Customizing Single Sign on in IdentityServer4 - identityserver4

I have multiple client and use IdentityServer4 for authentication. After I am logged into the first client the subsequent client are automatically logged in due to single Sign On. However what I want to know is, does the second client's authentication request makes any round trip to IdentityServer. If yes is there a way to intercept this call either by extending or customizing the implementation.
Any help is greatly appreciated

I assume that the clients where you want to intercept use the implicit or hybrid flow.
If so, have you tried one of the events on OpenIdConnectEvents? Say OnTokenValidated?
OpenIdConnectEvents Class

Related

identityServer4 with Login Step-up and MFA

In one of my Projects i need to implement Login Step-up. That means a user can login an application with simple username and password to get some readonly access access on website and API behind it.
If user want to performan any sensetive data operations like "write/update", he need to authenticate via second factor (via SMS code).
second factor login is for maximum 10 minutes valid, if user does not interect the website for 10 minuets, he will be automatically logout from second factor, but he still remain logged in with one factor.
can identityserver4 support this szenario out of the box? or do i need to implement it by my own ?
Here is my solution proposal:
for one factor login, identityserver provide a one factor scope, which client need to understand. it provide a access token which also have limited scope.
when client application need two factor scope, it call identityserver again where user must provide second factor authentication. hence a new token with second factor scope sent back to client. with this token client can call API methodes which need second factor authentication.
second factor authentication token has a validity of 10 minutes
after 10 min token is invalid, but one factor token is still valid as it has long life time.
Questions:
- Can IdentityServer4 offer Login Step-up out-of-box? if no, what are the alternative solutions ?
what is your suggesstion regarding my solution proposal?
Thanks in Advance
What you wrote in the bullet points is basically how I'd see it implemented in IdentityServer4. It's just setting up two different scopes and issuing two separate tokens for the same user. First scope 'readonly', lifetime=24h, acceptable only by safe operations in the application api, second scope 'full' with lifetime=10mins acceptable by all operations. No big problem, it should be perfectly doable with basic IdentityServer4. However, you will have to RT(F)M and configure the scopes, clients, tokens, etc. in the IdentityServer4 config. And also, you'll have to implement the two-token access policies in your app's backend api implementation, and of course client apps will have to be careful about which token they obtain and which token they use for which backend call.. but all of that is more-or-less obvious (and you seem to understand that, judging from that bullet points) so I don't quite see what you'd want by saying "out of the box" or what are you worried about in terms of support for that on the IdentityServer4 side..

Can the client modify react component state?

I'm building an admin page for an application and have a state value 'authenticated' that flips from 'false' to 'true' after a successful login (which is authenticated on the server) which then shows the actual admin panel.
Are component state values safe from tampering by the client? Basically, if the client can modify my 'authenticated' state value to 'true', they can skip the login and go straight to the admin panel (which I obviously don't want).
I read that React Dev Tools allows the client to modify values yet everyone says "validate on the server" but I am validating on the server and updating my state accordingly, if the user is approved. If it is not wise to have a state value manage this, what is the right way to conditionally show the admin page after a successful, server-side authenticated login?
I think this is an important question since tampering with state values in a React app can have huge negative consequences on data integrity within an app/database.
TL;DR: Either require an authentication token with every request or require authentication through a session.
Never trust users always. One potentially big issue is if you "hide" admin actions behind the admins page without requiring authentication.
For example, assume the backend server uses a REST API to accept commands. In the admin panel you get links to administrative actions like a button 'Delete Everything' that sends a DELETE request to server.net:8080/api/admin/everything without requiring any authentication. If you're a user, you can find that in the code potentially and then send a DELETE request to that address from anywhere without any repercussions.
We'd never give administrative privileges to anyone who would want to delete everything... Because we'll never untrust someone. Right?
Worse, someone might find the server and fuzz some inputs to it, and oops! They manage to delete everything (or even worse, GET everything stored in the database). This wouldn't be hard to do, especially if the server you use to authenticate is the same server you use to issue commands. History has proven "security through obscurity" to be a very bad paradigm. Every action should be authenticated, even if it seems like the actions will be hard to find.
Generally, providing a JSON web token or some other form of authentication token and having the user send that with every request is a good start at least, especially if it has an expiration date. The token would be provided through a separate request with valid credentials.
Sending a token with every single request obviously isn't ideal. There are a couple of other things to try. For servers using PHP, you can probably trust sessions (though very many people who know more than me would probably disagree). In more modern cases, you could try to use Web Sockets, requiring the token after connection. Then only after authentication with the token do you allow the user to make administrative requests.
That way, even if a user knows the exact command they can send to perform any action, the server won't let them without a current session or token. Unfortunately, unless you're already using Web Sockets or depending on a session, it will likely require a lot of changes. I'd consider this to be critical though.
It is always possible to tamper values in the front-end, there is no way you can rely solely on the front end to ensure security.
Your best approach is to implement some form of authentication and authorization on your backend. In this way, even is some users pretend to be admin, they will be blocked when you do the next request to the server.
Perhaps if you can send more information regarding your problem, we can think of a more specific solution.

Mobile App authentication for admin actions

I am developing an application where users are playing a game and upon completion their results are sent to my back end through a POST request. Since I do not want this POST request to be done manually by someone who finds this endpoint (and mess with his results), I need a way to restrict it so that it can be done only through the application. However is it safe to hardcode a token that provides this access?
What is the correct way to go around this problem ?
I would not recommend to use hard-coded tokens, if the token gets compromized, you have to change the server as well as the client.
I would recommend some sort of auth mechanism as JWT with ssl with one rudimentary username/password system.

What's the simplest way to get user Groups from WAAD?

I've got AngularJS and Web.API WAAD authentication up and running. For client side I use great library ADAL.JS. For backend I use Microsoft.Owin.Security.OAuth. This part went quite smooth.
Now I want to implement authorization based on roles (which will be mapped to WAAD groups). Groups are not included in authentication token so I must ask Azure Graph API for them. I saw various ways to do it, using custom claims providers, adding web services to project, etc. Some examples already providing mapping between groups and roles to use in [Authorize] attribute.
But what is just the simplest example of how to get a list of group ids/names from WAAD providing User ID or username, when I'm already authenticated?
Also, is there any way to get this data in JS to use in Angular frontend, or should I create an API service which Angular should call for roles info?
In the non-JS case, the simplest way of getting groups in the token is by opting in. Download your application’s manifest, locate the “groupMembershipClaims” entry, change its value to “SecurityGroup” or “All”, upload back the manifest.
However note that this won't work for your scenario, because it uses the implicit grant - here the token is returned in an URI fragment, hence a big token would risk blowing past the URL length limits of the browser.
You can always request groups to the Graph and make it available to your frontend via custom action on your API, but from what you wrote you are already familiar with that. Let me discuss the matter here - if there's a simpler route to make this work in SPAs, I'll get back to this thread.
HTH
V.
Update: I verified and in the implicit grant case you will receive groups always via the overage claim. Please refer to https://github.com/AzureADSamples/WebApp-GroupClaims-DotNet/tree/master/WebApp-GroupClaims-DotNet - it will show you how to process the overage claim to retrieve groups. All you need to do is apply the same guidance to a web API instead, and if you need to make the info available to the client expose one or more actions doing so.

Endpoints API with authentication

My question is : can I use endpoints API or a service with OAuth protocol in general, in sort of that i not need to authenticate the user all time that it send a request to the server but only the first time and for the other times I will use type of token or whatever to use the server directly without check oaut. ALl that in a secure way of course.
the process of check oaut is slowing the response.
Thanks
It depends what you mean by "authenticate the user". OAuth as implemented by Endpoints (and demonstrated with samples) suggests you authenticate the user the first time they use the application (either at install time, or each time they load the app in the browser). From then on, the identity of the user is represented by a token, managed by the client library, and sent along with each request. The server will always verify this token to determine who is making the request, but it does not require user-facing interaction.
If you're asking whether you can use OAuth without continually making the user identify themselves (via an OAuth popup, etc.), yes, this is the way it works by default in the samples.
If you're asking whether you can use OAuth without verifying the tokens on each request, you could, but it's not worth doing, because it doesn't get you a lot from a security perspective or save you much performance-wise.

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