【环境】Xcode 12.0.1，macOS 10.15.7

一、ViewController 代码

1、创建一个新工程，取名为 SignInWithApple，设置为自动签名
2、为其添加 Sign in with Apple Capability
3、打开 ViewController.h，导入

#import <AuthenticationServices/AuthenticationServices.h>

4、先创建一个 UIButton，或者使用 AuthenticationService 里自带的 ASAuthorizationAppleIDButton，注意，这个 button 仅仅包含UI，点击事件逻辑还是得自己添加。

    UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];
    [button setBackgroundColor:[UIColor blueColor]];
    [button setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [button setTitle:@"Login" forState:UIControlStateNormal];
    button.frame = CGRectMake(0, 0, 40 * 1.73, 40);
    button.center = self.view.center;
    [button addTarget:self action:@selector(onLoginClick) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];

或者

    ASAuthorizationAppleIDButton *button = [ASAuthorizationAppleIDButton
                                            buttonWithType:ASAuthorizationAppleIDButtonTypeSignUp
                                            style:ASAuthorizationAppleIDButtonStyleBlack];
    button.center = self.view.center;
    [button addTarget:self action:@selector(onLoginClick) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:button];

5、创建对应的点击方法

- (void)onLoginClick {
    ASAuthorizationAppleIDProvider *provider = [[ASAuthorizationAppleIDProvider alloc] init];
    ASAuthorizationAppleIDRequest *request = [provider createRequest];
    
    // 获取 用户名 和 Email（同一 BundleId 首次使用 Sign in with Apple 才有对应的值返回）
    request.requestedScopes = @[
        ASAuthorizationScopeFullName,
        ASAuthorizationScopeEmail,
    ];
    
    ASAuthorizationController *controller = [[ASAuthorizationController alloc] initWithAuthorizationRequests:@[request]];
    controller.delegate = self;
    controller.presentationContextProvider = self;
    [controller performRequests];
}

6、实现代理 ASAuthorizationControllerDelegate

- (void)authorizationController:(ASAuthorizationController *)controller didCompleteWithAuthorization:(ASAuthorization *)authorization {
    // 鉴权成功
    // 将登录凭证保存到钥匙串中
    if ([authorization.credential isKindOfClass:[ASAuthorizationAppleIDCredential class]]) {
        // 如果是 AppleID 凭证，保存
        ASAuthorizationAppleIDCredential *credential = (ASAuthorizationAppleIDCredential *)authorization.credential;
        
        // email 和 fullName，仅在同一 BundleId 第一次使用 Sign in with Apple 时才有值
        NSLog(@"user = %@", credential.user);
        NSLog(@"state = %@", credential.state);
        NSLog(@"authorizedScopes = %@", credential.authorizedScopes);
        NSLog(@"authorizationCode = %@", credential.authorizationCode);
        NSLog(@"identityToken = %@", credential.identityToken);
        NSLog(@"email = %@", credential.email);
        NSLog(@"namePrefix = %@", credential.fullName.namePrefix);
        NSLog(@"givenName = %@", credential.fullName.givenName);
        NSLog(@"middleName = %@", credential.fullName.middleName);
        NSLog(@"familyName = %@", credential.fullName.familyName);
        NSLog(@"nameSuffix = %@", credential.fullName.nameSuffix);
        NSLog(@"nickname = %@", credential.fullName.nickname);
        NSLog(@"%ld", (long)credential.realUserStatus);

        NSData *userData = [credential.user dataUsingEncoding:NSUTF8StringEncoding];
        NSDictionary *attributes = @{
            (NSString *)kSecClass: (NSString *)kSecClassGenericPassword,
            // 单用户登录，账号可以写死
            (NSString *)kSecAttrAccount: @"appAccount",
            // 当 kSecClass = kSecClassGenericPassword 时，kSecValueData 里的内容会加密，更安全
            (NSString *)kSecValueData: userData,
        };
        CFTypeRef result;
        OSStatus res = SecItemAdd((__bridge CFDictionaryRef)attributes, (CFTypeRef *)&result);
        if (res == errSecSuccess) {
            NSLog(@"success");
        }
    }
}

- (void)authorizationController:(ASAuthorizationController *)controller didCompleteWithError:(NSError *)error {
    // 鉴权失败
    NSLog(@"err: %@", error);
}

7、实现代理 ASAuthorizationControllerPresentationContextProviding

- (ASPresentationAnchor)presentationAnchorForAuthorizationController:(ASAuthorizationController *)controller {
    // 在哪个 Window 展示登录框
    return UIApplication.sharedApplication.windows.firstObject;
}

二、AppDelegate 代码

1、在 AppDelegate.h 中添加

#import <AuthenticationServices/AuthenticationServices.h>

2、在 AppDelegate.m 中 didFinishLaunchingWithOptions 中添加

    [[[ASAuthorizationAppleIDProvider alloc] init] getCredentialStateForUserID:[self getUserId] completion:^(ASAuthorizationAppleIDProviderCredentialState credentialState, NSError * _Nullable error) {
        // 查询当前账号是否在钥匙串中有记录了，不需要用户重复登录
        switch (credentialState) {
            case ASAuthorizationAppleIDProviderCredentialRevoked:
                NSLog(@"ASAuthorizationAppleIDProviderCredentialRevoked");
                break;
            case ASAuthorizationAppleIDProviderCredentialAuthorized:
                NSLog(@"ASAuthorizationAppleIDProviderCredentialAuthorized");
                break;
            case ASAuthorizationAppleIDProviderCredentialNotFound:
                NSLog(@"ASAuthorizationAppleIDProviderCredentialNotFound");
                break;
            case ASAuthorizationAppleIDProviderCredentialTransferred:
                NSLog(@"ASAuthorizationAppleIDProviderCredentialTransferred");
                break;
            default:
                break;
        }
    }];

其中 getUserId 是获取保存在钥匙串中的 userId

- (NSString *)getUserId {
    // 单用户登录，直接写死账号，只需要查到 userId 即可
    NSDictionary *query = @{
        (NSString *)kSecClass: (NSString *)kSecClassGenericPassword,
        (NSString *)kSecMatchLimit: (NSString *)kSecMatchLimitOne, // 只返回一个记录
        (NSString *)kSecAttrAccount: @"appAccount", // 账号写死
        (NSString *)kSecReturnData: @(YES), // 需要返回 Item 的 Data，数据保存在这里
        // 返回对象的类型不同
        // 值为 YES 时，attributes 和 data 放在同一个 CFDictionaryRef 中返回
        // 值为 NO 时，单独返回 data，放在 CFDataRef 中返回
        (NSString *)kSecReturnAttributes: @(YES),
    };
    CFTypeRef result;
    OSStatus res = SecItemCopyMatching((__bridge CFDictionaryRef)query, (CFTypeRef *)&result);
    if (res == errSecSuccess) {
        NSDictionary *resDic = (__bridge_transfer NSDictionary *)result;
        NSData * data = resDic[(NSString *)kSecValueData];
        NSString *user = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
        return user;
    } else {
        return nil;
    }
}

苹果登录集成结束

参考文档
https://developer.apple.com/documentation/authenticationservices
Demo 地址
https://github.com/huangrrui/Sign-in-with-Apple