您可以通过将 Facebook 登录或 Facebook 有限登录集成到您的应用中，让您的用户使用他们的 Facebook 帐户通过 Firebase 进行身份验证。
在你开始之前
使用 Swift Package Manager 安装和管理 Firebase 依赖项。
- 在 Xcode 中，打开您的应用程序项目，导航至File > Add Packages 。
- 出现提示时，添加 Firebase Apple 平台 SDK 存储库：
- 选择 Firebase 身份验证库。
- 完成后，Xcode 将自动开始在后台解析和下载您的依赖项。
https://github.com/firebase/firebase-ios-sdk
接下来，执行一些配置步骤：
- 在Facebook for Developers网站上，为您的应用获取App ID和App Secret 。
- 启用 Facebook 登录：
- 在Firebase 控制台中，打开Auth部分。
- 在Sign in method选项卡上，启用Facebook登录方法并指定您从 Facebook 获得的App ID和App Secret 。
- 然后，确保您的OAuth 重定向 URI （例如
my-app-12345.firebaseapp.com/__/auth/handler）在产品的Facebook for Developers站点上的 Facebook 应用程序设置页面中被列为您的OAuth 重定向 URI之一设置 > Facebook 登录配置。
实施 Facebook 登录
要使用“经典”Facebook 登录，请完成以下步骤。或者，您可以使用 Facebook Limited Login，如下一节所示。
- 按照开发人员的文档将 Facebook 登录集成到您的应用程序中。当您初始化
FBSDKLoginButton对象时，设置一个委托来接收登录和注销事件。例如：在您的委托中，实现迅速
let loginButton = FBSDKLoginButton() loginButton.delegate = self
目标-C
FBSDKLoginButton *loginButton = [[FBSDKLoginButton alloc] init]; loginButton.delegate = self;
didCompleteWithResult:error:。迅速
func loginButton(_ loginButton: FBSDKLoginButton!, didCompleteWith result: FBSDKLoginManagerLoginResult!, error: Error!) { if let error = error { print(error.localizedDescription) return } // ... }目标-C
- (void)loginButton:(FBSDKLoginButton *)loginButton didCompleteWithResult:(FBSDKLoginManagerLoginResult *)result error:(NSError *)error { if (error == nil) { // ... } else { NSLog(error.localizedDescription); } } - 在您的
UIApplicationDelegate中导入FirebaseCore模块，以及您的应用委托使用的任何其他Firebase 模块。例如，要使用 Cloud Firestore 和身份验证：斯威夫特用户界面
import SwiftUI import FirebaseCore import FirebaseFirestore import FirebaseAuth // ...迅速
import FirebaseCore import FirebaseFirestore import FirebaseAuth // ...目标-C
@import FirebaseCore; @import FirebaseFirestore; @import FirebaseAuth; // ... - 在您的应用委托的
application(_:didFinishLaunchingWithOptions:)方法中配置一个FirebaseApp共享实例：斯威夫特用户界面
// Use Firebase library to configure APIs FirebaseApp.configure()
迅速
// Use Firebase library to configure APIs FirebaseApp.configure()
目标-C
// Use Firebase library to configure APIs [FIRApp configure];
- 如果您使用的是 SwiftUI，则必须创建一个应用程序委托并通过
UIApplicationDelegateAdaptor或NSApplicationDelegateAdaptor将其附加到您的App结构。您还必须禁用应用委托调配。有关详细信息，请参阅SwiftUI 说明。斯威夫特用户界面
@main struct YourApp: App { // register app delegate for Firebase setup @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate var body: some Scene { WindowGroup { NavigationView { ContentView() } } } } - 用户成功登录后，在
didCompleteWithResult:error:的实现中，获取登录用户的访问令牌并将其交换为 Firebase 凭证：迅速
let credential = FacebookAuthProvider .credential(withAccessToken: AccessToken.current!.tokenString)
目标-C
FIRAuthCredential *credential = [FIRFacebookAuthProvider credentialWithAccessToken:[FBSDKAccessToken currentAccessToken].tokenString];
实施 Facebook 有限登录
要使用 Facebook 有限登录而不是“经典”Facebook 登录，请完成以下步骤。
- 按照开发人员的文档将 Facebook Limited Login 集成到您的应用程序中。
- 对于每个登录请求，生成一个唯一的随机字符串——一个“nonce”——你将使用它来确保你获得的 ID 令牌是专门为响应你的应用程序的身份验证请求而授予的。此步骤对于防止重放攻击很重要。您可以使用
SecRandomCopyBytes(_:_:_)生成加密安全随机数，如以下示例所示：您将随登录请求一起发送随机数的 SHA-256 哈希值，Facebook 将在响应中原封不动地传递该哈希值。 Firebase 通过散列原始随机数并将其与 Facebook 传递的值进行比较来验证响应。迅速
// Adapted from https://auth0.com/docs/api-auth/tutorials/nonce#generate-a-cryptographically-random-nonce private func randomNonceString(length: Int = 32) -> String { precondition(length > 0) let charset: [Character] = Array("0123456789ABCDEFGHIJKLMNOPQRSTUVXYZabcdefghijklmnopqrstuvwxyz-._") var result = "" var remainingLength = length while remainingLength > 0 { let randoms: [UInt8] = (0 ..< 16).map { _ in var random: UInt8 = 0 let errorCode = SecRandomCopyBytes(kSecRandomDefault, 1, &random) if errorCode != errSecSuccess { fatalError( "Unable to generate nonce. SecRandomCopyBytes failed with OSStatus \(errorCode)" ) } return random } randoms.forEach { random in if remainingLength == 0 { return } if random < charset.count { result.append(charset[Int(random)]) remainingLength -= 1 } } } return result }目标-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]; }迅速
@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 }目标-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; } - 当您设置
FBSDKLoginButton时，设置一个委托来接收登录和注销事件，将跟踪模式设置为FBSDKLoginTrackingLimited，并附加一个随机数。例如：在您的委托中，实现迅速
func setupLoginButton() { let nonce = randomNonceString() currentNonce = nonce loginButton.delegate = self loginButton.loginTracking = .limited loginButton.nonce = sha256(nonce) }目标-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]; }didCompleteWithResult:error:。迅速
func loginButton(_ loginButton: FBSDKLoginButton!, didCompleteWith result: FBSDKLoginManagerLoginResult!, error: Error!) { if let error = error { print(error.localizedDescription) return } // ... }目标-C
- (void)loginButton:(FBSDKLoginButton *)loginButton didCompleteWithResult:(FBSDKLoginManagerLoginResult *)result error:(NSError *)error { if (error == nil) { // ... } else { NSLog(error.localizedDescription); } } - 在您的
UIApplicationDelegate中导入FirebaseCore模块，以及您的应用委托使用的任何其他Firebase 模块。例如，要使用 Cloud Firestore 和身份验证：斯威夫特用户界面
import SwiftUI import FirebaseCore import FirebaseFirestore import FirebaseAuth // ...迅速
import FirebaseCore import FirebaseFirestore import FirebaseAuth // ...目标-C
@import FirebaseCore; @import FirebaseFirestore; @import FirebaseAuth; // ... - 在您的应用委托的
application(_:didFinishLaunchingWithOptions:)方法中配置一个FirebaseApp共享实例：斯威夫特用户界面
// Use Firebase library to configure APIs FirebaseApp.configure()
迅速
// Use Firebase library to configure APIs FirebaseApp.configure()
目标-C
// Use Firebase library to configure APIs [FIRApp configure];
- 如果您使用的是 SwiftUI，则必须创建一个应用程序委托并通过
UIApplicationDelegateAdaptor或NSApplicationDelegateAdaptor将其附加到您的App结构。您还必须禁用应用委托调配。有关详细信息，请参阅SwiftUI 说明。斯威夫特用户界面
@main struct YourApp: App { // register app delegate for Firebase setup @UIApplicationDelegateAdaptor(AppDelegate.self) var delegate var body: some Scene { WindowGroup { NavigationView { ContentView() } } } } - 用户成功登录后，在
didCompleteWithResult:error:的实现中，使用来自 Facebook 响应的 ID 令牌和未散列的随机数来获取 Firebase 凭证：迅速
// Initialize a Firebase credential. let idTokenString = AuthenticationToken.current?.tokenString let nonce = currentNonce let credential = OAuthProvider.credential(withProviderID: "facebook.com", idToken: idTokenString!, rawNonce: nonce)目标-C
// Initialize a Firebase credential. NSString *idTokenString = FBSDKAuthenticationToken.currentAuthenticationToken.tokenString; NSString *rawNonce = self.currentNonce; FIROAuthCredential *credential = [FIROAuthProvider credentialWithProviderID:@"facebook.com" IDToken:idTokenString rawNonce:rawNonce];
使用 Firebase 进行身份验证
最后，使用 Firebase 凭据通过 Firebase 进行身份验证：
迅速
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
// ...
}
目标-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;
// ...
}];
下一步
用户首次登录后，将创建一个新的用户帐户并将其链接到用户登录所用的凭据，即用户名和密码、电话号码或身份验证提供商信息。这个新帐户存储为您的 Firebase 项目的一部分，可用于在项目中的每个应用程序中识别用户，无论用户如何登录。
在您的 Firebase Realtime Database 和 Cloud Storage Security Rules中，您可以从
auth变量中获取登录用户的唯一用户 ID，并使用它来控制用户可以访问的数据。
您可以允许用户使用多个身份验证提供程序登录您的应用程序，方法是将身份验证提供程序凭据链接到现有用户帐户。
要注销用户，请调用signOut: 。
迅速
let firebaseAuth = Auth.auth()
do {
try firebaseAuth.signOut()
} catch let signOutError as NSError {
print("Error signing out: %@", signOutError)
}
目标-C
NSError *signOutError;
BOOL status = [[FIRAuth auth] signOut:&signOutError];
if (!status) {
NSLog(@"Error signing out: %@", signOutError);
return;
}
您可能还想为所有身份验证错误添加错误处理代码。请参阅处理错误。