How to set the Principal in an ASP.Net app - asp.net

I am writing a web app for a client. Users will have a one-time key that they will use to initially identify themselves to the app. Once the app verifies that the key is valid it will take them to a page where they can create a normal account to use for all subsequent logins. The create-account page should only be accessible after entering the key and shouldn't be accessible otherwise. I.e, it shouldn't be accessible to users logged in with a normal account.
This is asp.net 3.0 using a custom membership provider.
My plan is to create a temporary account based on the key and authenticate the user with that account. This allows them access to the create-user page (which is protected with a location tag ) where they can create the formal account. I then authenticate them with their new account and delete the temporary account.
The flow is: the user goes to a page where they enter the key. If the key is valid I create the temporary account, call FormsAuthentication.SetAuthCookie, and redirect to the create-account page. This all works, although it seems a little complicated.
The problem is that the create-user page is available to any authenticated user; I only want it available during the time between entering the key and creating the formal account. So I thought I'd create a special role for the temporary account and make the create-user page accessible only to that role and none other. I created my own Principal object with a special role and tried setting it when I authenticate the temporary account but I can't get that to work.
I'm really hoping I don't have to write a custom role provider just to do this.
How can I make this work? There's gotta be a simpler way!

Why not simply create the real account when they enter the key. Assign it some random name and then let them change the name and other details. Then you don't need the create user page, just the enter key page and an account details editing page. If you're concerned about getting the account details filled in, you could set it up (perhaps via code on a MasterPage) so that incomplete accounts always get redirected to the edit details page until the details are entered.
Or, you could have them enter the required details in addition to the key code on the enter key page and simply use those details when creating the account.

My advice would be to avoid the use of temporary accounts when validating the user. Instead, generate your own logic for validating the sign-up key. Then, at the head of the page, you can check whether the user is an authenticated user (SetAuthCookie has been called) and jump to a different page if this is true.
You may even be able to change the page access to forbid this page to authenticated users (I know you can disable accounts for unauthenticated users but I'm not sure if you can go the other direction).
The key, though, is to avoid relying on the membership provider when, in fact, the user is not yet a member!

Assign an "incomplete" role when authenticating against the temporary token, then restrict access to only that role... when the account is created, send them to a re-login page (terminating the authentication token). This will simplify your security model.

Related

Firebase subaccounts

I'm currently building a POS/Store admin app, when a user gets into my app, the Owner of the store will then be asked to login only once for setup purpose (e.g. a new machine), the app will then display a list of staffsName that has already been added by this owner, and then everytime a staff wants to start a new transaction, he/she will only need to click on his/her name, then enter his/her 4-digit pincode to 'login' and process the transaction.
How do i go about achieving this?
I was thinking of using firebase auth for the 'login' of the staff, but then when i log in using the staff credential, I will lose access to the uid of the owner, which is needed to access the owner's store data such as his/her products.
i'm also thinking of using firestore to store the 4digit pincode, but then i'm also concerned about security
There are multiple ways you can approach this, one where you utilize the email login by simply appending a fake domain to the username to create a valid email domain. This user account could be the designated 'user' in question, or utilize credentials inside custom claims or hidden in a database that allows the client or server (depending on your preference) to then log in as the user.
Moreover if you want the manager to login once you can add Authentication State Persistence to specify whether a signed in user should be indefinitely persisted until explicit sing out, page reload etc.
Another approach requires the user also to have a valid auth that is not an email password and you link your pin auth to that main account with Firebase Auth Linking per the documentation: https://firebase.google.com/docs/auth/web/account-linking.
This does however require that the user be registered from an auth provider such as Google, Twitter, Apple, etc. then the user will have to activate this link by logging in for authentication purposes. This can in theory be automatically generated and processed without the user knowing.
It is a long way around it since this is essentially a custom solution but it does create the flow you are looking for without having to use a custom auth provider.

How do I allow a role insert into a table (for signup), but after that deny further inserts for that user?

That's my question. I am using Hasura, and defining 'user' permissions.
Users are of course allowed to modify their own information, and not allowed to insert new records into my users table.
But when they signup, they should be allowed to insert themselves. So how can I define this permission?
To make my scenario more clear:
I have a React app, that uses an external OpenID provider. So a new user signs up there, and the provider returns a JWT to my app, containing a user I've never seen before.
My app does not know that, it just uses the access token to send to the Hasura backend to retrieve further info about this user, using the 'user' role. But it uses a query which will automatically insert the user if not found.
There's really not a safe way to allow sign-ups without involving a backend service. It is a very bad idea to allow anonymous inserts into your user table, even if you added a unique constraint against a user ID or email address.
If you have the option of using NextJS, see the Hasura example for configuring NextAuth. This works by configuring your app with a protected API route that uses your Hasura app's ADMIN_SECRET to insert new users who have authenticated with a third-party.
If NextJS isn't an option, Hasura's Auth0 example similarly uses a callback method to insert an authenticated user if they don't exist.
In the user table, for the user role, you need to add a permission with custom check. And the check should be user_id equals x-hasura-user-id.
{"id":{"_eq":"x-hasura-user-id"}}
For non-logged-in users, leverage the anonymous role by setting the permissions that make sense for your use case: https://hasura.io/docs/1.0/graphql/manual/auth/authorization/common-roles-auth-examples.html#anonymous-not-logged-in-users
Edit after the comment:
Ah, I see. When the user comes to your app, your app goes and retrieves some data that it expects every user should have (for example perhaps the user info store on the user table). But since it's a new user, this info is not there.
At this point, your React app knows that:
there's someone with a legitimately signed JWT cookie (use a library to verify the signature) and
there's no user info from the backend. Therefore, the React app shows
a "Welcome new user, wait while we're setting up your account".
Then
the React app makes a mutation to a signup Hasura action you'll
prepare. Once that returns, you proceed as usually (redirect the user to their home page).
use hasura action handler instead. Inside your handler, do a check if the user already exists or not. If not then insert a new row.

how to make singups and signins with different group of users

I am developing an app for my college and there are different types of users called students ,teachers , hod's
etc. When they login, how do I know a teacher logged in, or a student logged in? Is there any function in firestore for role based signups and signins?
I was thinking that when a teacher signs up, I will add a tag end of her uid.username that if username is 'DANIEL' while signup, I will add a tea for teachers and stu for students at the end of the name what they provided.
So when they login i will get the uid and do the string manupulations and get the last three letters so that i can know who logged in so that i can show different UI to Different types of users
Is there any best way to do like this ?
while singning up user enters his username example:"daniel"
i will update that username in uid.username like this "daniel-stu"(if student signed up),"daniel-tea" if techer signsup.
Storing this information in the user's display name can work. You can read it back from there next time, and take action in your application's client-side code. But note that this means that any user can change their role, since they can also call the same code to update their profile. If that is not a concern for your app, then this approach sounds like it would work.
If malicious users should not be able to change their role, then you shouldn't set that role from the client-side application code. In that case, you can set the role from a server (or your development machine, or Cloud Functions) using the Admin SDK. Since the Admin SDK runs in a trusted environment, it has expanded privileges and can update the profile of any user. So the Admin SDK could update the display name of the user in the same way you have in mind.
But this still isn't secure, since you're still setting a property that anyone can modify for their own profile. Again... if that is no problem for your app that is fine, but if the use-case requires that you can rely on the property to be correct, we have to keep looking elsewhere.
The Admin SDK can set additional so-called claims on a user profile that client-side code can't modify. Such claims are for things that affect the permissions of the user, such if the user is an admin, or what role/group your users belong to. This sounds quite close to what you are describing, so can also be used. And this time, only your code that runs in a trusted environment will be able to do so.
Finally, you could store the additional information about a user in the database. It's quite common to have a collection (Users or Profiles) in the database, where you store a document for each user (with the document name being User.uid). You create the document when the user first signs in, and update whenever you need to. You can do this from the client-side code (if there is no need to control what gets written), or from code that runs in a trusted environment (such as your development machine, a server you control, or Cloud Functions) if you do need to keep control. A big advantage of this approach is that all users can potentially see the information in this collection, where the client-side Authentication SDK only allows a user to read their own user profile.
For more on this, see:
Adding new data to firebase users (in which I essentially list the same options with fewer words)
Add extra User Information with firebase (store the information in the realtime database)
Associate Firebase Users to Database Records (also using the realtime database for the additional information)
Cloud Firestore saving additional user data
this video explaining custom claims
and many more previous questions on this topic

Password-protected page in AppMaker

I'm trying to password protect a page that contains confidential information.
Upon clicking a link, user will be shown a pop-up dialog to enter password.
If successful, redirect user to page. Otherwise, display "Wrong password".
The thing is, this can be easily overcome if user just copies the URL and add "/exec#ConfidentialPage" to the end of the URL.
Any suggestions?
If at all possible I would highly discourage implementing your own authentication system and instead rely on Google login to secure your data. See https://developers.google.com/appmaker/security/secure-your-app. My short recommendation is to:
Create a google group which contains the users you want to access the
data.
Create a role in App Maker which contains that group
Restrict access to both your data and your view to members of that role.
This is much more secure than a password based approach as #1 It's implemented by Google (implementing your own auth correctly is hard) and #2 You have a list of everyone who has access to your data in the form of the Google group.

ASP.NET MVC 2 using Authentication

Here is my problem if i can call it that way.I have implemented authentification with custom memebership provider in asp.net mvc 2.0.Everything works well but i have one problem.When user log in he provides its username and password and i check this through databse in MSSQL then i validate user and pass and use FormsAuthentication to set only UserName as profile information.
But when that user wants to create new item(lets say for sale or something) that belongs only to him and can be listed with other items that user created i can use this username(in FormsAuthentication) check it in database and connect that item to appropriate user with foreign key but that works if username is unique so i need additional informations like ID column from database table "user" to store and use it later so what is the most secure and "best practice" way to store additional information of user and use it later because username as i mentioned must be unique in database and it is not enough information about logged user.
Couldn't you store the User object (or whatever additional info you have) in the Session? or using a cookie at the client side (if you need to persist the login state even after the user closes his browser etc)? Let me know if you need specific examples.
EDIT: After reading your comments, if you are looking for a "secure cookie" solution have a look at this: http://www.codeproject.com/Articles/13665/HttpSecureCookie-A-Way-to-Encrypt-Cookies-with-ASP
I use it to store the user's id (only his id). When I retrieve this cookie I load the user given his id. Some in-memory caching allows me to avoid loading the user on each request.
But just wanted to clarify that the session object seems great for what you are trying to do + you dont have to worry about security (for the average app that is).

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