iOS Keychain won't add queries with hardcoded strings - ios

Question

I am following the Apple documentation for adding a password to the keychain located here -> https://developer.apple.com/documentation/security/keychain_services/keychain_items/adding_a_password_to_the_keychain
When I run the following code it works as expected and the status comes back as 0.
let credentials = Credentials(username: "testUserName", password: "testPassword")
let server = "www.example.com"
let account = credentials.username
let password = credentials.password.data(using: String.Encoding.utf8)!
let query: [String: Any] = [kSecClass as String: kSecClassInternetPassword,
kSecAttrAccount as String: account,
kSecAttrServer as String: server,
kSecValueData as String: password]
let status = SecItemAdd(query as CFDictionary, nil)
print(status)
When I modify the code with hardcoded strings it fails with a status of -50.
let credentials = Credentials(username: "testUserName", password: "testPassword")
let server = "www.example.com"
//let account = credentials.username
//let password = credentials.password.data(using: String.Encoding.utf8)!
let account = "testUserName"
let password = "testPassword"
let query: [String: Any] = [kSecClass as String: kSecClassInternetPassword,
kSecAttrAccount as String: account,
kSecAttrServer as String: server,
kSecValueData as String: password]
let status = SecItemAdd(query as CFDictionary, nil)
print("Keychain Save Status: \(status)")
Can someone explain this to me? I also tried explicitly setting the strings to utf8 format with let account = "testUsername".utf8. It doesn't make sense to me that this would fail if the value is a valid string.
Also does anyone have the link to the status code descriptions? I found the descriptions but it doesn't give the associated number code https://developer.apple.com/documentation/security/1542001-security_framework_result_codes

Answer 1

YES, I know my answer on the other track. As per my own experience, I'm using below keychain wrapper in Swift and Objective - C. Happy and Lazy Coding! :)
Swift - Locksmith - https://github.com/matthewpalmer/Locksmith
Objective-C - SSKeychain - https://github.com/samsoffes/sskeychain
//Generate Device UUID
func CreateApplicationDeviceUUID() -> String{
let DeviceUUID = NSUUID().uuidString
print("DeviceUUD==\(DeviceUUID)")
return DeviceUUID
}
//Retrive Device Unique UUID
let keyChainID = Locksmith.loadDataForUserAccount(userAccount: Bundle.main.object(forInfoDictionaryKey:"CFBundleName") as! String)
let retriveuuid = keyChainID?[RDGlobalFunction.deviceAppUUID] //RDGlobalFunction.deviceAppUUID is a Key of KeyChain Value Storage
if(retriveuuid == nil){
let uuid = CreateApplicationDeviceUUID()
do{
try Locksmith.saveData(data: [RDGlobalFunction.deviceAppUUID : uuid], forUserAccount: Bundle.main.object(forInfoDictionaryKey: "CFBundleName") as! String) //Locksmith - SSkeyChain Thirdparty KeyChain Wrapper
}catch{
//Catch Error
}
}
Other Reference Link:
https://www.raywenderlich.com/179924/secure-ios-user-data-keychain-biometrics-face-id-touch-id
https://medium.com/ios-os-x-development/securing-user-data-with-keychain-for-ios-e720e0f9a8e2
https://code.tutsplus.com/tutorials/securing-ios-data-at-rest--cms-28528

Answer 2

I figured out that if I change
let password = "testPassword"
to
let password = "testPassword".data(using: String.Encoding.utf8)!
then it will work as expected. It seems that the kSecValueData parameter must be a utf8 encoded string.