Demo of using Apple Sign in with Supabase and Unity

AppleSignIn.cs

using System;
using System.Text;
using AppleAuth;
using AppleAuth.Enums;
using AppleAuth.Extensions;
using AppleAuth.Interfaces;
using AppleAuth.Native;
using TMPro;
using UnityEngine;

namespace App {
    public class AppleSignIn : MonoBehaviour {
        private AppleAuthManager _appleAuthManager;

        private SupabaseStuff _supabaseStuff;

        public TMP_InputField errorLog;

        private string _nonce;
        private string _nonceVerify;

        private void Start() {
            // If the current platform is supported
            if (AppleAuthManager.IsCurrentPlatformSupported) {
                // Creates a default JSON deserializer, to transform JSON Native responses to C# instances
                PayloadDeserializer deserializer = new PayloadDeserializer();
                // Creates an Apple Authentication manager with the deserializer
                _appleAuthManager = new AppleAuthManager(deserializer);
                errorLog.text += "Apple auth started";
            } else {
                errorLog.text += "Apple auth not supported";
            }


            if (TryGetComponent(out SupabaseStuff o))
                _supabaseStuff = o;
            else {
                errorLog.text += "Can't find Supabase Stuff";
            }
        }

        private void Update() {
            _appleAuthManager?.Update();
        }

        private const string APPLE_USER_ID_KEY = "appleUserKey";

        public void PerformSignIn() {
            _nonce = null;
            _nonceVerify = null;

            if (_appleAuthManager == null) {
                errorLog.text = "Apple Sign In Not Available";
                return;
            }

            AppleAuthLoginArgs loginArgs =
                new AppleAuthLoginArgs(LoginOptions.IncludeEmail | LoginOptions.IncludeFullName);

            try {
                errorLog.text += "Apple login start (no nonce)";
                _appleAuthManager.LoginWithAppleId(loginArgs, SuccessCallback, ErrorCallback);
                errorLog.text += "Apple login done (no nonce)";
            } catch (Exception e) {
                errorLog.text += e.Message;
                Debug.LogException(e);
            }
        }

        public void PerformSignInWithNonce() {
            if (_appleAuthManager == null) {
                errorLog.text = "Apple Sign In Not Available";
                return;
            }

            _nonce = Supabase.Gotrue.Helpers.GenerateNonce();
            _nonceVerify = Supabase.Gotrue.Helpers.GenerateSHA256NonceFromRawNonce(_nonce);

            errorLog.text += $"\nNonce sent to Apple:\n {_nonce}";
            errorLog.text += $"\nNonce Hash: {_nonceVerify}\n";

            AppleAuthLoginArgs loginArgs =
                new AppleAuthLoginArgs(LoginOptions.IncludeEmail | LoginOptions.IncludeFullName, _nonceVerify);

            try {
                errorLog.text += "Apple login start (nonce)";
                _appleAuthManager.LoginWithAppleId(loginArgs, SuccessCallback, ErrorCallback);
                errorLog.text += "Apple login done (nonce)";
            } catch (Exception e) {
                errorLog.text += e.Message;
                Debug.LogException(e);
            }
        }

        private void ErrorCallback(IAppleError error) {
            errorLog.text += $"{error.GetAuthorizationErrorCode()} {error.LocalizedFailureReason}";
        }

        private void SuccessCallback(ICredential credential) {
            if (credential == null) errorLog.text += " null credential?";

            errorLog.text += "success!";

            // Obtained credential, cast it to IAppleIDCredential
            if (credential is IAppleIDCredential appleIdCredential) {
                // Apple User ID
                // You should save the user ID somewhere in the device
                string userId = appleIdCredential.User;
                PlayerPrefs.SetString(APPLE_USER_ID_KEY, userId);

                // Email (Received ONLY in the first login)
                string email = appleIdCredential.Email;
                if (email != null) PlayerPrefs.SetString("email", email);

                // Full name (Received ONLY in the first login)
                // IPersonName fullName = appleIdCredential.FullName;
                // PlayerPrefs.SetString("familyName", appleIdCredential.FullName.FamilyName);
                // PlayerPrefs.SetString("givenName", appleIdCredential.FullName.GivenName);

                // Identity token
                string identityToken = Encoding.UTF8.GetString(appleIdCredential.IdentityToken,
                    0,
                    appleIdCredential.IdentityToken.Length);
                PlayerPrefs.SetString("identityToken", identityToken);

                // Authorization code
                string authorizationCode = Encoding.UTF8.GetString(appleIdCredential.AuthorizationCode,
                    0,
                    appleIdCredential.AuthorizationCode.Length);
                PlayerPrefs.SetString("authCode", authorizationCode);

                errorLog.text += "Apple sign in worked!\n";

                // And now you have all the information to create/login a user in your system

                errorLog.text += $"Identity token from Apple: \n{identityToken}";

                _supabaseStuff.AssignId(identityToken, _nonce, _nonceVerify);
            } else {
                errorLog.text += "credential is not a IAppleIDCredential";
            }
        }
    }
}