[Sign in with Apple Unity official example] Showcase how to sign in with Apple account in unity

Example.cs

public SignInWithApple signInWithApple;

signInWithApple.Login((args) =>
{
    if(!string.IsNullOrEmpty(args.error))
    {
        LogMessage("Apple -> sign in error:" + args.error);
        return;
    }
    string idToken = args.userInfo.idToken;
    LogMessage("Apple --> Identity Token:\n"+idToken);

    // use idToken to login to PlayFab or any other web services
});

SignInWithApple.cs

using System;
using System.Collections.Concurrent;
using System.Runtime.InteropServices;
using AOT;
using UnityEngine.Events;

namespace UnityEngine.SignInWithApple
{
    public enum UserDetectionStatus
    {
        LikelyReal,
        Unknown,
        Unsupported
    }

    public enum UserCredentialState
    {
        Revoked,
        Authorized,
        NotFound
    }

    public struct UserInfo
    {
        public string userId;
        public string email;
        public string displayName;

        public string idToken;
        public string error;

        public UserDetectionStatus userDetectionStatus;
    }

    [System.Serializable]
    public class SignInWithAppleEvent : UnityEvent<SignInWithApple.CallbackArgs>
    {
    }

    public class SignInWithApple : MonoBehaviour
    {
        private static Callback s_LoginCompletedCallback;
        private static Callback s_CredentialStateCallback;

        private static readonly ConcurrentQueue<Action> s_EventQueue = new ConcurrentQueue<Action>();

        public struct CallbackArgs
        {
            /// <summary>
            /// The state of the user's authorization.
            /// </summary>
            public UserCredentialState credentialState;

            /// <summary>
            /// The logged in user info after the call is done.
            /// </summary>
            public UserInfo userInfo;

            /// <summary>
            /// Whether the call ends up with an error.
            /// </summary>
            public string error;
        }

        public delegate void Callback(CallbackArgs args);

        private delegate void LoginCompleted(int result, UserInfo info);

        [MonoPInvokeCallback(typeof(LoginCompleted))]
        private static void LoginCompletedCallback(int result, [MarshalAs(UnmanagedType.Struct)]UserInfo info)
        {
            var args = new CallbackArgs();
            if (result != 0)
            {
                args.userInfo = new UserInfo
                {
                    idToken = info.idToken,
                    displayName = info.displayName,
                    email = info.email,
                    userId = info.userId,
                    userDetectionStatus = info.userDetectionStatus
                };
            }
            else
            {
                args.error = info.error;
            }

            s_LoginCompletedCallback(args);
            s_LoginCompletedCallback = null;
        }

        private delegate void GetCredentialStateCompleted(UserCredentialState state);

        [MonoPInvokeCallback(typeof(GetCredentialStateCompleted))]
        private static void GetCredentialStateCallback([MarshalAs(UnmanagedType.SysInt)]UserCredentialState state)
        {
            
            var args = new CallbackArgs
            {
                credentialState = state
            };

            s_CredentialStateCallback(args);
            s_CredentialStateCallback = null;
        }

        #region events

        [Header("Event fired when login is complete.")]
        public SignInWithAppleEvent onLogin;

        [Header("Event fired when the users credential state has been retrieved.")]
        public SignInWithAppleEvent onCredentialState;

        [Header("Event fired when there is an error.")]
        public SignInWithAppleEvent onError;

        #endregion

        /// <summary>
        /// Get credential state and trigger onCredentialState or onError event when action is completed.
        /// </summary>
        /// <param name="userID">The user id to query the credential state on.</param>
        public void GetCredentialState(string userID)
        {
            GetCredentialState(userID, TriggerCredentialStateEvent);
        }

        /// <summary>
        /// Invoke login and provide a custom callback when action is completed.
        /// When a custom trigger is used, the onCredentialState or onError unity event won't trigger.
        /// </summary>
        /// <param name="userID">The user id to query the credential state on.</param>
        /// <param name="callback">The custom callback to trigger when action is completed.</param>
        public void GetCredentialState(string userID, Callback callback)
        {
            if (s_CredentialStateCallback != null)
                throw new InvalidOperationException("Credential state fetch called while another request is in progress");
            s_CredentialStateCallback = callback;

            GetCredentialStateInternal(userID);
   
        }

        private void GetCredentialStateInternal(string userID)
        {
#if (UNITY_IOS || UNITY_TVOS) && !UNITY_EDITOR
            IntPtr cback = IntPtr.Zero;
            GetCredentialStateCompleted d = GetCredentialStateCallback;
            cback = Marshal.GetFunctionPointerForDelegate(d);

            UnitySignInWithApple_GetCredentialState(userID, cback);
            
#endif
        }

        /// <summary>
        /// Invoke login and trigger onLogin or onError event when login is completed.
        /// </summary>
        public void Login()
        {
            Login(TriggerOnLoginEvent);
        }

        /// <summary>
        /// Invoke login and provide a custom callback when login is completed.
        /// When a custom trigger is used, the onLogin or onError unity event won't trigger.
        /// </summary>
        /// <param name="callback">The custom callback to trigger when login is completed.</param>
        public void Login(Callback callback)
        {
            Debug.Log("siwa Login");
            if (s_LoginCompletedCallback != null)
                throw new InvalidOperationException("Login called while another login is in progress");
            s_LoginCompletedCallback = callback;

            LoginInternal();
        }

        private void LoginInternal()
        {
            Debug.Log("siwa LoginInternal");
#if (UNITY_IOS || UNITY_TVOS) && !UNITY_EDITOR
            IntPtr cback = IntPtr.Zero;
            LoginCompleted d = LoginCompletedCallback;
            cback = Marshal.GetFunctionPointerForDelegate(d);

            UnitySignInWithApple_Login(cback);
#endif
        }

        private void TriggerOnLoginEvent(CallbackArgs args)
        {
            if (args.error != null)
            {
                TriggerOnErrorEvent(args);
                return;
            }

            s_EventQueue.Enqueue(delegate ()
            {
                if (onLogin != null)
                {
                    onLogin.Invoke(args);
                }
            });
        }

        private void TriggerCredentialStateEvent(CallbackArgs args)
        {
            if (args.error != null)
            {
                TriggerOnErrorEvent(args);
                return;
            }

            s_EventQueue.Enqueue(delegate ()
            {
                if (onCredentialState != null)
                {
                    onCredentialState.Invoke(args);
                }
            });
        }

        private void TriggerOnErrorEvent(CallbackArgs args)
        {
            s_EventQueue.Enqueue(delegate ()
            {
                if (onError != null)
                {
                    onError.Invoke(args);
                }
            });
        }

        public void Update()
        {
            Action action;
            while (s_EventQueue.TryDequeue(out action))
            {
                action.Invoke();
            }
        }

        #region native hooks
#if (UNITY_IOS || UNITY_TVOS) && !UNITY_EDITOR
        [DllImport("__Internal")]
        private static extern void UnitySignInWithApple_Login(IntPtr callback);

        [DllImport("__Internal")]
        private static extern void UnitySignInWithApple_GetCredentialState(string userID, IntPtr callback);
#endif
        #endregion
    }
}

UnitySignInWithApple.m

#import <Foundation/Foundation.h>
#import <AuthenticationServices/AuthenticationServices.h>
#import "UnityAppController.h"

struct UserInfo
{
    const char * userId;
    const char * email;
    const char * displayName;

    const char * idToken;
    const char * error;

    ASUserDetectionStatus userDetectionStatus;
};

typedef void (*SignInWithAppleCallback)(int result, struct UserInfo s1);
API_AVAILABLE(ios(13.0), tvos(13.0))
typedef void (*CredentialStateCallback)(ASAuthorizationAppleIDProviderCredentialState state);

API_AVAILABLE(ios(13.0), tvos(13.0))
@interface UnitySignInWithApple : NSObject<ASAuthorizationControllerDelegate, ASAuthorizationControllerPresentationContextProviding>

@property (nonatomic) SignInWithAppleCallback loginCallback;
@property (nonatomic) CredentialStateCallback credentialStateCallback;

@end

API_AVAILABLE(ios(13.0), tvos(13.0))
static UnitySignInWithApple* _unitySignInWithAppleInstance;

@implementation UnitySignInWithApple
{
    ASAuthorizationAppleIDRequest* request;
}

+(UnitySignInWithApple*)instance
{
    if (_unitySignInWithAppleInstance == nil)
        _unitySignInWithAppleInstance = [[UnitySignInWithApple alloc] init];
    return _unitySignInWithAppleInstance;
}

-(void)startRequest
{
    if (@available(iOS 13.0, tvOS 13.0, *)) {
        ASAuthorizationAppleIDProvider* provider = [[ASAuthorizationAppleIDProvider alloc] init];
        request = [provider createRequest];
        [request setRequestedScopes: @[ASAuthorizationScopeEmail, ASAuthorizationScopeFullName]];

        ASAuthorizationController* controller = [[ASAuthorizationController alloc] initWithAuthorizationRequests:@[request]];
        controller.delegate = self;
        controller.presentationContextProvider = self;
        [controller performRequests];
    } else {
        // Fallback on earlier versions
    }
}

- (void)getCredentialState:(NSString *)userID
{
    ASAuthorizationAppleIDProvider* provider = [[ASAuthorizationAppleIDProvider alloc] init];
    [provider getCredentialStateForUserID:userID
                               completion:^(ASAuthorizationAppleIDProviderCredentialState credentialState, NSError * _Nullable error) {
        self.credentialStateCallback(credentialState);
    }];
}

-(ASPresentationAnchor)presentationAnchorForAuthorizationController:(ASAuthorizationController *)controller
{
    return _UnityAppController.window;
}

-(void)authorizationController:(ASAuthorizationController *)controller didCompleteWithAuthorization:(ASAuthorization *)authorization
{
    if (self.loginCallback)
    {
        struct UserInfo data;

        if (@available(iOS 13.0, tvOS 13.0, *)) {
            ASAuthorizationAppleIDCredential* credential = (ASAuthorizationAppleIDCredential*)authorization.credential;
            NSString* idToken = [[NSString alloc] initWithData:credential.identityToken encoding:NSUTF8StringEncoding];
            NSPersonNameComponents* name = credential.fullName;

            data.idToken = [idToken UTF8String];

            data.displayName = [[NSPersonNameComponentsFormatter localizedStringFromPersonNameComponents:name
                                                                                                   style:NSPersonNameComponentsFormatterStyleDefault
                                                                                                 options:0] UTF8String];
            data.email = [credential.email UTF8String];
            data.userId = [credential.user UTF8String];
            data.userDetectionStatus = credential.realUserStatus;
            data.error = "";
            self.loginCallback(1, data);
        } else {
            // Fallback on earlier versions
        }
    }
}

-(void)authorizationController:(ASAuthorizationController *)controller didCompleteWithError:(NSError *)error
{
    if (self.loginCallback)
    {
        // All members need to be set to a non-null value.
        struct UserInfo data;
        data.idToken = "";
        data.displayName = "";
        data.email = "";
        data.userId = "";
        data.userDetectionStatus = 1;
        data.error = [error.localizedDescription UTF8String];
        self.loginCallback(0, data);
    }
}

@end

void UnitySignInWithApple_Login(SignInWithAppleCallback callback)
{
    if (@available(iOS 13.0, tvOS 13.0, *)) {
        UnitySignInWithApple* login = [UnitySignInWithApple instance];
        login.loginCallback = callback;
        [login startRequest];
    } else {
        // Fallback on earlier versions
    }
}

API_AVAILABLE(ios(13.0), tvos(13.0))
void UnitySignInWithApple_GetCredentialState(const char *userID, CredentialStateCallback callback)
{
    if (@available(iOS 13.0, tvOS 13.0, *)) {
        UnitySignInWithApple* login = [UnitySignInWithApple instance];
        login.credentialStateCallback = callback;
        [login getCredentialState: [NSString stringWithUTF8String: userID]];
    } else {
        // Fallback on earlier versions
    }
}