ios - Swift 4钥匙串(keychain)SecItemUpdate错误状态码-50

我正在尝试使用一些密钥链代码来安全持久地存储一些敏感数据。我有保存和读取数据的功能，这些功能工作良好，但我似乎无法让更新的工作。

let kSecClassValue = NSString(format: kSecClass)
let kSecAttrAccountValue = NSString(format: kSecAttrAccount)
let kSecValueDataValue = NSString(format: kSecValueData)
let kSecClassGenericPasswordValue = NSString(format: kSecClassGenericPassword)
let kSecAttrServiceValue = NSString(format: kSecAttrService)
let kSecMatchLimitValue = NSString(format: kSecMatchLimit)
let kSecReturnDataValue = NSString(format: kSecReturnData)
let kSecMatchLimitOneValue = NSString(format: kSecMatchLimitOne)


public class KeychainService: NSObject {
    class func updatePassword(service: String, account:String, data: String) {
        if let dataFromString: Data = data.data(using: String.Encoding.utf8, allowLossyConversion: false) {
            // Instantiate a new default keychain query
            let keychainQuery: NSMutableDictionary = NSMutableDictionary(objects: [kSecClassGenericPasswordValue, service, account, kCFBooleanTrue, kSecMatchLimitOneValue], forKeys: [kSecClassValue, kSecAttrServiceValue, kSecAttrAccountValue, kSecReturnDataValue, kSecMatchLimitValue])
            let status = SecItemUpdate(keychainQuery as CFDictionary, [kSecValueDataValue:dataFromString] as CFDictionary)
            if (status != errSecSuccess) {
                if let err = SecCopyErrorMessageString(status, nil) {
                    print("Read failed: \(err)")
                    print("status: \(status)")
                }
            }
        }
    }
...

我经常得到错误状态-50，表示传递给函数的一个或多个参数无效。我试着通读那些文件，但什么都没想到。
提前谢谢你！

最佳答案

结果，我不得不从keychainQuery字典中删除最后两个键，所以看起来像这样：

public class KeychainService: NSObject {
    class func updatePassword(service: String, account:String, data: String) {
        if let dataFromString: Data = data.data(using: String.Encoding.utf8, allowLossyConversion: false) {
            // Instantiate a new default keychain query
            let keychainQuery: NSMutableDictionary = NSMutableDictionary(objects: [kSecClassGenericPasswordValue, service, account], forKeys: [kSecClassValue, kSecAttrServiceValue, kSecAttrAccountValue])
            let status = SecItemUpdate(keychainQuery as CFDictionary, [kSecValueDataValue:dataFromString] as CFDictionary)
            if (status != errSecSuccess) {
                if let err = SecCopyErrorMessageString(status, nil) {
                    print("Read failed: \(err)")
                    print("status: \(status)")
                }
            }
        }
    }
...