerator.getAssertion(credential)

            // Complete sign-in.
            multiFactorResolver
                .resolveSignIn(multiFactorAssertion)
                .addOnCompleteListener { task ->
                    if (task.isSuccessful) {
                        // User successfully signed in with the
                        // second factor phone number.
                    }
                    // ...
                }
        } else {
            // Handle other errors such as wrong password.
        }
    }

Java

FirebaseAuth.getInstance()
  .signInWithEmailAndPassword(email, password)
  .addOnCompleteListener(
      new OnCompleteListener<AuthResult>() {
      @Override
      public void onComplete(@NonNull Task<AuthResult> task) {
        if (task.isSuccessful()) {
          // User is not enrolled with a second factor and is successfully
          // signed in.
          // ...
          return;
        }
        if (task.getException() instanceof FirebaseAuthMultiFactorException) {
          FirebaseAuthMultiFactorException e =
            (FirebaseAuthMultiFactorException) task.getException();

          MultiFactorResolver multiFactorResolver = e.getResolver();

          // Ask user which second factor to use.
          MultiFactorInfo selectedHint =
            multiFactorResolver.getHints().get(selectedIndex);

          // Send the SMS verification code.
          PhoneAuthProvider.verifyPhoneNumber(
            PhoneAuthOptions.newBuilder()
                .setActivity(this)
                .setMultiFactorSession(multiFactorResolver.getSession())
                .setMultiFactorHint(selectedHint)
                .setCallbacks(generateCallbacks())
                .setTimeout(30L, TimeUnit.SECONDS)
                .build());

          // Ask user for the SMS verification code.
          PhoneAuthCredential credential =
            PhoneAuthProvider.getCredential(verificationId, verificationCode);

          // Initialize a MultiFactorAssertion object with the
          // PhoneAuthCredential.
          MultiFactorAssertion multiFactorAssertion =
            PhoneMultiFactorGenerator.getAssertion(credential);

          // Complete sign-in.
          multiFactorResolver
            .resolveSignIn(multiFactorAssertion)
            .addOnCompleteListener(
                new OnCompleteListener<AuthResult>() {
                  @Override
                  public void onComplete(@NonNull Task<AuthResult> task) {
                  if (task.isSuccessful()) {
                    // User successfully signed in with the
                    // second factor phone number.
                  }
                  // ...
                  }
                });
        } else {
          // Handle other errors such as wrong password.
        }
      }
      });

恭喜！您使用多重身份验证成功登录了用户。

下一步是什么

• 使用 Admin SDK 以编程方式管理多因素用户。