How to Sign Out of Apple After Being Authenticated

Question

My app has a "Sign in with the Apple" account feature. I am wondering if there is sign out feature from the Apple account.

I tried the below but doesn't get success

    let request = ASAuthorizationAppleIDProvider().createRequest()

    request.requestedOperation = .operationLogout

    let authorizationController = ASAuthorizationController(authorizationRequests: [request])

    authorizationController.performRequests()

Answer 1

Apple only allows currently for the user to perform a signout (iOS/watchOS/tvOS) or shown as a revoke of permissions to us. They recommend you get the state of the credentials before use to check for revoke and if that has occurred to delete any local information (Remove the user identifier where ever you have it stored) (And possibly change UI if needed; For example like showing login view).

        let appleIDProvider = ASAuthorizationAppleIDProvider()
    appleIDProvider.getCredentialState(forUserID: KeychainItem.currentUserIdentifier) { (credentialState, error) in
        switch credentialState {
        case .authorized:
            // The Apple ID credential is valid.
            break
        case .revoked:
            // The Apple ID credential is revoked.
            break
        case .notFound:
            // No credential was found, so show the sign-in UI.
            break
        default:
            break
        }
    }

You could provide a prompt to the user on signout guiding them to revoke in their device's settings as well and listen for the change notification.

Answer 2

You need to delete the existing item from the keychain.

This is my sample code, using Apple sample code.
You can get sample code from Apple

Apple recommend you get the state of the credentials before use to check for revoke and if that has occurred to delete any local information

struct KeychainItem {

    
    init(service: String, account: String, accessGroup: String? = nil) {
        self.service = service
        self.account = account
        self.accessGroup = accessGroup
    }

    static func deleteUserIdentifierFromKeychain() {
        do { //please change service id to your bundle ID 
            try KeychainItem(service: "com.example.apple-samplecode", account: "userIdentifier").deleteItem()
        } catch {
            print("Unable to delete userIdentifier from keychain")
        }
    }

   func deleteItem() throws {
        // Delete the existing item from the keychain.
        let query = KeychainItem.keychainQuery(withService: service, account: account, accessGroup: accessGroup)
        let status = SecItemDelete(query as CFDictionary)
        
        // Throw an error if an unexpected status was returned.
        guard status == noErr || status == errSecItemNotFound else { throw KeychainError.unhandledError }
    }

keychainQuery

keychainQuery is from apple sample code.

    
    private static func keychainQuery(withService service: String, account: String? = nil, accessGroup: String? = nil) -> [String: AnyObject] {
        var query = [String: AnyObject]()
        query[kSecClass as String] = kSecClassGenericPassword
        query[kSecAttrService as String] = service as AnyObject?
        
        if let account = account {
            query[kSecAttrAccount as String] = account as AnyObject?
        }
        
        if let accessGroup = accessGroup {
            query[kSecAttrAccessGroup as String] = accessGroup as AnyObject?
        }
        
        return query
    }