Duplicated anonymous users when session expired in Parse platforms - swift

if let cachedUser = PFUser.current() {
// proceed to save some objects
} else {
PFAnonymousUtils.logIn{ (user, error) in
// proceed to save some objects
if ((error as NSError).code == 209) {
// session expired, logout and call PFAnonymousUtils.logIn again later
PFUser.logOut()
}
}
}
For a simple Swift mobile app, we save data on parse backend anonymously. If there is session expiration error (1 year default on Parser server), we will have to do something about it or we wont be able to save anything anymore. We therefore logout and re-login again.
Once we logout and re-login again, this creates a second new User on the backend.
This creates a problem - we no longer have an accurate picture of the number of users on the backend.
What was wrong in the flow above? Is there a way to prevent duplicated anonymous user when handling expired session?

It is possible to increase the default session duration in your server configuration.
You can also add the code below to your server configuration...
expireInactiveSessions: false
This thread may provide further useful insights into this issue.

Related

Can you validate whether a user has been recently authenticated on Firebase (Swift)?

Is there a way to check if a user has recently authenticated on Firebase to avoid this message when trying to delete a user: "This operation is sensitive and requires recent authentication. Log in again before retrying this request."
I have been playing around trying to compare lastSignInDate (below) to current time but there seems to be a large margin of error on this which can cause problems:
firebase.auth().currentUser.metadata.lastSignInTime
Are there any functions that can return a simple boolean as to whether a user has recently authenticated so the user.delete() function will work properly?
Thanks so much!
The best way to do this is by checking if the response has an error, like so:
let user = Auth.auth().currentUser
user.delete { error in
if let error = error {
if (error.code == "auth/requires-recent-login") {
// The user's credentials are too old. Prompt Login screen.
}
} else {
// ...
}
}
According to Firebase Documentation, There's no other approach to this other than comparing the current date with firebase.auth().currentUser.metadata.lastSignInDate (Only if you have the Admin SDK on your app, but you most probably do not need that for enabling a user to delete themselves).

firebase error when deleting user account "This operation is sensitive and requires recent authentication. Log in again before retrying this request."

When I want to delete a firebase user account in my application, the operation passes normally if the user has recently logged but after a period of time if I try to delete the user I get this error
"This operation is sensitive and requires recent authentication. Log in again before retrying this request."
Normally the firebase refresh the user session automatically but I didn't find why he want the user to log again and even the value of Auth.auth().currentUser is not nil. Thank you for your help !
this is my code to delete the user account :
#objc func deleteAccountAction(){
self.showProgressView()
let user = Auth.auth().currentUser
let id=Auth.auth().currentUser?.uid
self.refProducts.child(id!).removeValue { error, _ in
if(error != nil){
print("firebase remove error")
print(error?.localizedDescription.description ?? nil)
self.dismissHUD(isAnimated: true)
}
else{
self.refUsers.child(id!).removeValue { error, _ in
if(error != nil){
print("firebase remove error")
print("error while deleting user from firebase: "+error!.localizedDescription)
self.dismissHUD(isAnimated: true)
}
else {
user?.delete { error in
if error != nil {
print("error while deleting user:" + error!.localizedDescription)
self.dismissHUD(isAnimated: true)
} else {
UserDefaults.standard.removeObject(forKey: "USER_UID")
UserDefaults.standard.synchronize
self.dismissHUD(isAnimated: true)
let nextVC = self.storyboard?.instantiateViewController(withIdentifier: "StartingViewController") as! StartingViewController
nextVC.isAccoundDeleted=true
GlobalVar.user=nil
self.navigationController?.pushViewController(nextVC, animated: true)
}
}
}
}
}
}
}
For certain sensitive operations (such as changing the user's password, or deleting the user account), Firebase requires that the user has recently signed in. If the user hasn't signed in recently when you try to perform such an operation, Firebase throws the exception you get.
When you get this exception, you should ask the user to re-enter their credentials, and retry the operation.
From the documentation on handling errors:
[Deleting a user account] is a security sensitive operation that requires a recent login from the user. This error indicates the user has not signed in recently enough. To resolve, reauthenticate the user by invoking reauthenticateWithCredential:completion: on FIRUser.
In addition to Frank van's answer, time span for that is 5 minutes. After 5 minutes of login you cannot do such operations.
you can refer FIRAuthErrorCode (check out error code 17014 : FIRAuthErrorCodeRequiresRecentLogin = 17014)
Here is a workaround:
Make a call to a cloud function that performs the user account deletion and sign out the client. You must ensure proper guards for this cloud function so that it is not maliciously used.
Show courtesy to your users. Offer them with a proper dialog showing that this is irreversible and all relevant user data will be deleted permanently. Only call the function if the user accepts the consequences.
PSA edit:
Although this approach will work, it will have an improper risk imposed on your user profile and data. The requirement to have the user sign in again for the delete account procedure serves a higher objective which is an additional layer of protection for the user account. By bypassing it as the solution suggests you are imposing a risk that another actor using the device will be able to delete the account without any additional checks. it is a procedure that is irreversible so if it was done by mistake then there is no way to go back.
What you can do (its probably the most easy way) is to save login and password of the user in the local storage when they log in first time (for example using AsyncStorage) and once they want to delete the account log them in again without needing them to reenter credentials shortly before you delete the account. They wont even noticed you logged them in again before deleting the account.
Im not a security expert but the password and email would be stored localy without access to the outside world so I do not see any concerns about security issues there.
Once you delete the app, the local storage is gone anyways, at least with AsyncStorage.
Once you logout a user and use another account, the new account credentials would overwrite the old ones from the local storage.

Is it a good practice to reload credentials before every request?

I'm working on an iOS app that works with a backend made in laravel, this api manage login and information exchange via JSON web tokens.
To prevent the user to access a web route with an expired token I check the user's credentials before every web call.
My question is, is it a good practice? Because when I started thinking about it the user is accessing twice the amount of times to my server.
For example this is the function to access they're information.
/// Get user's info form the database
///
/// - Parameter completed: Completition Block
func getInfo(completed: #escaping DownloadComplete){
let token = self.getToken()
print(self.getError())
if(token != nil && token != ""){
//Here is where I check credentials.
self.checkCredentials(completed: {
let url = "\(Base_URL)\(myInfo)\(self.getToken() ?? "")"
Alamofire.request(url, method: HTTPMethod.get).responseJSON { respone in
if let result = respone.result.value as? Dictionary<String, AnyObject>{
if let user = result["User"] as? Dictionary<String, AnyObject>{
var Info = Alumno()
if let id = user["id"] as? Int64!{
Info.id = id
}
...
self.userInfo = Info
completed()
}
}
}
})
}
}
The check credentials functions asks the server if the user's token is still valid and if it is it returns
{
"Status": "Success"
}
My answer assumes your server validates the token, and you are not relying on the app to validate the token.
With that assumption, I think it depends on what you can do if the token is expired.
If the only thing you can do is prompt the user to sign in again, then I would probably just make the web request and handle the 401 Not Authorized.
However, if you have the ability to silently refresh the user's token, you may want to preemptively refresh the token if is close to expiring.
In my application, before every web request the app checks if the user's access token will expire within the next 3 minutes, and if so, attempts to refresh it before making the request. If the refresh is successful, the web request is made with the new access token. If the refresh fails, the web request is not made and the app prompts the user to sign in instead. If for any reason the web request still fails after that with 401, the app prompts the user to sign in.
I would do it like once every time the user opens the app not every call.
Other options:
You could also give them a code that they enter that's good for so long.
You could have them sign in when they first download the app. Then they would always be logged in. Then when the token is expired a little popup would say "Something Something Something"

Parse user not updating for just one specific user

I was wondering if anyone has seen a case where Parse User table doesn't update for a specific user. I have a pretty simple code:
PFUser.current()?["TorF"] = true
PFUser.current()?.saveInBackground(block: { (success, error) in
if error != nil {
print(error)
} else {
}
})
I have checks in other places of the app regarding whether there is a current PFUser, and my database shows that the user is logged in and PFUser.current() is correctly assigned to this user. The simple operation above works for all other users except for one specific user. Has anyone encountered something like this?
I found out that this was happening because the user had changed his password and therefore invalidated his access token. The place to check for whether the user's access token is valid is via Graph request.

Swift : How to check if Facebook access token has expired?

I'm currently using
if FBSDKAccessToken.currentAccessToken() != nil {
//Do Something
}
else {
//Passing the access token to my server
}
to check if a user is already logged in. But the problem in this approach is if a user opens my app after long time the currentAccessToken might have expired but since it is not nil it will send the expired token to the server.
How can I put a check if currentAccessToken is valid or not? I'm using version 2.4 of FBSDK
I think you may request https://graph.facebook.com/me?access_token=TOKEN
If token is not valid you will get oauth error in json response, otherwise you will get some info about user.
But better, for my mind, do the same on server side.