Save and retrieve value via KeyChain

Question

I\'m trying to store an Integer and retrieve it using KeyChain.

This is how I save it:

func SaveNumberOfImagesTaken()
    {
        let key = \"IMAGE         


        

Answer 1

I tried to make it as simple as possible.

fileprivate class KeychainService {

  static func updatePassword(_ password: String, serviceKey: String) {
    guard let dataFromString = password.data(using: .utf8) else { return }

    let keychainQuery: [CFString : Any] = [kSecClass: kSecClassGenericPassword,
                                           kSecAttrService: serviceKey,
                                           kSecValueData: dataFromString]
    SecItemDelete(keychainQuery as CFDictionary)
    SecItemAdd(keychainQuery as CFDictionary, nil)
  }

  static func removePassword(serviceKey: String) {

    let keychainQuery: [CFString : Any] = [kSecClass: kSecClassGenericPassword,
                                           kSecAttrService: serviceKey]

    SecItemDelete(keychainQuery as CFDictionary)
  }

  static func loadPassword(serviceKey: String) -> String? {
    let keychainQuery: [CFString : Any] = [kSecClass : kSecClassGenericPassword,
                                           kSecAttrService : serviceKey,
                                           kSecReturnData: kCFBooleanTrue,
                                           kSecMatchLimitOne: kSecMatchLimitOne]

    var dataTypeRef: AnyObject?
    SecItemCopyMatching(keychainQuery as CFDictionary, &dataTypeRef)
    guard let retrievedData = dataTypeRef as? Data else { return nil }

    return String(data: retrievedData, encoding: .utf8)
  }

  static func flush()  {
    let secItemClasses =  [kSecClassGenericPassword]
    for itemClass in secItemClasses {
      let spec: NSDictionary = [kSecClass: itemClass]
      SecItemDelete(spec)
    }
  }
}