ios swift keyChainMabager for GenericPassword

ios swift keyChainMabager

class KeyChainManager {
    
    static func saveGenericPassword(service:String, account:String, password:String) -> Void {
        let account = userNameTextField.text
        let passwordUtf8 = password.data(using: String.Encoding.utf8)!
        let addquery: [String: Any] = [kSecClass as String: kSecClassGenericPassword,
                                       kSecAttrAccount as String: account!,
                                       kSecAttrService as String: service ,
                                       kSecValueData as String: passwordUtf8!]
        
        let status = SecItemAdd(addquery as CFDictionary, nil)
        guard status == errSecSuccess else {
            os_log("%{public}@", type: .debug, "Error saving to keychain \(status)")
            return
        }
        os_log("%{public}@", type: .debug, "success saving to keychain \(status)")
    }
    
    static func retrieveGenericPassword(service:String, account:String, password:String) -> String {
        let user = account
        let getquery: [String: Any] = [kSecClass as String: kSecClassGenericPassword,
                                       kSecAttrAccount as String: user!,
                                       kSecAttrService as String: service,
                                       kSecMatchLimit as String: kSecMatchLimitOne,
                                       kSecReturnAttributes as String: true,
                                       kSecReturnData as String: true]
        
        var item: CFTypeRef?
        let status = SecItemCopyMatching(getquery as CFDictionary, &item)
        
        
        guard status != errSecItemNotFound else {
            os_log("%{public}@", type: .debug, "Error: \(KeychainError.noPassword)")
            return
        }
        guard status == errSecSuccess else {
            os_log("%{public}@", type: .debug, "unhandledError: \(KeychainError.unhandledError(status: status))")
            return
        }
        
        
        guard let existingItem = item as? [String : Any],
            let passwordData = existingItem[kSecValueData as String] as? Data,
            let password = String(data: passwordData, encoding: String.Encoding.utf8),
            let accountRetrieved = existingItem[kSecAttrAccount as String] as? String
            else {
                os_log("%{public}@", type: .debug, "unexpectedPasswordData: \(KeychainError.unexpectedPasswordData)")
                return
            }
        return password
    }

}