在 Apple 平台上使用 Facebook 登入進行驗證

您可以讓使用者利用 Facebook 帳戶向 Firebase 進行驗證 將 Facebook Login 或 Facebook Limited Login 整合至您的應用程式中。

事前準備

使用 Swift Package Manager 安裝及管理 Firebase 依附元件。

  1. 在 Xcode 中保持開啟應用程式專案,然後前往「檔案」檔案 >新增套件
  2. 在系統提示時,新增 Firebase Apple 平台 SDK 存放區:
  3.   https://github.com/firebase/firebase-ios-sdk.git
  4. 選擇 Firebase Authentication 程式庫。
  5. 在目標建構設定的「Other Linker Flags」部分中新增 -ObjC 標記。
  6. 完成後,Xcode 會自動開始解析並下載 複製到背景依附元件

接下來,請執行一些設定步驟:

  1. Facebook for Developers 上 網站,請取得應用程式的「應用程式 ID」和「應用程式密鑰」。
  2. 啟用 Facebook 登入:
    1. Firebase 控制台中開啟「Auth」專區。
    2. 在「Sign in method」分頁中,啟用 Facebook 登入功能 方法,並指定您從 Facebook 取得的「應用程式 ID」和「應用程式密鑰」
    3. 接著,請確認您的 OAuth 重新導向 URI (例如 my-app-12345.firebaseapp.com/__/auth/handler) 是您 Facebook 應用程式設定頁面的其中一個 OAuth 重新導向 URIFacebook for Developers 網站 產品設定 >Facebook Login 設定。

實作 Facebook 登入

如何使用「傳統版」,請完成下列步驟。另外 您可以使用 Facebook 有限登入功能,如下一節所示。

  1. 遵循下列步驟,將 Facebook 登入整合至應用程式: 開發人員說明文件當您初始化 FBSDKLoginButton 物件,設定委派代表接收登入,並 登出事件。例如:

    Swift

    let loginButton = FBSDKLoginButton()
    loginButton.delegate = self
    

    Objective-C

    FBSDKLoginButton *loginButton = [[FBSDKLoginButton alloc] init];
    loginButton.delegate = self;
    
    在委派中實作 didCompleteWithResult:error:

    Swift

    func loginButton(_ loginButton: FBSDKLoginButton!, didCompleteWith result: FBSDKLoginManagerLoginResult!, error: Error!) {
      if let error = error {
        print(error.localizedDescription)
        return
      }
      // ...
    }
    

    Objective-C

    - (void)loginButton:(FBSDKLoginButton *)loginButton
        didCompleteWithResult:(FBSDKLoginManagerLoginResult *)result
                        error:(NSError *)error {
      if (error == nil) {
        // ...
      } else {
        NSLog(error.localizedDescription);
      }
    }
    
  2. FirebaseCore 模組匯入至 UIApplicationDelegate和任何其他 應用程式委派所用的 Firebase 模組。 例如,如要使用 Cloud FirestoreAuthentication

    SwiftUI

    import SwiftUI
    import FirebaseCore
    import FirebaseFirestore
    import FirebaseAuth
    // ...
          

    Swift

    import FirebaseCore
    import FirebaseFirestore
    import FirebaseAuth
    // ...
          

    Objective-C

    @import FirebaseCore;
    @import FirebaseFirestore;
    @import FirebaseAuth;
    // ...
          
  3. 設定 FirebaseApp敬上 共用執行個體 application(_:didFinishLaunchingWithOptions:) 方法:

    SwiftUI

    // Use Firebase library to configure APIs
    FirebaseApp.configure()

    Swift

    // Use Firebase library to configure APIs
    FirebaseApp.configure()

    Objective-C

    // Use Firebase library to configure APIs
    [FIRApp configure];
  4. 如果您使用 SwiftUI,則必須建立並附加應用程式委派 透過 UIApplicationDelegateAdaptorApp NSApplicationDelegateAdaptor。您也必須停用應用程式委派功能切換功能。適用對象 詳情請參閱 SwiftUI 操作說明

    SwiftUI

    @main
    struct YourApp: App {
      // register app delegate for Firebase setup
      @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate
    
      var body: some Scene {
        WindowGroup {
          NavigationView {
            ContentView()
          }
        }
      }
    }
          
  5. 使用者成功登入後,您的實作 didCompleteWithResult:error:,取得 並交換 Firebase 憑證:

    Swift

    let credential = FacebookAuthProvider
      .credential(withAccessToken: AccessToken.current!.tokenString)
    

    Objective-C

    FIRAuthCredential *credential = [FIRFacebookAuthProvider
        credentialWithAccessToken:[FBSDKAccessToken currentAccessToken].tokenString];
    

實作 Facebook 有限登入

使用 Facebook 有限登入取代「傳統版」登入 Facebook 登入,完成 步驟如下

  1. 按照下列步驟,將 Facebook 有限登入整合至應用程式: 開發人員說明文件
  2. 針對每個登入要求,產生一個不重複的隨機字串「nonce」, 您將用來確保取得的 ID 權杖是專門在 應用程式驗證要求的回應。這個步驟很重要 以防止重送攻擊 您可以使用下列指令產生經過加密的安全 Nonce SecRandomCopyBytes(_:_:_),如以下範例所示:

    Swift

    private func randomNonceString(length: Int = 32) -> String {
      precondition(length > 0)
      var randomBytes = [UInt8](repeating: 0, count: length)
      let errorCode = SecRandomCopyBytes(kSecRandomDefault, randomBytes.count, &randomBytes)
      if errorCode != errSecSuccess {
        fatalError(
          "Unable to generate nonce. SecRandomCopyBytes failed with OSStatus \(errorCode)"
        )
      }
    
      let charset: [Character] =
        Array("0123456789ABCDEFGHIJKLMNOPQRSTUVXYZabcdefghijklmnopqrstuvwxyz-._")
    
      let nonce = randomBytes.map { byte in
        // Pick a random character from the set, wrapping around if needed.
        charset[Int(byte) % charset.count]
      }
    
      return String(nonce)
    }
    
            

    Objective-C

    // Adapted from https://auth0.com/docs/api-auth/tutorials/nonce#generate-a-cryptographically-random-nonce
    - (NSString *)randomNonce:(NSInteger)length {
      NSAssert(length > 0, @"Expected nonce to have positive length");
      NSString *characterSet = @"0123456789ABCDEFGHIJKLMNOPQRSTUVXYZabcdefghijklmnopqrstuvwxyz-._";
      NSMutableString *result = [NSMutableString string];
      NSInteger remainingLength = length;
    
      while (remainingLength > 0) {
        NSMutableArray *randoms = [NSMutableArray arrayWithCapacity:16];
        for (NSInteger i = 0; i < 16; i++) {
          uint8_t random = 0;
          int errorCode = SecRandomCopyBytes(kSecRandomDefault, 1, &random);
          NSAssert(errorCode == errSecSuccess, @"Unable to generate nonce: OSStatus %i", errorCode);
    
          [randoms addObject:@(random)];
        }
    
        for (NSNumber *random in randoms) {
          if (remainingLength == 0) {
            break;
          }
    
          if (random.unsignedIntValue < characterSet.length) {
            unichar character = [characterSet characterAtIndex:random.unsignedIntValue];
            [result appendFormat:@"%C", character];
            remainingLength--;
          }
        }
      }
    
      return [result copy];
    }
            
    您會在登入要求時傳送 Nonce 的 SHA-256 雜湊, Facebook 會在回應中傳遞任何變更。Firebase 會驗證 雜湊原始 Nonce 並將其與傳送的值進行比較 。

    Swift

    @available(iOS 13, *)
    private func sha256(_ input: String) -> String {
      let inputData = Data(input.utf8)
      let hashedData = SHA256.hash(data: inputData)
      let hashString = hashedData.compactMap {
        String(format: "%02x", $0)
      }.joined()
    
      return hashString
    }
    
            

    Objective-C

    - (NSString *)stringBySha256HashingString:(NSString *)input {
      const char *string = [input UTF8String];
      unsigned char result[CC_SHA256_DIGEST_LENGTH];
      CC_SHA256(string, (CC_LONG)strlen(string), result);
    
      NSMutableString *hashed = [NSMutableString stringWithCapacity:CC_SHA256_DIGEST_LENGTH * 2];
      for (NSInteger i = 0; i < CC_SHA256_DIGEST_LENGTH; i++) {
        [hashed appendFormat:@"%02x", result[i]];
      }
      return hashed;
    }
            
  3. 設定 FBSDKLoginButton 時,請將委派代表設為 接收登入和登出事件,請將追蹤模式設為 FBSDKLoginTrackingLimited,並附加 Nonce。例如:

    Swift

    func setupLoginButton() {
        let nonce = randomNonceString()
        currentNonce = nonce
        loginButton.delegate = self
        loginButton.loginTracking = .limited
        loginButton.nonce = sha256(nonce)
    }
            

    Objective-C

    - (void)setupLoginButton {
      NSString *nonce = [self randomNonce:32];
      self.currentNonce = nonce;
      self.loginButton.delegate = self;
      self.loginButton.loginTracking = FBSDKLoginTrackingLimited
      self.loginButton.nonce = [self stringBySha256HashingString:nonce];
    }
            
    在委派中實作 didCompleteWithResult:error:

    Swift

    func loginButton(_ loginButton: FBSDKLoginButton!, didCompleteWith result: FBSDKLoginManagerLoginResult!, error: Error!) {
      if let error = error {
        print(error.localizedDescription)
        return
      }
      // ...
    }
            

    Objective-C

    - (void)loginButton:(FBSDKLoginButton *)loginButton
        didCompleteWithResult:(FBSDKLoginManagerLoginResult *)result
                        error:(NSError *)error {
      if (error == nil) {
        // ...
      } else {
        NSLog(error.localizedDescription);
      }
    }
            
  4. FirebaseCore 模組匯入至 UIApplicationDelegate和任何其他 應用程式委派所用的 Firebase 模組。 例如,如要使用 Cloud FirestoreAuthentication

    SwiftUI

    import SwiftUI
    import FirebaseCore
    import FirebaseFirestore
    import FirebaseAuth
    // ...
          

    Swift

    import FirebaseCore
    import FirebaseFirestore
    import FirebaseAuth
    // ...
          

    Objective-C

    @import FirebaseCore;
    @import FirebaseFirestore;
    @import FirebaseAuth;
    // ...
          
  5. 設定 FirebaseApp敬上 共用執行個體 application(_:didFinishLaunchingWithOptions:) 方法:

    SwiftUI

    // Use Firebase library to configure APIs
    FirebaseApp.configure()

    Swift

    // Use Firebase library to configure APIs
    FirebaseApp.configure()

    Objective-C

    // Use Firebase library to configure APIs
    [FIRApp configure];
  6. 如果您使用 SwiftUI,則必須建立並附加應用程式委派 透過 UIApplicationDelegateAdaptorApp NSApplicationDelegateAdaptor。您也必須停用應用程式委派功能切換功能。適用對象 詳情請參閱 SwiftUI 操作說明

    SwiftUI

    @main
    struct YourApp: App {
      // register app delegate for Firebase setup
      @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate
    
      var body: some Scene {
        WindowGroup {
          NavigationView {
            ContentView()
          }
        }
      }
    }
          
  7. 使用者成功登入後,您的實作 didCompleteWithResult:error:,請使用 Facebook 的 ID 符記 傳回未經雜湊處理的 Nonce,以取得 Firebase 憑證:

    Swift

    // Initialize a Firebase credential.
    let idTokenString = AuthenticationToken.current?.tokenString
    let nonce = currentNonce
    let credential = OAuthProvider.credential(withProviderID: "facebook.com",
                                              idToken: idTokenString!,
                                              rawNonce: nonce)
            

    Objective-C

    // Initialize a Firebase credential.
    NSString *idTokenString = FBSDKAuthenticationToken.currentAuthenticationToken.tokenString;
    NSString *rawNonce = self.currentNonce;
    FIROAuthCredential *credential = [FIROAuthProvider credentialWithProviderID:@"facebook.com"
                                                                        IDToken:idTokenString
                                                                       rawNonce:rawNonce];
            

透過 Firebase 驗證

最後,使用 Firebase 憑證向 Firebase 進行驗證:

Swift

Auth.auth().signIn(with: credential) { authResult, error in
    if let error = error {
      let authError = error as NSError
      if isMFAEnabled, authError.code == AuthErrorCode.secondFactorRequired.rawValue {
        // The user is a multi-factor user. Second factor challenge is required.
        let resolver = authError
          .userInfo[AuthErrorUserInfoMultiFactorResolverKey] as! MultiFactorResolver
        var displayNameString = ""
        for tmpFactorInfo in resolver.hints {
          displayNameString += tmpFactorInfo.displayName ?? ""
          displayNameString += " "
        }
        self.showTextInputPrompt(
          withMessage: "Select factor to sign in\n\(displayNameString)",
          completionBlock: { userPressedOK, displayName in
            var selectedHint: PhoneMultiFactorInfo?
            for tmpFactorInfo in resolver.hints {
              if displayName == tmpFactorInfo.displayName {
                selectedHint = tmpFactorInfo as? PhoneMultiFactorInfo
              }
            }
            PhoneAuthProvider.provider()
              .verifyPhoneNumber(with: selectedHint!, uiDelegate: nil,
                                 multiFactorSession: resolver
                                   .session) { verificationID, error in
                if error != nil {
                  print(
                    "Multi factor start sign in failed. Error: \(error.debugDescription)"
                  )
                } else {
                  self.showTextInputPrompt(
                    withMessage: "Verification code for \(selectedHint?.displayName ?? "")",
                    completionBlock: { userPressedOK, verificationCode in
                      let credential: PhoneAuthCredential? = PhoneAuthProvider.provider()
                        .credential(withVerificationID: verificationID!,
                                    verificationCode: verificationCode!)
                      let assertion: MultiFactorAssertion? = PhoneMultiFactorGenerator
                        .assertion(with: credential!)
                      resolver.resolveSignIn(with: assertion!) { authResult, error in
                        if error != nil {
                          print(
                            "Multi factor finanlize sign in failed. Error: \(error.debugDescription)"
                          )
                        } else {
                          self.navigationController?.popViewController(animated: true)
                        }
                      }
                    }
                  )
                }
              }
          }
        )
      } else {
        self.showMessagePrompt(error.localizedDescription)
        return
      }
      // ...
      return
    }
    // User is signed in
    // ...
}
    

Objective-C

[[FIRAuth auth] signInWithCredential:credential
                          completion:^(FIRAuthDataResult * _Nullable authResult,
                                       NSError * _Nullable error) {
    if (isMFAEnabled && error && error.code == FIRAuthErrorCodeSecondFactorRequired) {
      FIRMultiFactorResolver *resolver = error.userInfo[FIRAuthErrorUserInfoMultiFactorResolverKey];
      NSMutableString *displayNameString = [NSMutableString string];
      for (FIRMultiFactorInfo *tmpFactorInfo in resolver.hints) {
        [displayNameString appendString:tmpFactorInfo.displayName];
        [displayNameString appendString:@" "];
      }
      [self showTextInputPromptWithMessage:[NSString stringWithFormat:@"Select factor to sign in\n%@", displayNameString]
                           completionBlock:^(BOOL userPressedOK, NSString *_Nullable displayName) {
       FIRPhoneMultiFactorInfo* selectedHint;
       for (FIRMultiFactorInfo *tmpFactorInfo in resolver.hints) {
         if ([displayName isEqualToString:tmpFactorInfo.displayName]) {
           selectedHint = (FIRPhoneMultiFactorInfo *)tmpFactorInfo;
         }
       }
       [FIRPhoneAuthProvider.provider
        verifyPhoneNumberWithMultiFactorInfo:selectedHint
        UIDelegate:nil
        multiFactorSession:resolver.session
        completion:^(NSString * _Nullable verificationID, NSError * _Nullable error) {
          if (error) {
            [self showMessagePrompt:error.localizedDescription];
          } else {
            [self showTextInputPromptWithMessage:[NSString stringWithFormat:@"Verification code for %@", selectedHint.displayName]
                                 completionBlock:^(BOOL userPressedOK, NSString *_Nullable verificationCode) {
             FIRPhoneAuthCredential *credential =
                 [[FIRPhoneAuthProvider provider] credentialWithVerificationID:verificationID
                                                              verificationCode:verificationCode];
             FIRMultiFactorAssertion *assertion = [FIRPhoneMultiFactorGenerator assertionWithCredential:credential];
             [resolver resolveSignInWithAssertion:assertion completion:^(FIRAuthDataResult * _Nullable authResult, NSError * _Nullable error) {
               if (error) {
                 [self showMessagePrompt:error.localizedDescription];
               } else {
                 NSLog(@"Multi factor finanlize sign in succeeded.");
               }
             }];
           }];
          }
        }];
     }];
    }
  else if (error) {
    // ...
    return;
  }
  // User successfully signed in. Get user data from the FIRUser object
  if (authResult == nil) { return; }
  FIRUser *user = authResult.user;
  // ...
}];
    

後續步驟

使用者首次登入後,系統會建立新的使用者帳戶 也就是使用者的名稱和密碼 號碼或驗證提供者資訊,也就是使用者登入時使用的網址。這項新功能 帳戶儲存為 Firebase 專案的一部分,可用來識別 即可限制使用者登入專案中的所有應用程式

  • 在您的應用程式中,您可以透過 User 物件。請參閱管理使用者

  • 在你的Firebase Realtime DatabaseCloud Storage中 查看安全性規則 透過 auth 變數取得已登入使用者的不重複使用者 ID。 控管使用者可以存取的資料

您可以讓使用者透過多重驗證機制登入您的應用程式 將驗證供應商憑證連結至 現有的使用者帳戶

如要登出使用者,請呼叫 signOut:

Swift

let firebaseAuth = Auth.auth()
do {
  try firebaseAuth.signOut()
} catch let signOutError as NSError {
  print("Error signing out: %@", signOutError)
}

Objective-C

NSError *signOutError;
BOOL status = [[FIRAuth auth] signOut:&signOutError];
if (!status) {
  NSLog(@"Error signing out: %@", signOutError);
  return;
}

我們也建議您新增錯誤處理程式碼,適用於完整的驗證範圍 發生錯誤。請參閱處理錯誤