Implementing Permission Based Authorization - entity-framework

I'm implementing permission-based authorization in my ASP.NET Core MVC project. I realized how it works with entities, for example, how to give access to different users to edit, delete or update products.
But what if every product has its own creator - admin and this admin can manage roles and permissions only for his product and can't access other's products. How can I check change these permissions to consider product's id?
I leave the source which I used to learn about permission-based authorization: https://codewithmukesh.com/blog/permission-based-authorization-in-aspnet-core/

Related

With SSO (like for example Keycloak), how does one handle/synchronise users in own databases?

Consider the following scenario: you have a SSO service (let's say Keycloak), and X applications, that have their own databases, where somewhere in each database, you're referencing a user_id. How to handle this? How to satisfy the foreign constrain problem? Should one synchronise Keycloak, and the applications? How? What are some best practices? What are some experiences?
I've been using Keycloak for several years, and in my experience there are several scenarios regarding synchronizing user data between Keycloak
and your application's database :
Your application is the owner of the user data.
Keycloak is only used for authentication/authorization purposes. In this scenario, your application creates/updates a keycloak user using the admin rest API when needed.
Keycloak is the owner of the user data and you don't need more info than the userid in your database.
In this scenario everything regarding users could be managed by Keycloak (registration, user account parameters, even resource sharing using the authorization services).
Users would be referenced by userid in the database when needed.
NB: You can easily add custom data to the user in Keycloak using the user attributes but one interesting possibility is to extend the user model directly using this : https://www.keycloak.org/docs/latest/server_development/index.html#_extensions_jpa
Keycloak is the owner of the user data and you need more than just the user id (email, firstname, etc)
If performance is not an issue, you could retrieve user info via the Admin Rest API when needed.
If performance is an issue you'll need a copy of Keycloak's user data in your app's database, and you would want that copy to be updated on every user changes.
To do that you could implement callbacks in keycloak (using SPIs: https://www.keycloak.org/docs/latest/server_development/index.html#_events), that will notify your application when an user is created/updated.
NB : You could also use a Change Data Capture tools (like Debezium: https://debezium.io/) to synchronize Keycloak's database with yours.
There's pros and cons to each scenario, you'll have to choose the one which better suits your needs :)

Role Activity & Access Level

I have developed a web application with following architecture:
Frontend : Angular 6
Backend : Java REST APIs with Springboot
I want to add authentication and authorization to it. For that I'm looking for some open source application (e.g. KeyCloak, Gluu etc.). I would like to know in which tool the below scenarios are supported.
There will be predefined set of Activities on UI (e.g. Add, Edit,
Delete etc)
There will be predefined Access Levels (e.g. Read, Write, No Access)
I should be able to create Roles, then assign activities and access levels to those roles and assign those roles to user.
Can you please help me to find out a tool which supports my above scenario?
I tried something for KeyCloak, but i couldn't find a way to add activities, access levels and map roles to it. I think everything there is governed by Role only.
I just realized that I need Activity based authorization and not Role based authorization. Please help me find some tool for that.
I'm not sure what is meant by activity based authorization but i suspect you actually mean permission based authorization, in example: Grant permissions to users to perform certain actions.
Shiro offers you permissions and role based authorization out of the box.
You can create roles, add permissions to these roles and assign them to a user. Supported are implicit and explicit roles, whereas one role can hold any number of permissions. You can even work with wildcards and group the permissions.
For more information you should take a look at the official Shiro entry and especially the web documentation for your project in particular. Shiro offers full support for Spring-Boot applications, you can find a HowTo here.
Shiro fully supports your described scenario.

Allowing a user to update their own profile using the REST API

I have been experimenting with the REST API using my logged in user account's token to then make PUT requests on my user record to update some custom attributes.
In order to get to this work I had to grant my user account the manage-users role in Keycloak, prior to this I was getting forbidden responses back.
I can now make the PUT request successfully, and after logging out and logging back in I can see the updated attributes I set in my PUT request.
But I have now allowed my user to be able to manage all users in my realm, which I dont want to allow.
Instead I only want to be able to update my own account details.
I know the user can view their own profile and make changes on the Keycloak provided screens. But for certain custom attributes I want to be able to do this from the client side application they are logged in to, so using the REST API but not granting them a role that could allow them to update other users details.
Is this possible?
According to the User section Keycloak's Admin REST API, this is not possible.
One solution would be for your client app to send the update request to a backend. The backend will verify that the update request is legit (aka the JWT is verified and the update does apply to the user requesting the change).
Another solution would be to theme the User Account Service's screens to add input fields for your custom attributes, as the documentation says that:
This screen can be extended to allow the user to manage additional attributes. See the Server Developer Guide for more details.
The second option seems the more secure. I hope that helps.
This seems to be possible with the Account Management API.
Unfortunately, I didn't find any official documentation about that. However, there's an example in Keycloak that demonstrates how to do it.

Should I have multiple views/endpoints of a resource in a RESTful service?

Let's say I'm creating a RESTful service to handle orders for my warehouse over the web.
I want to allow customers to create accounts
I want a customer admin to be able to create accounts for other users in their office
I want to allow customer users to create orders
I want a site administrator to be able to create and manage all customer accounts
I want a site administrator to be able to create and manage all users
I want a site administrator to be able to create and manage all orders
Given these requirements. My initial thoughts are to design endpoints in this manner.
# to request a new customer account
/customers/request {POST}
# create and view customers - limited to admins
/customers {GET, POST}
# view customer info, update a customer
/customers/{customer_id} {GET, PATCH}
# create and view orders for a customer
/customers/{customer_id}/orders {GET, POST}
# view and update order for a customer
/customers/{customer_id}/orders/{order_id} {GET, PATCH}
I feel pretty confident that those path's make sense and follow the general restful ideas. However, I'm not sure how to handle the users endpoint. The problem is, I want customer admins to be able to create users that can use their customer account to create orders. Where do customer admins POST to to accomplish this? I had a couple of ideas.
Following this answer, I thought about this.
# creation of users always done through this endpoint no matter what the
# authenticated user's role is
/users { GET, POST }
# associate user with customer
/customers/{customer_id}/user_memberships { GET, POST }
The problem with this approach is how does the admin of the customer account get the ID of the user to associate with the customer account. Any GET request on /users would be filtered by retrieving only users who are part of their customer account. However, because the user would be created before the membership, they would never be able to view the user.
I also though about just having two endpoints to create users.
# create a user for a customer account
/customers/{customer_id}/users {GET, POST}
# root users endpoint only accessible to admins
/users {GET, POST}
# return same user
/users/1
/customers/{customer_id}/users/1
It essentially boils down to using the customer url prefix as a means of authorization. It seems a little strange to have two endpoints invalidating the other. What if the root endpoints were only views of the subresource endpoints?
# view all users in system - admin only
/users {GET}
# create & view admin users
/admin/users {GET, POST}
# create internal office users
/locations/{location_id}/users { GET, POST }
# create customer users
/customers/{customer_id}/users { GET, POST }
In this case, we could still cache GET responses on the sub resources as they would not change unless there was a POST or PATCH/DELETE on the specific id of a subresource.
This style also seems to make sense for orders. Admins can view all orders even though they technically belong to a customer.
# admin can view all orders
/orders?customer_id=1234
/orders
I kind of like the idea of the root resource being a view of subresources allowing for easier authorization based on the url.
So, I guess after all of that, my real question is:
Is having multiple endpoints representing the same resource a problem even if one of them is just an aggregate view of the subresources and does not permit the creation of a resource through that endpoint?
You shouldn't mix the design of your API, REST principles, and the need for authorization. You should design your API in a way that makes it:
easy to use
easy to maintain
easy to understand
A RESTful approach to API design tries to address these different concerns. A RESTful approach is about identifying the objects you have, their state, and their possible transition.
And that's where it stops. Now, you wonder about authorization. You want to be able to control what a user can do on given records depending on who the user is (an administrator, a customer,...) and what the targeted resource is (a customer record...).
What you need to do is deploy an authorization framework on top of your REST API in a loosely-coupled way. In other words, you want to externalize authorization. You definitely not want to build authorization straight into your API. Imagine that suddenly you have new authorization rules / constraints: you would have to recode your API. In doing so you'd break all the clients. That would lead to poor user experience.
So, we've identified you need to externalize authorization. Great. What are the different ways to do so? This depends on the language and framework you use.
You can use:
Spring Security in Java
Yii in PHP
CanCan in Ruby
... and many more
You could also implement your own filters, for instance a Servlet filter in Java in front of your REST endpoints.
Lastly, you can turn to a full-blown attribute-based authorization model based on XACML. There are several open-source and vendor alternatives. If you are not familiar with attribute-based access control or XACML, have a look at the following links:
ABAC explained by NIST
XACML
With XACML, you define policies centrally e.g:
Administrators can view all customer accounts
Administrators can modify a customer account he/she is assigned to
Customers can view and edit their own account only
The policies are then evaluated in an authorization service (in XACML that's known as a policy decision point). The authorization service exposes a binary authorization API which your API can call out to: can user Alice view record foo?.
Using externalized authorization based on policies and using XACML, you achieve a loose coupling between your business logic (your business API) and the authorization logic which you can more easily maintain and update.
According to my understanding, for ex. u want that for particular customerId you want that this customer only view its users not will be able to create its user which will only be created by admin, so this can be done using spring security as well and this definitely creates the problem so u have to categorize the customer according to your requirement.

Allowing access to an MVC site using Windows Authentication Via groups via username

I have an MVC2 site that now allows access to it via windows authentication and uses ASP.net Role provider to provide authorization. I am trying to come up with a way for the site to allow the user access to the site if his username is a member of certain groups so I won't have to sign up user in sql, but just sign up a group with access. Anybody have any idea how to do this? Is there a quick and dirty way? So far in my internet perusals I haven't found a quick and dirty way to do this? Any help would be great.
Thanks
Looking up Role/Group information for a User
ASP.NET provides a useful “Role Management” capability, which allows developers to map users into logical “Roles” that can then be used to better control end-user capabilities and authorization access. For example, as a developer I could create a role called “managers” for my web application, and then limit access to portions of the site to only those users within the “managers” role (note: I will be posting additional recipes in the future that discuss how to fully use the Role Management authorization and capabilities features more).
When using Windows Authentication, ASP.NET allows developers to create and populate roles from multiple sources. For example, a developer could setup the built-in ASP.NET 2.0 SqlRoleProvider to map Windows users to custom application roles that are store within a database. This approach is very useful for scenarios where there might be application-specific role mappings that don’t make sense to push into a centralized Active Directory tree/store.
ASP.NET also makes it easy to access central Windows and Active Directory group mappings from within an application as well. For example, if there is a Windows group on the Active Directory network called “DOMAIN\managers”, an ASP.NET application could lookup whether the current Windows authenticated user visiting the ASP.NET site belongs to this group by writing code like this:
If User.IsInRole("DOMAIN\managers") Then
Label1.Text = User.Identity.Name & " is a manager"
Else
Label1.Text = User.Identity.Name & " is not a manager"
End If
Note that the role/group look-up is done via the “User.IsInRole(rolename)” method that is a peer of the User.Identity.Name property.
src
http://weblogs.asp.net/scottgu/archive/2006/07/12/Recipe_3A00_-Enabling-Windows-Authentication-within-an-Intranet-ASP.NET-Web-application.aspx