// Prompt user to re-authenticate to Yahoo.provider_data.custom_parameters["prompt"]="login";// Localize to French.provider_data.custom_parameters["language"]="fr";
可选：指定您希望向身份验证提供方申请的 profile 和 email 之外的 OAuth 2.0 范围。如果您的应用需要通过 Yahoo API 访问用户私人数据，您需要在 Yahoo 开发者控制台的 API 权限下申请 Yahoo API 权限。申请的 OAuth 范围必须与应用的 API 权限中预配置的范围完全匹配。例如，如果您申请了对用户通讯录的读写权限，并已在应用的 API 权限中预配置相应权限，则必须传递 sdct-w 而不是只读 OAuth 范围 sdct-r。否则将导致流程失败，并向最终用户显示错误消息。
// Request access to Yahoo Mail API.provider_data.scopes.push_back("mail-r");// This must be preconfigured in the app's API permissions.provider_data.scopes.push_back("sdct-w");
firebase::auth::Useruser=auth->current_user();if(user.is_valid()){std::stringname=user.display_name();std::stringemail=user.email();std::stringphoto_url=user.photo_url();// The user's ID, unique to the Firebase project.// Do NOT use this value to authenticate with your backend server,// if you have one. Use firebase::auth::User::Token() instead.std::stringuid=user.uid();}
[[["易于理解","easyToUnderstand","thumb-up"],["解决了我的问题","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["没有我需要的信息","missingTheInformationINeed","thumb-down"],["太复杂/步骤太多","tooComplicatedTooManySteps","thumb-down"],["内容需要更新","outOfDate","thumb-down"],["翻译问题","translationIssue","thumb-down"],["示例/代码问题","samplesCodeIssue","thumb-down"],["其他","otherDown","thumb-down"]],["最后更新时间 (UTC)：2025-08-16。"],[],[],null,["You can let your users authenticate with Firebase using OAuth providers like\nYahoo by integrating web-based generic OAuth Login into your app using the\nFirebase SDK to carry out the end to end sign-in flow. Since this flow requires\nthe use of the phone-based Firebase SDKs, it is only supported on Android and\nApple platforms.\n\nBefore you begin\n\n1. [Add Firebase to your C++ project](/docs/cpp/setup#note_select_platform).\n2. In the [Firebase console](//console.firebase.google.com/), open the **Auth** section.\n3. On the **Sign in method** tab, enable the **Yahoo** provider.\n4. Add the **Client ID** and **Client Secret** from that provider's developer console to the provider configuration:\n 1. To register a Yahoo OAuth client, follow the Yahoo developer\n documentation on [registering a web application with Yahoo](https://developer.yahoo.com/oauth2/guide/openid_connect/getting_started.html).\n\n Be sure to select the two OpenID Connect API permissions:\n `profile` and `email`.\n 2. When registering apps with these providers, be sure to register the `*.firebaseapp.com` domain for your project as the redirect domain for your app.\n5. Click **Save**.\n\nAccess the `firebase::auth::Auth` class The `Auth` class is the gateway for all API calls.\n\n1. Add the Auth and App header files: \n\n ```c++\n #include \"firebase/app.h\"\n #include \"firebase/auth.h\"\n ```\n2. In your initialization code, create a [`firebase::App`](/docs/reference/cpp/class/firebase/app) class. \n\n ```c++\n #if defined(__ANDROID__)\n firebase::App* app =\n firebase::App::Create(firebase::AppOptions(), my_jni_env, my_activity);\n #else\n firebase::App* app = firebase::App::Create(firebase::AppOptions());\n #endif // defined(__ANDROID__)\n ```\n3. Acquire the `firebase::auth::Auth` class for your `firebase::App`. There is a one-to-one mapping between `App` and `Auth`. \n\n ```c++\n firebase::auth::Auth* auth = firebase::auth::Auth::GetAuth(app);\n ```\n\nHandle the sign-in flow with the Firebase SDK\n\nTo handle the sign-in flow with the Firebase SDK, follow these steps:\n\n1. Construct an instance of a `FederatedOAuthProviderData` configured with\n the provider ID appropriate for Yahoo.\n\n firebase::auth::FederatedOAuthProviderData\n provider_data(firebase::auth::YahooAuthProvider::kProviderId);\n\n2. **Optional**: Specify additional custom OAuth parameters that you want to\n send with the OAuth request.\n\n // Prompt user to re-authenticate to Yahoo.\n provider_data.custom_parameters[\"prompt\"] = \"login\";\n\n // Localize to French.\n provider_data.custom_parameters[\"language\"] = \"fr\";\n\n For the parameters Yahoo supports, see the\n [Yahoo OAuth documentation](https://developer.yahoo.com/oauth2/guide/openid_connect/getting_started.html).\n Note that you can't pass Firebase-required parameters with\n `custom_parameters()`. These parameters are **client_id** ,\n **redirect_uri** , **response_type** , **scope** and **state**.\n3. **Optional** : Specify additional OAuth 2.0 scopes beyond `profile` and\n `email` that you want to request from the authentication provider. If your\n application requires access to private user data from Yahoo APIs, you'll\n need to request permissions to Yahoo APIs under **API Permissions** in the\n Yahoo developer console. Requested OAuth scopes must be exact matches to the\n preconfigured ones in the app's API permissions. For example if, read/write\n access is requested to user contacts and preconfigured in the app's API\n permissions, `sdct-w` has to be passed instead of the readonly OAuth scope\n `sdct-r`. Otherwise,the flow will fail and an error would be shown to the\n end user.\n\n // Request access to Yahoo Mail API.\n provider_data.scopes.push_back(\"mail-r\");\n // This must be preconfigured in the app's API permissions.\n provider_data.scopes.push_back(\"sdct-w\");\n\n To learn more, refer to the\n [Yahoo scopes documentation](https://developer.yahoo.com/oauth2/guide/yahoo_scopes/).\n4. Once your provider data has been configured, use it to create a\n FederatedOAuthProvider.\n\n // Construct a FederatedOAuthProvider for use in Auth methods.\n firebase::auth::FederatedOAuthProvider provider(provider_data);\n\n5. Authenticate with Firebase using the Auth provider object. Note that unlike\n other FirebaseAuth operations, this will take control of your UI by popping\n up a web view in which the user can enter their credentials.\n\n To start the sign in flow, call `SignInWithProvider`: \n\n firebase::Future\u003cfirebase::auth::AuthResult\u003e result =\n auth-\u003eSignInWithProvider(provider_data);\n\n Your application may then wait or [register a callback on the Future](#register_callback_on_future).\n6. While the above examples focus on sign-in flows, you also have the\n ability to link a Yahoo provider to an existing user using\n `LinkWithProvider`. For example, you can link multiple\n providers to the same user allowing them to sign in with either.\n\n firebase::Future\u003cfirebase::auth::AuthResult\u003e result = user.LinkWithProvider(provider_data);\n\n7. The same pattern can be used with `ReauthenticateWithProvider` which can be\n used to retrieve fresh credentials for sensitive operations that require\n recent login.\n\n firebase::Future\u003cfirebase::auth::AuthResult\u003e result =\n user.ReauthenticateWithProvider(provider_data);\n\n Your application may then wait or [register a callback on\n the Future](#register_callback_on_future).\n\nAdvanced: Handle the sign-in flow manually\n\nUnlike other OAuth providers supported by Firebase such as Google, Facebook,\nand Twitter, where sign-in can directly be achieved with OAuth access token\nbased credentials, Firebase Auth does not support the same capability for\nproviders such as Yahoo due to the inability of the Firebase\nAuth server to verify the audience of Yahoo OAuth access tokens.\nThis is a critical security requirement and could expose applications and\nwebsites to replay attacks where a Yahoo OAuth access token obtained for\none project (attacker) can be used to sign in to another project (victim).\nInstead, Firebase Auth offers the ability to handle the entire OAuth flow and\nthe authorization code exchange using the OAuth client ID and secret\nconfigured in the Firebase Console. As the authorization code can only be used\nin conjunction with a specific client ID/secret, an authorization code\nobtained for one project cannot be used with another.\n\nIf these providers are required to be used in unsupported environments, a\nthird party OAuth library and\n[Firebase custom authentication](../admin/create-custom-tokens)\nwould need to be used. The former is needed to authenticate with the provider\nand the latter to exchange the provider's credential for a custom token.\n\nNext steps\n\nAfter a user signs in for the first time, a new user account is created and\nlinked to the credentials---that is, the user name and password, phone\nnumber, or auth provider information---the user signed in with. This new\naccount is stored as part of your Firebase project, and can be used to identify\na user across every app in your project, regardless of how the user signs in.\n\n- In your apps, you can get the user's basic profile information from the\n [`firebase::auth::User`](/docs/reference/cpp/class/firebase/auth/user) object:\n\n ```c++\n firebase::auth::User user = auth-\u003ecurrent_user();\n if (user.is_valid()) {\n std::string name = user.display_name();\n std::string email = user.email();\n std::string photo_url = user.photo_url();\n // The user's ID, unique to the Firebase project.\n // Do NOT use this value to authenticate with your backend server,\n // if you have one. Use firebase::auth::User::Token() instead.\n std::string uid = user.uid();\n }\n ```\n- In your Firebase Realtime Database and Cloud Storage\n [Security Rules](/docs/database/security/user-security), you can\n get the signed-in user's unique user ID from the `auth` variable,\n and use it to control what data a user can access.\n\nYou can allow users to sign in to your app using multiple authentication\nproviders by [linking auth provider credentials to an\nexisting user account.](/docs/auth/cpp/account-linking)\n\nTo sign out a user, call [`SignOut()`](/docs/reference/cpp/class/firebase/auth/auth#signout): \n\n```c++\nauth-\u003eSignOut();\n```"]]
