using Thinktecture.IdentityServer3 as a Federation Provider with transforming of claims - claims-based-identity

Hello I have been trying to work out how I could configure IdentityServer3 to become a multi-tenant federation provider that can transform and enrich claims coming back from say ADSF, Google+, Microsoft Account.
Does anyone have any example code of somebody trying to do the following?
MyWebApp(multi-tenant) <-- IdSrv3 <---- ADFS
^
|<------- Google+
|<------- Microsoft Account
|<------- Facebook Account

You need to implement the IUserService - epeciall the AuthenticateExternalAsync method. There you receive the external claims and programmatically transform them.
https://identityserver.github.io/Documentation/docs/advanced/userService.html

Related

How to forward claims from external provider to requesting application

We are successfully using the openiddict support for external providers (in our pilot case Azure AD). See image for external provider claims in this example.
The external provider redirects to /Account/ExternalLoginCallback where the external provider claims are available, and the method ends with redirecting to connect/authorize (thats internally calls CreateTicket).
There we have no access longer to the external provider claims, that we simply would like to return to the calling application, e g "name" and "preferred_username".
Please guide us for this flow.
A work around could of course be to save all wanted information from claims in the database on our extended IdentityUser class and then retrieve the information later in the flow. But we want to avoid that, we see no meening to store the information we simply want to forward. Keep storage simple.

How should I implement user authentication/roles for an Electron desktop app?

I'm designing the architecture for a college project and I don't know how to deal with the user authentication and authorization part of it. The project is a desktop Electron app which would need two types (hence the roles) of users. They both need to be authenticated in order to use the app, and depending on their identity, they will have different authorizations. Since the project is meant to be used by teachers and students as part of a laboratory class after it is done, I don't think more than 30 people will be using it at the same time.
My first thought was using a PostrgeSQL database in AWS for this and implementing the authentication myself, but this means that users will have to sign up and create a new profile, which means remembering yet another <username/email, password>. Trying to avoid this, I read a bit about OAuth 2.0 and OIDC, and how it can be used to authenticate and authorize users without implementing either of those tasks oneself, but rather delegating the task to OIDC. I created a free account with Auth0 and thought about using it for the OIDC integration but after reading about 40 pages of an "OIDC integration handbook" they offer for free, I could not know if I would be able to distinguish my user base through these roles or tags as I mentioned. I just followed the steps in the tutorial handbook and tried to understand how the auth flow worked, but that didn't give me any information on my question.
So all in all what I want to know is: is it possible to implement this with Auth0 (free account) without having to use a third-party database solution (such as PostgreSQL with AWS)? If not, what would you recommend me to look into? Preferrably a solution that will let me discriminate between the two types of users BUT at the same time taking advantage of the OIDC implementation of Google for example.
There are 2 separate solutions here:
DESKTOP AUTHENTICATION
The 2 standard requirements are:
Use Authorization Code Flow (PKCE)
Login via System Browser
You listen for a login response via one of these mechanisms (I prefer the latter):
Loopback web server
Private URI scheme OS notification
My blog has some tutorials + code samples that use Electron. You can run both of the above listening options and see what you prefer.
API AUTHORIZATION WITH ROLES
You need to make roles available to the API via claims. This can be done by either of these mechanisms (I prefer the latter):
Including roles in access tokens via Auth0
Get the API to read user roles from its own database
My Authorization blog post discusses building up a claims object in an easy to extend way. The main objective is usually for API OAuth processing to result in an object something like this:
class UserPrincipal {
// The technical user id from the access token
string sub;
// The user id from your own database
string userId;
// The user's roles
string[] roles;
}
Given that object you can do things like this:
Use role based authorization when needed
Serve up user resources after login from your application data
TO SUMMARISE
Auth0 will meet some of your requirements and may be all you need in the early days. You will probably need to manage non OAuth user data in your API at some point though.
Happy to answer any follow up questions ..

Azure AD and Authorization on self Developed Applications

I have read the documentation on Microsoft.com and have only got answers about giving Applications authorization to talk to eachother but not how to implement a permission system on each different application that I have.
I basically want to know what the best practices are to implement Authorization on my .Net API and Angular Client.
I would use Azure AD to redirect external and internal users to the Microsoft Sign-In Page, I am missing a fine grained Permission system to authorise users to access different Resources on the API or on the Angular Web Application.
Wo I have to set up a DB for my API with permissions?
How do I add new users to my DB after registering them to my AD?
Im really confused here, so my questions arenĀ“t really as clear as I wish I could write them.
Compiling comments to a proper answer:
Per-user permissions are limited to appRoles, roles that you can give in Azure AD to users. You can also use security groups to achieve a similar thing if you want. But anything finer-grained has to be implemented on the app side.
For identifying users you can use one of two claims in the user Id token / access token. oid or sub. The oid is the unique immutable object id in Azure AD. The sub claim is a unique immutable id within your app. So every app gets the same oid, but a different sub for the same user. The oid claim is also used when calling e.g. MS Graph API to identify the user.

API - allow users access to only data they created

This is an API related question that applies to the APIs that I'm working on and would like to know the standard way of doing this.
say a user1 has created accounts so he can access it by
GET /accounts
but when he accesses transactions for a particular account
GET /accounts/acct1/transactions
how would this API know that the acct1 actually belongs to that user1 and is not the case where user2 is accessing user1's accounts.
This api is accessed via a Mobile app using Oauth 2.0 tokens. So while the access token control the access to API endpoints, how do we control access to only specific user's data at that endpoint. (using scopes?)
I've been looking at Spotify's apis and they seem to be doing this via v1/me end point.. Still reading...
I'm a noob at this and it looks to me that this should be documented somewhere in a standard manner in some RFC, but I couldn't find it and would appreciate direction
Can you provide more details on your use case? Why are you using OAuth?
It sounds like you need an authentication protocol - i.e. a protocol to let your server know who is accessing a particular API.
To quote the OAuth website:
OAuth 2.0 is not an authentication protocol
OAuth's main use-case is letting one application perform operations on behalf of a user of another application.
As an example, if your server wants to post a message on Facebook on behalf of a user, you will use OAuth to obtain a token from Facebook which lets you post messages on behalf of the user. Note that, in the most general case, your application does not know which user is represented by the token. Indeed, the user may not even be a (registered) user of your application - they only have to be a user of Facebook.
Practically speaking, you often can use the token you have to query Facebook for the identity of the user. So your server would extract the OAuth token from the request headers and use it to issue a query to Facebook's Graph API to obtain the user ID.
Note that the user is a Facebook user rather than a user of your app, so you will need to somehow map the Facebook user ID to your own users and permission system - i.e. check your database to ensure that the user has permissions to do what they asked to do.
This is the mechanism that is typically used when using OAuth like an authentication protocol (which, as quoted above, it is not).
I should add that if your app obtains an OAuth token and passes it to your server for the purposes of authentication, then this flow is not 100% secure, as discussed for example here, so make sure you do proper risk analysis for your case. In a nutshell, a determined attacker can theoretically impersonate your app and obtain tokens representing other users.

Recommended way to implement custom authentication provider for owin authentication

I need to authenticate users via LinkedIn, Vkontakte and other social networks that do not have providers yet.
I succeeded creating custom authentication provider in the following way:
Get code for Facebook provider in Katana source code.
Change all "Facebook" to "Vkontakte" (just find&replace).
Customize [provider_name]AuthenticatedContext class, [provider_name]AuthenticationHandler.ApplyResponseChallengeAsync() and [provider_name]AuthenticationHandler.AuthenticateCoreAsync().
Everything works well, but just wondering. Much code is duplicated with no actual change. Is there a way to use any standard stuff for building custom provider, not just copying the files?
Unfortunately not. I also created new providers for LinkedIn and Yahoo and even though I copied much of the code from the Katana project there are little nuances with each provider which means you cannot really use a single code base for all.
BTW, you can check out the LinkedIn and Yahoo providers at http://www.beabigrockstar.com/introducing-the-yahoo-linkedin-oauth-security-providers-for-owin/