Swift 4 钥匙串 SecItemUpdate 错误状态代码 -50

Question

我正在尝试使用一些钥匙串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，这些功能工作正常，但我似乎无法让更新工作。

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)")
}
}
}
}
...

我不断收到错误状态 -50，表明传递给函数的一个或多个参数无效。我尝试通读文档，但想不出任何有效的方法。

提前谢谢你！

Answer 1

事实证明，我不得不从keychainQuery字典中删除最后两个键，因此它看起来像这样：

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)")
}
}
}
}
...