Multiple OAUTH providers in .NET app how to handle identical querystring? - c#

I am creating a .NET app and on one of my screens I have different services to hook up to using OAUTH.
An example of two are Facebook and Instagram. I allow the user to authorize my app access to these applications. Everything is working fine individually however I cannot figure out a good way to know which provider the user selected(I have a simple button click for each service) on callback since both Facebook and Instagram both return "code" on the querystring. Which is then used to do the final step of the OAUTH authorization.
I tried storing the button clicks of each service in session however my session is getting wiped on the redirect to the providers authorization URL and on the return to my app on the callback (and yes even with Redirect(url, false) my session is still getting cleared). So basically I have no clue what button the user clicked with the service the authorization is coming back from (Facebook or Instagram).
Any thought or ideas to know after a user authenticates my app and the callback is made how to know what provider sent me that callback in code behind?

Can't you have them go to different callback URLs? Is there a reason why they need to go to the same URL?

You could include this info in the OAuth 2.0 Authorization Request's state parameter (which you should already use to prevent CSRF attacks), e.g. by appending a _fb or _ig to it.
However, the more convenient way would be to have different callbacks.

Related

Silent token retrieval in Identity Server 4

Is there a way for a native/WPF application to get Identity Server 4 to issue a token without the need for a user interface in the way that Microsoft's MSAL library allows you to - https://github.com/AzureAD/microsoft-authentication-library-for-dotnet/wiki/Integrated-Windows-Authentication.
The MSAL library only works where you have a Windows user that is backed up in the Azure AD tenant specified by the authority property.
Using the .NET HttpClient class, I was hoping that if I set the UseDefaultCredentials in the HttpClientHandler and setup Identity Server so it uses Windows Authentication as its "provider" that this would be possible.
However when trying it I get a 401 Unauthorized when it tries to authenticate the user at this point in the Quick Start example. I suspect I'm getting Windows Auth problems with the HttpClient class even before we get into Identity Server specifics.
If I got past this stage I would also need to be able to handle the callback to deal with the code/access token. Is there another way to do this?
I realise that a browser window can be shown in WPF to handle everything but for complicated and political reasons within the company we would like to avoid this if possible.
So the proper way to do this is use Auth Code with PKCE, you can configure this to give you a refresh token, so you can argue that you only see the browser once when initially logging in. (I advise this)
If you can't get a refresh token, you can do silent refreshes with headless browser.
If you don't want the browser window you can again have a headless browser and just interact with it via the UI, and simulate the flow without anyone seeing it. (I do not advise this)
If you don't want the browser at all, you can use Resource Owner Password Credentials flow. Please refer to Scott Brady's blog post about weather you should or shouldn't use it.
Many members of the OAuth Working Group now consider the ROPC grant type as deprecated.
And as for
I realise that a browser window can be shown in WPF to handle everything but for complicated and political reasons within the company we would like to avoid this if possible.
Tell them it's impossible to avoid this.

Authentication for local application using website

I am creating a .NET class library which will allow local applications to access the accounts of users registered on my website, using an API. I would like the library to handle all authentication of users, so that any app I create an simply call the library, and be returned a token for the API. I'm not sure how to do this authentication.
There are a couple of ways I have considered doing this, however they are not ideal. The first would be to simply create a login form within the library which asks users to enter their login then calls the API. The second method would be to have a webpage where the user logs in and is then given the token which they enter into the app.
The ideal scenario for this situation is that the user does not see their token, and the actual login process is delegated to the website if possible. Both of the above ways lose out on one of those conditions.
The ideal way I would like to do this is inspired from an app I use where if the user is not logged in, they must press a 'Sign In' button, which opens a webpage where they log in. Once they have done so successfully the app automatically detects this and they are signed into the app. The downfall of this solution is that I have no idea how I might do that myself.
Essentially what I'm asking is, is the third solution viable, and how could I do it, or if not are there any better solutions I've overlooked.
FYI the website and API run ASP.NET MVC and WebAPI respectively and the library will use .NET framework.
Edit:
From the comment below it seems likely that you'll want to implement an authentication provider using something like OAuth. The .NET reference libraries can be found here and there's a similar answer already on StackOverflow that may also shed some light.
Welcome to Stack Overflow!
Personally, I would keep the Web API as the authority on authenticating a user and just consume this HTTP endpoint on all platforms (web, desktop, mobile etc) whenever you want to validate a user's credentials.
At a high level the process would be along the lines of:
Have your "clients" (desktop, mobile, web applications) submit HTTP requests to an API route (something like /authenticate) when the user first logs in.
Run your authentication logic
If successful return a token (and cache this this for use in subsequent requests)
Otherwise return a 401 response
Every client will now get a standardised response they can use for determining if they should redirect the user to some protected area, or show them an error message.
This also allows you to design login screens that are native to the platform they're running on (which is a smoother user experience). I wouldn't recommend having a library return a pre-built login page to the user - you'll find that becomes a real pain to maintain!
The third solution you proposed is also a valid way of doing things - but it does have the side effect of redirecting the user's focus away from the application they're using - which you may not want depending on your use case. It's also a bit trickier to implement than just calling the API directly, so unless you have a specific requirement to do it this way I'd not recommend it.
Hopefully this makes some sense. If you are unsure on how to implement cross application authentication then I'd recommend taking a look at some existing answers on Stack Overflow such as:
Basic token checking
OAuth

Handling security in an ASP MVC application that uses JS to a REST API

I have an ASP MVC4 web site. Originally, most of the content was served via controllers as one would expect. I have moved the data storage from SQL Server to MongoDB. I have also added a lot of ajax to update data client side, without a full refresh. This is working fine, but my controllers now have lots of methods that take json and return json. I was able to build a Node.js server that hits the database and exposes exactly the same functionality, without lots of going to and from C#.
My javascript client-side is now calling a Node.js REST API, this works great. My 'secure' code (like adding a new user) hits the same REST API from the server side.
My question is this: How can I handle security properly with this? I have three scenarios:
GET api/messages: No need for security, I want to expose my site's messages to anyone who is interested via a Json REST API.
GET api/my/messages: I need to allow access to this only if the user is logged in (it gets the user's messages).
POST api/users: This is a function that should only be called from the server, and nothing else should be able to use it.
As the user is already logging in to my ASP website, how can I use their logged in credentials to authenticate them with my REST service? While the user is logged in, the pages client side will hit it regularly for updates.
Is there any sensible/standard way to do this? The core idea is that the client side code uses a REST API that is at least partially open to the public, and that in fact that API offers all of my business logic - only parts of it (like creating a user) are locked down to super-admins only.
Thanks in advance!
Create two authentication middleware handlers. One you add to all your "my" routes and another which you add to your POST routes.
The "my" authenticator takes the asp.net auth cookie that is present in the request and makes a http call to your asp.net mvc site with it.
You'll need an action which either returns a 401 if the cookie is invalid otherwise it returns some info about that user's permissions perhaps.
If the request into node doesn't have a cookie, return a 401 again.
In addition, to prevent excessive calls to your mvc site to check the cookie, you could use the cookiesession middleware to set a cookie on the client with a flag of authenticated. That will result in 2 cookies for your client, but that shouldn't be an issue. Just make the node one expire before the aspx one.
The POST authenticator middleware can use any shared secret you like between your node and mvc server. e.g. a special header in the request.
If the user is required to login you can use [Authorize] on your controller actions. Autorization will be handled like any other webrequest.
Furthermore you might consider to add a key to your api requests which you can provide in the initial page load. A autorized user will have a GUID which he will sent with the api call. You can check if this key was issued by your app to a valid user.
As you said all the secure calls already go through your MVC server code which in turn calls the Node.js code, am I right? Basically you need a way to block calls to this Node.js from other clients that are not your MVC code.
Thinking out loud, these are the ideas that pop into my mind:
Use SSL only between MVC and Node. You can set up client and server certificates so that the Node code will only respond after authentication (I don't know how Node handles SSL so you will need some documentation here
If you want, the Node server could also check the call origin and so you can filter based on IP and only allow IPs where your MVC code is sitting
Use an encrypted authentication token on the secure methods on the Node code. Again I'm not really a Node expert but I can imagine it has ways of decrypting a token, or you can simply base it on a random number with a common seed... If noone has access to your server code ideally noone should be able to guess this token. Again, SSL will help against traffic sniffing
I am quite sure that people will come up with other ideas. For me, the most basic thing is anyway ensure that the secure methods are only accessible through an SSL connection and on this connection you can exchange all the info (token, passwords, etc.) you desire.

Authentication & Authorization with WPF Client to MVC 4 Web Api

I have created a MVC 4 Web Api using Entity Framework Code-First and a WPF-Application as a client in VS 2012.
The problem I'm struggling with at the moment is that I have to enable Authentication from the client and authorize users for access to the Api (for example: Every authenticated user can access GET methods but only admins can use POST or DELETE). I used MVC 4 Internet Application because of Forms Authentication already being included, which worked fine until I tried to login from my client application. After spending some time researching my problem about I realised that Forms Authentication is mainly supposed to work with webbrowsers. I even found some possible solutions to get it working with HttpClient using CookieContainers (e.g.: How do I set a cookie on HttpClient's HttpRequestMessage), but nothing works for me.
After spending some hours researching ways to accomplish what I'm trying to do I feel completly stuck..
I've read about SimpleMembershipprovider, BasicAuthentication, OAuth and someone mentioned Thinktecture.Identitymodel, but wasn't really able to decide which would work best.
If there is really no way to use Forms Authentication when connecting with a client other than a webbrowser then what is the best Authentication/Authorization method to take?
I would be very happy if anyone could provide me with a hint on what works best in this case, because after researching for hours I only get more and more confused.
Thanks in advance for any help!
You should be able to do this easily enough, but you haven't said what your problem actually is. Are you
unable to get access to your web api actions because you aren't logged in; or
unable to make it enforce authorisation (i.e. you can get anonymous access to actions)
For the second scenario:
There is a very good overview of using Authentication and Authorization in ASP.NET Web API on the server side, and the various ways you can enforce different roles on Actions.
There is also another approach that is appropriate for machine-to-machine (i.e. where you don't have a user who will type their login details into an appliation dialog box) in Making your ASP.NET Web API’s secure, but it doesn't focus on using SimpleMembershipProvider. Instead of using the framework auth&auth components it uses tokens (take care with this approach - rolling your own security is very very hard to get right).
For the first scenario:
From the client side, it sounds like you have some a C# application that user's interact with. If this is the case (rather than the machine-to-machine scenario) then your Forms-based approach is still suitable, and you are doing the right thing with your cookies. The approach would be:
Ask the client to type their username and password in to your application
Send a request to your LogIn action on your AccountsController, this will return your authentication cookie, session cookie etc.
Store the cookies that are returned from this (successful) login (or notify the client if the response was "login failed"
Then use those cookies in the request to the web api
As you are already talking about using HttpClient, I'm guessing you know what you are doing for this, so haven't provided code samples. I wouldn't use HttpClient, for what it's worth, but HttpWebRequest which allows you to keep a common CookieContainer through the HttpWebRequest.CookieContainer property.

How do I create a .NET Web Service that Posts items to a users Facebook Wall?

I'm currently toying around with the Clarity .NET Facebook API but am finding certain situations with authentication to be kind of limiting. I keep going through the tutorials but always end up hitting a brick wall with what I want to do. Perhaps I just cannot do it?
I want to make a Web Service that takes in the require credentials (APIKey, SecretKey, UsersId (or Session Key?) and whatever else I would need), and then do various tasks: Post to users wall, add events etc.
The problem I am having is this: The current documentation, examples and support provide a way to do this within the context of a Web site. Within this context, the required "connect" popup can be initiated and allow the user to authenticate and and connect the application. From that point on the Web can go on with its business to do what it needs to do.
If I close the browser and come back to the page, I have to push the connect button again. Except this time, since I was already logged into facebook, I don't have to go through the whole connection process.
But still ... How do applications like Tweetdeck get around this? They seemingly have you connect once, when you install their application, and you don't have to do it again. I would assume that this same idea would have to applied towards making a web service because: You don't know what context the user is in when making the Web service call. The web service methods being called could be coming from a Windows Form app, or code behind in a workflow.
I would advise you to try Steve's blog and starter kit
you can also find a reference to his post in this so question
Good luck
Edited/Added below
You cannot store the facebook login credentials for users and pass them to FB.
(terms & conditions)
but you can use: offline_access, to access some usage without flagging the user as logged in.
Cool tip from this forum:
Use the following URL with your API Key
http://www.facebook.com/login.php?api_key=YOURAPIKEY&connect_display=popup&v=1.0&next=http://www.facebook.com/connect/login_success.html&cancel_url=http://www.facebook.com/connect/login_failure.html&fbconnect=true&return_session=true&req_perms=offline_access
Register for the Facebook Developer
App on your facebook profile.
Create a new app Web App(By default)
through your "Facebook Developer
App". Change the Application Type to
"Desktop App". Note down the API Key
& Secret Key for you app.
Authorize the app & authenticate the user and
then get the permanent session_key.
Authentication
For a fully logged in session, you are asked to use (again terms and conditions) login.php and you can login via JavaScript
HTH
Ric

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