Logout user before deleting via parse cloud code - parse-platform

I am currently writing a background job that deletes a (for inappropriate content, or violation of the license agreement) flagged user and all his content.
The problem is that if the user doesn’t logout manually, he can still use the app (and even create new content) even if his account does not exist anymore.
So is there a way to logout a specific user via cloud code or destroy his session?

Content creation in your Parse app isn't limited to a logged in and valid user by default, Parse does not know that you might want to limit content creation to valid and logged in users or not, some developers might even not use user accounts at all etc.
It is up to you to ensure that the client/user making the request is allowed to do so. This can either be enforced by using an ACL on your classes or by using a beforeSave function in Cloud Code. I prefer Cloud Code and it is pretty straight forward to enforce a valid user there.
Parse.Cloud.beforeSave("YourClass", function(request,response) {
if (request.user == null) {
response.error();
} else {
response.success();
}
});

Related

Is it safe firebase-messaging-sw.js in public folder [duplicate]

The Firebase Web-App guide states I should put the given apiKey in my Html to initialize Firebase:
// TODO: Replace with your project's customized code snippet
<script src="https://www.gstatic.com/firebasejs/3.0.2/firebase.js"></script>
<script>
// Initialize Firebase
var config = {
apiKey: '<your-api-key>',
authDomain: '<your-auth-domain>',
databaseURL: '<your-database-url>',
storageBucket: '<your-storage-bucket>'
};
firebase.initializeApp(config);
</script>
By doing so, the apiKey is exposed to every visitor.
What is the purpose of that key and is it really meant to be public?
The apiKey in this configuration snippet just identifies your Firebase project on the Google servers. It is not a security risk for someone to know it. In fact, it is necessary for them to know it, in order for them to interact with your Firebase project. This same configuration data is also included in every iOS and Android app that uses Firebase as its backend.
In that sense it is very similar to the database URL that identifies the back-end database associated with your project in the same snippet: https://<app-id>.firebaseio.com. See this question on why this is not a security risk: How to restrict Firebase data modification?, including the use of Firebase's server side security rules to ensure only authorized users can access the backend services.
If you want to learn how to secure all data access to your Firebase backend services is authorized, read up on the documentation on Firebase security rules. These rules control access to file storage and database access, and are enforced on the Firebase servers. So no matter if it's your code, or somebody else's code that uses you configuration data, it can only do what the security rules allow it to do.
For another explanation of what Firebase uses these values for, and for which of them you can set quotas, see the Firebase documentation on using and managing API keys.
If you'd like to reduce the risk of committing this configuration data to version control, consider using the SDK auto-configuration of Firebase Hosting. While the keys will still end up in the browser in the same format, they won't be hard-coded into your code anymore with that.
Update (May 2021): Thanks to the new feature called Firebase App Check, it is now actually possible to limit access to the backend services in your Firebase project to only those coming from iOS, Android and Web apps that are registered in that specific project.
You'll typically want to combine this with the user authentication based security described above, so that you have another shield against abusive users that do use your app.
By combining App Check with security rules you have both broad protection against abuse, and fine gained control over what data each user can access, while still allowing direct access to the database from your client-side application code.
Building on the answers of prufrofro and Frank van Puffelen here, I put together this setup that doesn't prevent scraping, but can make it slightly harder to use your API key.
Warning: To get your data, even with this method, one can for example simply open the JS console in Chrome and type:
firebase.database().ref("/get/all/the/data").once("value", function (data) {
console.log(data.val());
});
Only the database security rules can protect your data.
Nevertheless, I restricted my production API key use to my domain name like this:
https://console.developers.google.com/apis
Select your Firebase project
Credentials
Under API keys, pick your Browser key. It should look like this: "Browser key (auto created by Google Service)"
In "Accept requests from these
HTTP referrers (web sites)", add the URL of your app (exemple: projectname.firebaseapp.com/* )
Now the app will only work on this specific domain name. So I created another API Key that will be private for localhost developement.
Click Create credentials > API Key
By default, as mentioned by Emmanuel Campos, Firebase only whitelists localhost and your Firebase hosting domain.
In order to make sure I don't publish the wrong API key by mistake, I use one of the following methods to automatically use the more restricted one in production.
Setup for Create-React-App
In /env.development:
REACT_APP_API_KEY=###dev-key###
In /env.production:
REACT_APP_API_KEY=###public-key###
In /src/index.js
const firebaseConfig = {
apiKey: process.env.REACT_APP_API_KEY,
// ...
};
I am not convinced to expose security/config keys to client. I would not call it secure, not because some one can steal all private information from first day, because someone can make excessive request, and drain your quota and make you owe to Google a lot of money.
You need to think about many concepts from restricting people not to access where they are not supposed to be, DOS attacks etc.
I would more prefer the client first will hit to your web server, there you put what ever first hand firewall, captcha , cloudflare, custom security in between the client and server, or between server and firebase and you are good to go. At least you can first stop suspect activity before it reaches to firebase. You will have much more flexibility.
I only see one good usage scenario for using client based config for internal usages. For example, you have internal domain, and you are pretty sure outsiders cannot access there, so you can setup environment like browser -> firebase type.
The API key exposure creates a vulnerability when user/password sign up is enabled. There is an open API endpoint that takes the API key and allows anyone to create a new user account. They then can use this new account to log in to your Firebase Auth protected app or use the SDK to auth with user/pass and run queries.
I've reported this to Google but they say it's working as intended.
If you can't disable user/password accounts you should do the following:
Create a cloud function to auto disable new users onCreate and create a new DB entry to manage their access.
Ex: MyUsers/{userId}/Access: 0
exports.addUser = functions.auth.user().onCreate(onAddUser);
exports.deleteUser = functions.auth.user().onDelete(onDeleteUser);
Update your rules to only allow reads for users with access > 1.
On the off chance the listener function doesn't disable the account fast enough then the read rules will prevent them from reading any data.
I believe once database rules are written accurately, it will be enough to protect your data. Moreover, there are guidelines that one can follow to structure your database accordingly. For example, making a UID node under users, and putting all under information under it. After that, you will need to implement a simple database rule as below
"rules": {
"users": {
"$uid": {
".read": "auth != null && auth.uid == $uid",
".write": "auth != null && auth.uid == $uid"
}
}
}
}
No other user will be able to read other users' data, moreover, domain policy will restrict requests coming from other domains.
One can read more about it on
Firebase Security rules
While the original question was answered (that the api key can be exposed - the protection of the data must be set from the DB rulles), I was also looking for a solution to restrict the access to specific parts of the DB.
So after reading this and some personal research about the possibilities, I came up with a slightly different approach to restrict data usage for unauthorised users:
I save my users in my DB too, under the same uid (and save the profile data in there). So i just set the db rules like this:
".read": "auth != null && root.child('/userdata/'+auth.uid+'/userRole').exists()",
".write": "auth != null && root.child('/userdata/'+auth.uid+'/userRole').exists()"
This way only a previous saved user can add new users in the DB so there is no way anyone without an account can do operations on DB.
Also adding new users is posible only if the user has a special role and edit only by admin or by that user itself (something like this):
"userdata": {
"$userId": {
".write": "$userId === auth.uid || root.child('/userdata/'+auth.uid+'/userRole').val() === 'superadmin'",
...
EXPOSURE OF API KEYS ISN'T A SECURITY RISK BUT ANYONE CAN PUT YOUR CREDENTIALS ON THEIR SITE.
Open api keys leads to attacks that can use a lot resources at firebase that will definitely cost your hard money.
You can always restrict you firebase project keys to domains / IP's.
https://console.cloud.google.com/apis/credentials/key
select your project Id and key and restrict it to Your Android/iOs/web App.
It is oky to include them, and special care is required only for Firebase ML or when using Firebase Authentication
API keys for Firebase are different from typical API keys:
Unlike how API keys are typically used, API keys for Firebase services are not used to control access to backend resources; that can only be done with Firebase Security Rules. Usually, you need to fastidiously guard API keys (for example, by using a vault service or setting the keys as environment variables); however, API keys for Firebase services are ok to include in code or checked-in config files.
Although API keys for Firebase services are safe to include in code, there are a few specific cases when you should enforce limits for your API key; for example, if you're using Firebase ML or using Firebase Authentication with the email/password sign-in method. Learn more about these cases later on this page.
For more informations, check the offical docs
I am making a blog website on github pages. I got an idea to embbed comments in the end of every blog page. I understand how firebase get and gives you data.
I have tested many times with project and even using console. I am totally disagree the saying vlit is vulnerable.
Believe me there is no issue of showing your api key publically if you have followed privacy steps recommend by firebase.
Go to https://console.developers.google.com/apis
and perfrom a security steup.
You should not expose this info. in public, specially api keys.
It may lead to a privacy leak.
Before making the website public you should hide it. You can do it in 2 or more ways
Complex coding/hiding
Simply put firebase SDK codes at bottom of your website or app thus firebase automatically does all works. you don't need to put API keys anywhere

Allow admin user to login as other users

Is there any way to login other users account for admin user ?
Currently authentication based on Meteor Accounts
I saw this post but didn't working at all now.
The feature is important for us because when user have problem in system then admin need to see it this by simulating user account.
Thanks in advance.
It seems you want to impersonate a user. This means that you want to have Meteor.userId (or this.userId depending on context) reflect the _id of a specific user both on the client and the server.
afaict the only way to do this is to login as the user. Presumably you don't want to ask the user for their password so you have a couple of choices:
Save their existing password, replace it (temporarily) with a password of your choosing, then after you're done impersonating their account, restore their existing password.
You probably don't want to ask the user for their password and you don't need to. All you need to do is set aside Meteor.user.findOne(userId).services.password.bcrypt, then reset the password to your temporary value, then restore the original bcrypt value later.
The downside is that the original user would not be able to login while you are logged-in. Plus it's really hacky.
Extend Meteor's Accounts package to provide impersonation capability in a more elegant manner.
You might also look at validateLoginAttempt. The docs are unclear as to whether a failed login attempt could be overridden with a successful one but if it could then that would provide another pathway to solve your problem.
Instead of logging in as the users, which requires their password and which is a total no-no, you may use rather alanning:roles and allow the admin to assign the role of any user in order to draw views based the user's role.
This requires a well designed role system.
As a plus you could then at least load the documents associated with the user who you want to support.
This requires a well designed document and data model.
But generally spoken you should rather focus on writing good tests (test driven development) for components as unit tests, integration tests and UI tests.
This will reduce the need to manually view the app as an end user a lot.
The most common end user problems can be reduced by creating a good knowledge base like a wiki or video tutorials.
Even if then an error occurs in the end user side, I would rather try to implement a well designed error log that allows users automatically create tickets on error which also include the error stack.
All the above methods are to be favored before logging in AS THE USER.
As #Jankpunkt has already mentioned alanning-roles I can add something you can use without installing any external package.
Just keep a type key in the profile object of the users collection. Then define some types like 1 for super-admin, 2 for admin, 3 for general etc. Then check the authorisation of particular action by checking the value of user.profile.type key.
Caveats: Make sure you are checking the type in server side. By default profile field is writable from the client end, so if you are putting type field in the profile object make sure that you are not allowing users to modify users collection in the client end.
Here is how to restrict client end update in users collection:
Meteor.users.deny({
update() { return true; }
});
Read more on roles and permissions here:
https://guide.meteor.com/accounts.html#roles-and-permissions

Disable requests to Parse-server without Master Key

Is it possible to disable requests sent to Parse without a master key? I'd like to only access Parse through my custom backend and not give users direct access. Does public 'read' set on the User class mean that anyone can read the records in that class? If so, why is this a default - wouldn't that be against good security practices?
Thanks,
Daniel
Public read means that anyone with your api key can read the user collection from your parse server. Api key is not the best approach to protect your app because anybody can know it by putting "sniffing" your network requests.
In order to protect and provide access you can protect your objects with ACL's which allows you to create access for specific user (who is logged in) or to specific role. So you have couple of options:
Create a master user - each user must have username and password and when you create your parse objects make sure that only this specific user create/read/delete and update them. You must only to make sure that when you create an object you create ACL for this user so only this user will be able to modify and read the object. You can read more about parse-server security and ACL's in here: http://docs.parseplatform.org/rest/guide/#security
Using parse cloud code - In cloud code there is a nice feature of useMasterKey which provide full access to any object of parse-server so for each operation that you run (via JS SDK) you can also set the useMasterKey to true and then parse-server will ignore all the ACL's and will execute the query for you. The useMasterKey feature work only in cloud code context so it's safe. If you want to provide additional level of security you can run the cloud code function with your master user (from section 1) and check inside the cloud code for the user session so if the session is empty then you can return an error.
You can read more about cloud code in here: http://docs.parseplatform.org/cloudcode/guide/
This is the code which validate the user session:
if (!request.user || !request.user.get("sessionToken")) {
response.error("only logged in users are allowed to use this service");
return;
}

Creating a service for user (S4U) token

The Windows Task Scheduler can create tasks that run with the account of a particular user, without storing the user password. They call it "S4U", service for user. This should work something like the scheduler creates such a token for the current user and can use it to run the scheduled process under that user account. They claim that it cannot access network or encrypted resources with this system. The scheduler itself runs with the SYSTEM account for it to work. Here's an article that describes it. The relevant quote from it:
TASK_LOGON_S4U is yet another option that provides a more secure
alternative. It takes advantage of a service for user (S4U) logon to
run the task on behalf of the specified user, but without having to
store the password. Since the Task Scheduler runs within the local
system account, it can create a S4U logon session and receive a token
that can not only be used for identification, but also for
impersonation on the local computer. Normally a S4U token is only good
for identification.
I need to use this authentication scheme in my application, but can't let the Task Scheduler do it but need to do it myself, because I need it for any number of accounts. Whenever a user registers a task with my application, any followup tasks must run under the same user. But since they cannot overlap, I need to do the serialisation myself.
I cannot find any information about this "S4U" thing. How could I implement it in my application? C# preferred, but WINAPI and C is okay.
Update: This is what I've tried, and it doesn't work.
// The WindowsIdentity(string) constructor uses the new
// Kerberos S4U extension to get a logon for the user
// without a password.
WindowsIdentity wi = new WindowsIdentity(identity);
WindowsImpersonationContext wic = null;
try
{
wic = wi.Impersonate();
// Code to access network resources goes here.
}
catch()
{
// Ensure that an exception is not propagated higher in the call stack.
}
finally
{
// Make sure to remove the impersonation token
if( wic != null)
wic.Undo();
}
But I've got the impression now, that you can't just say you want to be a certain user. Not even as System. You need to be logged in as that user and can generate some token that allows you to become that user later again, without the password. So this must be a two-step thing, first I need to get the token and store it on disk; later I can use that token to impersonate. None of the examples explains this.
"The computer may not be joined to the domain"
S4U requires access to a KDC. S4U is actually two protocols. S4U2Self and S4U2Proxy. What it is doing is using an addition to Kerberos to get service tickets for a user, but that account that goes and gets the ticket has to have a special delegation enabled on it. See here for this set up.
But unless you are actually letting the process die etc, why not just get the users service ticket or TGT? Is your application local or is it a service running remote to the user?
Task scheduler needs to go get a new one because a service ticket isn't valid forever. Or in some delegation schemes the user hasn't passed a service ticket to the Application Server and then the AS goes and requests and service ticket via S4U2Self, and then uses that service ticket to request a ticket to a second service via S4U2Proxy.

Does Flexi-auth support third-party login? if yes how to do?

I'm using Flexi-auth library for user authentication with codeigniter,
General login is working properly.
Does Flexi-auth support third-party(google/yahoo) login? if yes how to do?
I've looked through the documentation for a while and can't find an official way to actually accomplish this. However, from looking through the code I found that the user is actually logged in through a call to a function called set_login_sessions. The function is private to the Flexi_auth_model class, however.
If you're absolutely sure you wouldn't introduce any vulnerabilities you aren't already taking care of some other way, you can define your own method along the lines of:
public function login_3rd($identity = FALSE) {
// Check logins, activation, suspensions etc like `Flexi_auth_model::login`
// Confirm the login with the OAuth service
// Query the DB to get the user
set_login_sessions($user, FALSE);
}
Most of this is pretty much just like the login function but adjusted for 3rd party authentication.
It is important that you set the $logged_in_via_password argument to FALSE when calling set_login_sessions. There are some sensitive areas on a web application (like withdrawing money or something) that should require the user to have entered the password before going through. This prevents a friend who re-opens your browser (or someone who gets your session via malicious means) from having access to certain things. Flexi-auth provides a is_logged_in_via_password that allows you to check this. But it won't work if we don't tell it the truth.

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