QuickLogin: AuthorizationCode is null

As a follow-up to https://github.com/lupidan/apple-signin-unity/issues/132, which could be resolved by using version 1.4.2, I am still facing a problem with the QuickLogin under iOS 15.1:

My code now throws an NRE because appleIdCredential.AuthorizationCode is null (previously, it was always set). Note that IdentityToken is available (not null). Just the AuthorizationCode is null.

I also noticed that - if that happens - AuthorizationCode is still null when I then try to login with the regular login, i.e. without using QuickLogin. Only if I restart the app completely, skip the QuickLogin and then use the regular Apple login, the AuthorizationCode returns a value again.

So it seems as if QuickLogin won’t deliver an authorization code anymore, which basically breaks the functionality, as I need both tokens to login to my app. 😕

[bhupiister]

I came around same issue. Authorization code was null when using QuickLogin after using LoginWithAppleId. I am using it to authenticate firebase and luckily firebase is ok with AuthorizationCode being null. Firebase.Auth.Credential credential = Firebase.Auth.OAuthProvider.GetCredential("apple.com", appleIdToken, rawNonce, null); Firebase GetCredential Documentation AuthorizationCode will only be passed once, as @lupidan said. @lupidan I would suggest you to modify your firebase example with unity and make 4th parameter of GetCredential as null.

I’ll leave a code for anyone wanting help on linking firebase with Apple ID

Spoiler: I am making a guest account first and then linking it with the Apple ID(Firebase) because of my game logic. You can use SignInWithCredentialAsync instead of LinkAndRetrieveDataWithCredentialAsync

public void SignInWithAppleID()//Sing in with apple Button command here
{
    SignInWithAppleID(userReceived =>
    {
        if (userReceived != null)
        {
            user = userReceived;//If everything is successful, this will be current logged in firebase user.
            Debug.Log(user.UserId);//This will give firebase userid
        }
        else
        {
            //Failed to receive firebase user
        }
    });
}
public void SignInWithAppleID(Action<FirebaseUser> firebaseAuthCallback)
{

    string rawNonce = GenerateRandomString(32);//See lupidan example for this function
    string nonce = GenerateSHA256NonceFromRawNonce(rawNonce);//See lupidan example for this function
    AppleAuthQuickLoginArgs quickLoginArgs = new AppleAuthQuickLoginArgs(nonce);

    // Quick login should succeed if the credential was authorized before and not revoked
    appleAuthManager.QuickLogin(quickLoginArgs, credential =>
    {
        var appleIdCredential = credential as IAppleIDCredential;
        if (appleIdCredential != null)
        {
            // If it's an Apple credential, save the user ID, for later logins
            PlayerPrefs.SetString(AppleUserIdKey, credential.User);            
            PerformFirebaseAuthentication(appleIdCredential, rawNonce, firebaseAuthCallback);
        }
    },
    error =>
    {
        // If Quick Login fails, we should show the normal sign in with apple menu, to allow for a normal Sign In with apple
        var authorizationErrorCode = error.GetAuthorizationErrorCode();
        Debug.LogWarning("Quick Login Failed " + authorizationErrorCode.ToString() + " " + error.ToString());
        SignInWithApple(userReceived =>
        {
            user = userReceived;
            if (user != null)
            {
                firebaseAuthCallback(user);
            }
            else
            {
                //Firebase auth was cancelled or failed
                firebaseAuthCallback(null);
            }
        });
    });
}

private void SignInWithApple(Action<FirebaseUser> firebaseAuthCallback)
{
    string rawNonce = GenerateRandomString(32);
    string nonce = GenerateSHA256NonceFromRawNonce(rawNonce);
    AppleAuthLoginArgs loginArgs = new AppleAuthLoginArgs(LoginOptions.IncludeEmail | LoginOptions.IncludeFullName, nonce);

    this.appleAuthManager.LoginWithAppleId(loginArgs, credential =>
    {
        // If a sign in with apple succeeds, we should have obtained the credential with the user id, name, and email, save it
        var appleIdCredential = credential as IAppleIDCredential;
        if (appleIdCredential != null)
        {
            PlayerPrefs.SetString(AppleUserIdKey, credential.User);
            PerformFirebaseAuthentication(appleIdCredential, rawNonce, firebaseAuthCallback);
        }
    },
    error =>
    {
        var authorizationErrorCode = error.GetAuthorizationErrorCode();
        Debug.LogWarning("Sign in with Apple failed " + authorizationErrorCode.ToString() + " " + error.ToString());
        firebaseAuthCallback(null);
    });
}

private void PerformFirebaseAuthentication(IAppleIDCredential appleIdCredential, string rawNonce, Action<FirebaseUser> firebaseAuthCallback)
{
    string identityToken = "";
    string authorizationCode = "";
    if (appleIdCredential.IdentityToken != null)
    {
        identityToken = Encoding.UTF8.GetString(appleIdCredential.IdentityToken, 0, appleIdCredential.IdentityToken.Length);
    }
    else
    {
        firebaseAuthCallback(null);//Return null if identityToken is null as we cannot proceed without it.
    }
    if (appleIdCredential.AuthorizationCode != null)//This will not be null for the first time, for all subsequent calls, it will return null.
    {
        authorizationCode = Encoding.UTF8.GetString(appleIdCredential.AuthorizationCode, 0, appleIdCredential.AuthorizationCode.Length);
    }
    else
    {
        //If Authorization code is null, proceed without it and make it the string null. Firebase does not require it.
        authorizationCode = null;
    }
    Credential credential = OAuthProvider.GetCredential("apple.com", identityToken, rawNonce, authorizationCode);//authorizationCode can be null
    auth.CurrentUser.LinkAndRetrieveDataWithCredentialAsync(credential).ContinueWithOnMainThread(task =>
    {
        if (task.IsCanceled)
        {
            //Task is cancelled
            firebaseAuthCallback(null);
        }
        else if (task.IsFaulted)
        {
            //Task is faulted
            Debug.LogError("linkAsync encountered an error: " + task.Exception);     
            firebaseAuthCallback(null);
           
        }
        else if (task.IsCompleted)
        {               
            firebaseAuthCallback(auth.CurrentUser);        
        }        
    });

}

[lupidan]

Yeah, my initial conclusion about this, is that apple just wants you to use that Authorization Code once, to get a refresh token every day, and check if the user is still valid or they have somehow revoked credentials. So it could make sense you only get it once the first time a user signs in ¿?

I’m glad to hear you sorted it out in your backend. Unfortunately there is not much we can do besides ask in the official Apple forum if this is a bug, or the expected behaviour 🤷

Closing this