Fatal Error (Invalid state: a login callback was received, but no login request was sent) - SwiftUI

Question

I'm getting a final error when trying to sign-in to my app. I asked a similar question here. Not sure what's happening, but an invalid login callback occurs after I authenticate.

I'm trying to sign-in with Apple using Firebase. The docs were updated just a month ago.

Here's my code:

import SwiftUI
import LocalAuthentication
import FirebaseAuth
import CryptoKit
import _AuthenticationServices_SwiftUI

final class SignInManager: ObservableObject {
    @Published var errorMessage = ""
    
    private var currentNonce: String?
    
    // 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
    }
    
    @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
    }
}

extension SignInManager {
    func handleSignInWithAppleRequest(_ request: ASAuthorizationAppleIDRequest) {
        request.requestedScopes = [.fullName, .email]
        let nonce = randomNonceString()
        currentNonce = nonce
        request.nonce = sha256(nonce)
    }
    
    func handleSignInWithAppleCompletion(_ result: Result<ASAuthorization, Error>) {
        if case .failure(let failure) = result {
            errorMessage = failure.localizedDescription
        }
        else if case .success(let success) = result {
            if let appleIDCredential = success.credential as? ASAuthorizationAppleIDCredential {
                guard let nonce = currentNonce else {
                    fatalError("Invalid state: a login callback was received, but no login request was sent.")
                }
                guard let appleIDToken = appleIDCredential.identityToken else {
                    print("Unable to fetdch identify token.")
                    return
                }
                guard let idTokenString = String(data: appleIDToken, encoding: .utf8) else {
                    print("Unable to serialize token string from data: \(appleIDToken.debugDescription)")
                    return
                }
                
                let credential = OAuthProvider.credential(withProviderID: "apple.com",
                                                          idToken: idTokenString,
                                                          rawNonce: nonce)
                Task {
                    do {
                        let result = try await Auth.auth().signIn(with: credential)
                        await updateDisplayName(for: result.user, with: appleIDCredential)
                    }
                    catch {
                        print("Error authenticating: \(error.localizedDescription)")
                    }
                }
            }
        }
    }
}

I thought it had something to do with the OAuth credential, but this seems configured correctly.

The .success case in handleSignInWithAppleCompletion succeeds, but afterwards immediately crashes the app.

Help.

When I print my .success case and when I print my currentNonce

Just use AuthenticationServices as import not that long name that starts with an underscore — lorem ipsum, Nov 30 '22 at 00:06

score 0 · Answer 1 · answered Dec 05 '22 at 06:54

Reposting answer from a previous question I asked differently, here.

Well, this took forever.

The solution is obvious in hindsight, but I was following the docs too slavishly. Always learn what the docs are trying to get across about how the software works versus trusting the documentation.

I just needed to initialize the currentNonce

Before: fileprivate var currentNonce: ? After: fileprivate var currentNonce = String()

Fatal Error (Invalid state: a login callback was received, but no login request was sent) - SwiftUI

1 Answers1