WCF custom auth using session id - c#

I need to create a custom authentication/authorization on an existing WCF service, which should be per-method: some methods should force user to log in, and other should allow anonymous usage. The service is implemented as singleton.
To do so, I want to do the following:
enable sessions with default behaviour, so each of the existing service methods will be initiating session in case it doesn't exist;
add login(userName, password) method, which will keep a successful login artefact in a wrapper around Dictionary<>, with current session id used as a key;
add logout() method which closes the session and removes the artefact from the dictionary;
add sessions monitor which will use Dictionary<SessionId, WeakReference<OperationContext.Current>> to drop sessions, for which the logout() method was not called. The monitor will be executed each time a new session is added.
There are two questions though:
Is there a simpler method to achieve per-method auth?
Are there any problems with this approach?

I haved a similar problem a few days ago and I found a solution.
You can check if you want;
WCF service and adding custom Identity claims

For custom authorization you should use Custom Authorization Manager. You should manage sessions with ASP.net which you can have access if you enable AspNet Compatibility.

Related

Asp.Net Core 2.2 - Understanding Authentication Middleware and External Logins

I have been trying to wrap my head around this concept but have many questions and unfortunately, all official documents and tutorials are based on Visual Studio templates with individual user accounts.
My goal is pretty straightforward I believe. I have a web application which will only support external provider logins (namely: Facebook, Twitter, and LinkedIn). I do not want to support cookie authentication since there won't be a support for custom username/password.
My first problem is to define a default AuthenticationScheme. Below is my startup.cs:
services.AddAuthentication()
.AddFacebook(/* options */)
.AddTwitter(/* options */)
If I define a controller action with Authorize attribute I get no default authentication scheme defined error when I hit that route. However, I want users to be redirected to my login route if they are unauthorized. If I modify startup.cs like below it all works but then I think I support cookie (old forms authentication?) authentication which I don't want to.
services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
.AddCookie()
.AddFacebook(/* options */)
My other issue is that I don't know what happens under the hood of AddFacebook() call. If I set up my middleware this way and log in with Facebook I magically get all the necessary tokens, claims and suddenly I have an application cookie set and my fb_login callback route can access to Facebook's token! When I check the network requests I see there is a hit to the signin-facebook route -which I didn't define- and I guess under the hood it calls HttpContext.SignInAsync() etc... but if I refresh my fb-login callback and check if
HttpContext.AuthenticateAsync(FacebookDefaults.AuthenticationScheme)
returns Success = true no! it returns false! But it was true just one second ago?
Also, when should I be using methods like AuthenticateAsync() and SignInAsync()?
Long story short I need a tutorial or documentation that explains this middleware without asp.net Identity framework, EntityFramework and templates.
I want to understand how a simple AddFacebook() call binds everything, and if I want to manually do that (say with AddOauth) how can I achieve the same functionality?
I'm not a fan of "automagically working" code so if someone can explain what's going on here I'd be very appreciated.
Cookie auth is used to persist the authenticated state between the requests. There is no substitute for this, and no it's not the same as forms auth, though cookies are used in both cases. The reason for that is simply that cookies are what makes state work over the HTTP protocol, which is itself stateless. If exclude the use of cookies, then there is no other mechanism to maintain state.
Using something like the Facebook auth scheme directly authorizes the initial request, but again, because there is no state, the next request is no longer authenticated without going through the Facebook OAuth flow again.
Long and short, the other auth schemes are there for things like APIs, where each request is typically authenticated individually via something like the Authorization header. A web browser doesn't work this way, and instead relies on cookies handle subsequent authorization. No cookies, no auth.

Multiple "Forms Authentication" like cookies per application

I am planing to implement a mult- tenant MVC application, where each tenant gets a "sub site" URL, so that rooting would look like:
www.mysite.com/{TenantId}/{Controller}/{Action}
When a user logs into the application, the login shall always be associated with a single tenant (there is no need for single sign on). However, it should be possible that he registers with two or more tenants in the same application. In such case, I need him to be able to simultaneously use both "sub sites".
As I understand it, the FormsAuthentication is using one cookie with a name specified in the web.config, visible in the code through FormsAuthentication.FormsCookieName.
I was thinking about imlementing an approach similar to this one: implement custom cookie creation and checking (using FormsAuthentication.Encrypt\Decrypt for creating the tickets and then manually creating cookies with different names for different tenants). In this way the user could have several cookies, one for each tenant "subsite".
I am wondering, if this approach seems sensible/secure? I was dotPeeking the FormsAuthentication stuff and there is quite some additional stuff under the hood - with a reason I suppose. Also reading articles like this (where the cookie expiration in the secure connection scenario was not handeled properly) makes one wonder, if custom security implementation is really the best way to go...
Alternative to several cookies might also be setting the cookie Path property. If I understand it correctly, the cookie shall be sent only with requests starting with {TenantId} if I set its path when creating it? Will FormsAuthentication know how to handle such cookies? When new ticket will be reissued, will the Path be respected?
And of course, all other suggestions are appreciated as well.

Custom httpHeader or soap header into claims-based authorization by endpoint/contract

I have a ServiceHost that implements many Contacts on various endpoints and bindings ((http & https) x (rest & soap) with Anonymous Access, Windows, or Custom authentication, as bound depending on the Contract) & nettcp with Windows authentication. Custom authentication is embedded in the http or soap headers. Each endpoint and contract has its purpose. It should all be manageable on a single ServiceHost - I don't want to split it up.
I've gotten it to the point where all the endpoints work and serve their content correctly, but the authentication/authorization isn't integrated into the WCF stack. I have been using a MessageInspector to handle validation of the authentication header and allowing it if the token was valid.
Now I want to integrate the authentication/authorization into the WCF stack. I want to be able to access the identity and check the claims in each Operation's implementation. And perhaps basic claims can be authorized centrally, like "are these claims authorizing anything at all in this contract?" (by contract type).
In the case of custom authentication, I have a signed/secure token that includes a custom implementation of identity and property claims which I can properly extract and convert into WCF claims upon receipt (even if I don't know exactly where to put them once I've got them). For Windows authentication, I just need access to the default Windows identity stuff.
I can set the ServiceAuthenticationManager and ServiceAuthorizationManager each to custom values, but it's not doing anything I want it to and I'm getting totally lost.
For example, the ReadOnlyCollection<IAuthorizationPolicy> authPolicy coming into Authenticate() seems to be inconsistent - sometimes it's empty, sometimes it has one UnconditionalPolicy and sometimes it has 2 or more (4?) of my custom IAuthorizationPolicy already there. Meanwhile IAuthorizationPolicy.Evaluate() gets executed anywhere from 0 to ~9 times per request. Sometimes, within IAuthorizationPolicy.Evaluate(), OperationContext.Current is null! And sometimes the evaluationContext.ClaimSets already has my claimset. Yet state is always null even when I give it a value in a previous enactment.
Rather than tackling these problems individually, I think it'd be better to step back and ask for some high-level explanation of what I should do/expect to see.
Authentication: When a request comes into the ServiceHost, it needs to get Authenticated. At this point in the pipeline, I don't need to know what they can do, just who they are. If a client submits both Windows credentials and a custom authentication ticket to a Contract/Binding on which I require just a custom authentication ticket, the service shouldn't be tricked into evaluating the wrong one. But perhaps at this stage in the WCF pipeline, the Contract hasn't been resolved so perhaps during this stage, all found identities/claims/tokens should be captured and selected among later. Is this right? How is this done?
Message Inspection: I have a custom MessageInspector which I'll still need for CORS support and OPTIONS request processing on some of the endpoints. I believe this happens after authentication and before authorization. In the case of OPTIONS, I set ref message to null and skip the Operation entirely, jumping straight to the BeforeSendReply. Clients don't send the auth-token on a CORS OPTIONS preflight request and so I allow these requests unconditionally.
Authorization: Depending on the Contract, I want to require certain authentication mechanisms and ignore others. I believe some setup needs to prepare the Thread Principal and Operation Context principal to the correct value. It seems that multiple Authorization policies can be in play at once. How do they interact?
Operation: I want to be able to implement each operation assuming that the identity of the caller is authenticated using a supported authentication (by Contract, which I'm OK maintaining hard-coded somewhere ONCE) and get the validated caller identity and assert simple permissions checks againsts the verified Claims.
How do I achieve this (code preferred over config xml)?
Thanks!

Application_OnPostAuthenticateRequest and Custom Principal Caching

I have implemented a custom principal approach as outlined here under Step 5: Using a Custom Principal
I then retrieve the user credentials from the database for use with the custom principal, but this results in a database call for every request, so naturally the answer would be to save my user object somewhere, either Session or Cache.
However, it would appear that HttpContext.Current.Session cannot be accessed from within
Application_OnPostAuthenticateRequest, so Cache would seem to be the way to go
The problem is these two answers here and here offer contradictory advice. The first one advises
No, don't use HttpCurrent.Current.Cache to store user specific information as the cache is common for all users and you will get conflicts. Use HttpContext.Current.Session instead as this will be specific to the user.
and the second one advises
Use the Cache instead of session
So which is the preferred method?
If Session is the way to go how do I put my user object into the Session object from the Application_OnPostAuthenticateRequest method.
If Cache is the way forward what problems will I face? For instance, is there a time limit on items held in the Cache? (I know to get around potential conflicts by using unique key from User object)
Not sure if your still looking for a answer but the best place to store the authentication information is in the Ticket.UserData property when writing the ticket.
I am assuming if you are using a custom provider that you are overriding the SetAuthCookie method.
If that is the case then that method will let you pass in the extra information for storing. It's common to store things like friendly username, roles, or other authentication details.
See this link for Setting UserData in Authentication Cookie

MVC Routing vs. Authorization/Authorize Tag

I am writing an MVC app that has two branches to travel along right from the beginning. On path authorizes with a PIN and I am using forms authentication to limit access to this section of the code. However, the other path will accept an AD log in and I need stop people from move between the branches using URLs. Should I be using a custom routing or should I create two separate authorization attributes to restrict access.
Thanks
You could use Roles to handle this with the existing AuthorizeAttribute. Simply put your AD-authorized users into a particular role, then in the paths that require an AD-logon set the Roles for that controller/method to require the AD role. This would entail implementing a RoleProvider which can seem somewhat daunting, but really isn't all that bad. Cache the user's roles in a cookie so that you don't need to look them up every time. The advantage here is that this will scale to additional roles as your application gets more complex.
Alternatively, you could extend the existing AuthorizeAttribute, overriding OnAuthorization and use your custom version. This attribute could check to make sure that not only is the request authorized, but that it has the proper credential type. The credential type could be stored in the session on login and retrieved from there for authenticated users. This is simpler to write, but doesn't scale as well.

Categories

Resources