Auth server for validate IdentityServer4 access tokens - identityserver4

We are using IdentityServer4("http://docs.identityserver.io/en/release/quickstarts/0_overview.html") to protect our APIs, actually we have multiple APIs and we want to protect these APIs with IdentityServer4(i.e via generating access tokens) but we have questions regarding validating the access tokens,Do we need to create separate auth server for validate IdentityServer4's access tokens?
Actually our APIs are already build and deployed.

Once you specify to your api, that it should use IdentityServer for authentication, and of course you specify the authority, you don't need to do anything, except registering this API in Identity Server, and put the AuthorizeAttribute where you need it in the API.

Related

When to use Azure AD to protect Azure API Management?

I am working on one API which will be exposed to a couple of external clients. And I would like to limit access to my API and let only trusted 3rd parties access my API. I have found that Azure API Management provides subscription keys, which can be used to protect API - https://learn.microsoft.com/en-us/azure/active-directory-b2c/secure-api-management?tabs=app-reg-ga
Moreover, I see that I can connect my API to Azure AD - https://learn.microsoft.com/en-us/azure/api-management/api-management-howto-protect-backend-with-aad, which might be useful if I want to restrict access based on roles and types of external systems (for example some external systems will have one role that allows using some additional features)
Could you please help me to understand all other cases when I must use Azure AD instead of subscription keys? And can I use them together?
I also would like to understand which approach is the best for me if you want to give access to the client apps (browser, mobile apps and etc.). As I understand, Azure AD B2C can be the best option here
For your requirement, if APIM is not necessary (you do not need to configure the exposed url of your api by APIM), I suggest you to just use Azure AD to protect your api. You can refer to this document.
If APIM is necessary, and your requirements do not need to limit multiple permissions for different role to access the api (in other words, you just want client can/can't access the api). You can implement it just by subscription key as you mentioned in your question.
If APIM is necessary, and your requirements need to provide different permissions for different roles to access the api, you can do it as the second document link you provided. You can validate the roles or other claims of access token to provide different permissions to client.

PowerBI Accessing a secured rest api

I need help, I am new to PowerBI but I am know few stuff in Azure and C#. Anyways here is my current scenario: I am trying to get data from a REST API and show it as a report in my POWERBI unfortunately my REST API is AAD Protected so I need to provide an Access Code every time I tried to access my API. If you could point me out what should?
I usually use implicit flow to authenticate my user and for them to use my REST API but in this case is Implicit Flow still a possible solution? If not is storing Client ID and Secret safe to be store in PowerBI?
You can also use implicit flow with MSAL 1.X which is old version but it is not a recommended for the purpose of your apps security.
You need to handle the access code to automatically pass to the server and get the access token when using Auth code flow.
Technically For your scenario, you can also use client credentials flow which will not require a user credential involvement and there is no need to pass access code which is only part of auth code flow.

Why do I need two AAD applications just to add roles into an access token?

As shown by many samples I have two AAD application registrations, one for my javascript-based front end, and one for my JSON-only web APIs.
If I fully trust my client AAD application, why does AAD require me to create a second AAD application for my web APIs?
For example, assuming I add specific roles to my client AAD application, if client signs in with AAD and gets an id token and access token containing my roles, it only needs to send the access token to my APIs. The API only needs to crack the JWT, validate the audience, issuer, tenant, roles permissions, and signature. In this world, no client secret is needed in the web APIs, a second AAD application registration not needed, and still no call to AAD from my APIs. Unfortunately, without two AAD applications, I cannot figure out a way to have AAD include roles into my access token.
If I didn't fully trust the issuer from mucking with claims, I can see why I would need two AAD applications and a client secret. But since I do trust my AAD application and the signature of the JWT, why the extra complexity? Or maybe there is a way to do this that I haven't found?
Thanks!
Responding to Marc here because just not enough characters in the comments field -- The sample you referenced is an excellent sample, specifically the JavaScript one calling the Web API. It is what I am doing right now in fact. However, the problem is that Web API in the sample is open to anybody who has authenticated on the tenant. I need to secure the Web API down to certain individuals in the tenant, and simply checking the client/app id is not sufficient as anybody who can create an AAD app can fake it.
So what I need to do is have roles added to the the access token so I know that my application authenticated the user, and that user has been granted the required roles. For example, here is a Microsoft sample. And even here a Microsoft video walking through the process.
If I don't have two AAD applications w/client secret, the roles claims is never provided in the access token. It is always provided in the id token, but not the access token.
I feel like I am missing something obvious here. If AAD would just put the roles I requested into the JWT when I authenticated against it, and I validated its signature, audience, issuer, and roles, I wouldn't need any of this extra complexity?
Ah, I think I understand where you are going: you would like to control which users can access an API, no matter what client app they are using to access the API with. That's a function of the API - you cannot control that through AAD. In AAD you can control which users can access which applications (UI) using either user access restrictions (enterprise tab) or role-based access. However, access to an API is controlled in AAD at the calling application level via scopes. APIs are never accessed directly by users but only by other apps so controlling access permissions at user level would cause admin havoc. So, you can control what permissions a user has in the app they are using and you can control what permissions that application (client) has in other applications (APIs, resource servers) it is using.
In other words: role is about user access to UI, scope is about one apps' access to another.
App secrets provide added security for getting tokens - they have no bearing on what permissions are included in the token.
Can you provide a link showing that two apps are needed? That should only be the case if the API you want to call is not provided by the web app which served the JS to the browser. None of the 'official' samples require you to register two apps (Graph API, used in some of these samples is a separate API and it is already registered). A problem with tokens passed from the browser is that they were acquired by a public client, not using any secrets apart from user creds. Therefore, they are easier to steal and re-use. Your own back-end app may want to use a secret to get its own token (extension grant) to call yet another API using a token that does not reside in a public client.

Allow OIDC Users to use clientCredentials to gain programmatic access to trusted APIs

What is the correct way to provide users with programmatic access to APIs?
I have an application composed of many services (all trusted services, within the same domain, not external applications), and identity service in the same domain.
I would like to allow a user to user a set of credentials to gain access to any of the APIs I provide.
Is it reasonable to think of a user as a client in this case, and use clientCredentials flow to get a token that will be passed to the target API? specifically, is it a good idea automatically assign a clientId and a clientSecret to every user in my system, and allow all users to use clientCredentials flow to request an access token? the access token would then contain all user's claims. If this is a reasonable approach, is there any way to remove the "client_" prefix from the added claims? or is that a bad idea?
This was originally asked here: https://github.com/IdentityServer/IdentityServer4/issues/1877

Can I just create and store list of auth tokens instead of using JWT and similar?

I'm creating my first SPA using NodeJS stack for development and I came to a point where I should design authentication and secure some parts of the app.
I read a lot about auth techniques including JWT, OAuth, etc. but I still didn't find something like «a real world example».
Let's assume that my task is just to secure some parts of app from public. My app isn't designed to work with 3rd party services so I see no need to use something like Google or Facebook auth. I want to use login/password and store all this data using my own database server.
I don't understand the point of having authentication stateless. I came to a simple conclusion that I can design authentication in this way:
I store users logins and passwords in my database.
User auth means that user enters his credentials, server checks it and creates token. Then server saves this token into database. User saves token using browser local storage or somewhere else if it's not browser environment.
On each request client sends this token, server checks that this token exists and responds appropriately.
User can login from different devices, we just create multiple tokens for him.
We can end specific session or all sessions by just deleting user tokens from database.
We can manage tokens in a way we want, for example server can check expiration time and invalidate (delete) token.
Is it OK? JWT require additional implementation if we need to invalidate token, I saw different examples, all of them were based on storing invalid tokens but what's the point of that if we can just store valid tokens? We already lose statelessness by implementing this storage.
I see that I can just use cookies instead of implementation described above but I don't like an idea to use cookies in RESTful app because it really depends on browser-like client environment.
What are the disadvantages of just storing tokens on server?
I have implemented one project in which user authentication is required and token is stored into database.
You can find that example here.
You are describing the traditional authentication approach using session cookies. The server stores a session for each connected user identified by a sessionid. The sessionid is stored by client in a cookie and sent in each following request to identify user.
You can use this method perfectly, both in browsers or mobile devices (using the device storage instead of a cookie)
The drawback is that it requires many server resources to keep sessions open and requires database queries at each authentication to retrieve user data. This is what JWT solves. The user information goes in the token itself, and is reliable because it is signed with the secret key of the server.
JWT has its own drawbacks, for example it is not useful if you need to have a revocation list, because them will require server storage.

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