WCF service to handle Authentication and Roles - wcf

I am trying to create a simple WCF service to handle various security scenarios, but am not really sure where to begin.
The WCF service will be hosted on IIS (most likely). It needs to be accessible by both authenticated active directory users and non-authenticated users (anonymous/external). I need to be able to access various methods for both types, though the authenticated users should have access to additional methods.
I would like to be able to check HttpContext.Current.User.Identity.IsAuthenticated (I assume this would be the easiest way to determine which type of user - or would it be ServiceSecurityContext.Current.WindowsIdentity) and access a roles database. The service will be accessed by both a .net 4.0 website (not webforms app and not mvc) and other external sources that may or may not be .net (java app or java web site, for instance).
I am unclear as to where to begin. What type of binding(s), transport(s), security mode(s). Can I use a membership/roles provider (SimpleMembership or the older asp.net membership) with the service?
If I want to have different types of anonymous users, do they need to be mapped to a specific active directory users for different roles or can I also include some sort of username/password to authenticate?
I also need to be able to use impersonation, so that assuming the correct rights, actions performed by one user can appear as if done by another.
I have been looking at various options and getting confused. ADFS, WIF, Microsoft.IdentityModel.dll, ACS 2.0, etc.
Not sure what is best, what is overkill, what will and will not meet the needs, what will be relatively easy to implement. Use SSL or not, and if so, how to setup both the service web.config as well as the client web.config
I know this a lot to ask, but at least if I get pointed in the right direction, I can stop looking at solutions that will not work or are overly complex and focus on the right solution(s).

Related

Need to authenticate users through a WCF service that is connected to a database

I'm getting increasingly frustrated with doing the authentication right. Usually I'm using terms that I'm not familiar with so answerers misunderstand my questions. Its not helped bu the fact that this is a case with many implementations.
So now I'm going to try to explain the facts and requirements surrounding my project so that I might get a pointer towards a good solution.
I will have a Database that includes the information I need. Included in this info will be the usernames and salted hash of passwords. This database will be connected to a WCF web service that supplies the data to other front end projects.
One of the front end projects is a asp.net MVC 3 web site that users will use to log in and such. Now the default in such a project is some sort of SQlMembership that is not right in this case as this site is not connected to the database (it might not even be a MSQL database).
Here are implementations that I looked at but couldn't quite figure how to use correctly.
1) Write my own MembershipProvider in the MVC project that would query the WebService for validation. Here I mean that it would just call some methods for all its needs. Not liking it for security issues, client side solution.
2) Validata using a service side MembershipProvider but then I would have to send userName Password with each action and I can't store password for security reasons.
3) Then I discovered something called WCF authenticationService http://msdn.microsoft.com/en-us/library/system.web.applicationservices.authenticationservice.aspx and it seemed to be what I need but I'm having problem understanding how it works. I wan't it to be part of my service but it seems to be a dedicated service. Also its not really explaining how it authenticates (I need to have a custom authentication based on my table, not some default table created for me). Here is a post Should authentication be in a separate service for wcf? with same problem that I'm not sure how got solved.
Can the WCF authentication service be the right tool for me?
Can you answer this for someone who doesn't know asp.net, web or service terminology?
EDIT
Here is one solution that I was hoping for but not sure if exists.
The WCF Service exposes a MembershipProvider, RoleProvider, ProfileProvider that are defined in the service.
In the MVC web.config under membership\providers\add the MembershipProvider is added along with a endpoint towards the service. Same with RoleManager etc.
So when I call MembershipProvider in the MVC project to validate user it automatically calls the service and checks there and when it happens upon a Authorize attribute it as well checks the RoleProvider in the service automatically.
I would however also want to restrict the service calls themselves, even if they are inside a [Authorized] attribute method it might not be so in other clients that reference the web service. Would love if when a call comes from a website the service would automatically have access to the forms.authentication cookie.
I am not clear as to what you want to authenticate exactly, if the user login in, or the user accessing you service. Also, I am not sure how you mean for an answer about WCF Security not to use service terminology nor how you expect to solve this without knowing asp.net. I'll do my best though.
If you are authenticating a user login in, you can implement your own MembershipProvider and have a service request credentials and return the authenticated user.
Once authenticated, you can assign each user a GUID. This GUID is the ID which will travel with each message (encoded in the message header) and validate the user to call the service method.
This doesn't involve transport security, which you should configure if you want your message to be secure over the wire, yet this is a different matter, not involving authentication.
Hope this can somehow help you. I tried to make it the least technical possible and left out anything too complicated. Hope this helps somehow...

Authenticating call to WCF / Web Service from ASP.Net MVC

Basic question here (I think), I was hoping someone could point me in the right direction. I don't know much about WCF but I'd like to create a web service to be called from an ASP.Net MVC application. The goal is to make sure only authorized ASP.Net users (we're using forms authentication) can call the web service, not just anyone. Are there tutorials out there I can look at on how to approach this? Many thanks.
I assume from the question that you don't care what the end (MVC) user ID is that is hitting the WCF service (in other words you don't need a specific authenticated user to hit the WCF so you can get the ID of that specific user (i.e. so you know that joeBobUser hit the WCF)). you just want to make sure that user is authenticated and authorized to use the site. You don't need every potential user of your MVC app to be authenticated/authorized.
As long as that is true, then my approach would be as follows:
run your MVC app as a specific, known user account (i.e. set up the app pool in IIS to runas a domain user such as yourdomain\youMvcAccount) instead of the default asp account. There are lots sites that have instructions on how to make this happen if you are not already running your mvc app as a domain user.
set up your WCF service endpoint configuration binding as WsHttp. Again, many sites describe how to do this. here's one that does it via GUI (I prefer hand-editing the config but whatever). So now your WCF service will only accept secure, authenticated requests
create your WCF client proxy in the MVC app. easiest way to do this (probably not best re: separation of concerns, but just to get started) is just add new web service and discover you WCF endpoint that way. Again, basic stuff easily googable if you don't know how to do that.
Now your MVC app will be making the call to the WCF service authenticated. However, at this point, any client authenticated in your domain can call the service. You are now accepting ONLY authenticated but ANY authorized user. All calls issued from your MVC app hitting the WCF will be from the identity yourDomain\yourMvcApp
Restrict authorization to the identity set in #1 restricting (authorizing) authenticated users can be done a number of ways. The get'r'done fast way (but not very flexible as any change requires recompile) is just to check the identity of the request is the same as the identity of your WCF service directly in your service call. Alternatively, you can set up more robust (with the concurrently more goo) options such as AzMan or other WCF authentication rule sets. Again, many sites have instructions on setting that sort of thing up after you have an authenticated user. Here is a SO question that limits authorization to a windows group post (I'd do it that way--more flexible but you need to add that user to a group on your domain), and another article that goes more into the details of WCF security and allowing only a specific user access to the service.

wcf data service security configuration

I'm in the process of setting up a WCF Data Services web service and I'm trying to sort out the security configuration. Although there's quite a lot of documentation out there for configuring WCF security, a lot of it seems to be outmoded or does not apply to my scenario.
Ultimately, I am planning on managing authorization of operations via change interceptors. Thus, all I really need is the simplest way to permit a client to pass credentials along with a request and to be able to authenticate those credentials against either AD or an ASP.NET membership provider (I'd much prefer the latter unless it makes things much more complicated).
I'm intending to manage encryption at the transport level (i.e. HTTPS).
I'm hoping that the eventual solution does not involve a huge web.config. Likewise, I'd much prefer to avoid writing custom code for the purpose of authentication.
In the following links you have a series of OData authentication options. If you don't know exactly what you want then that is a really good place to start and see what options you have.
Part1
Part2...

Will this WCF setup work?

I'm rather new to the WCF/IIS/MS web stack corner of the world so I'm hoping for some help evaluating my design.
What I need is a system that presents a number of resources as URIs. Each resource is a WCF web service providing a number of read and write operations. I need to provide username/password security for different resources.
How I'm hoping to make this work is to have IIS handle the security using the normal devices it uses for everything else. Then uses URL rewriting to remap everything to a single web service that will provide the correct resource based on the rewritten query string.
Will this work?
Am I missing something?
Is there a better way to do this?
If you happen to known of a really good tutorial for the bits and peaces (like what file does the security settings go in?) I would appreciate links?
For now there will be only a handful (2 to 20) users so static config files would be preferred for that as along as it won't cause problems later.
As I said, I hardly known jack in this domain so I don't really known what I don't known.
A few links I have found (don't even known yet if I'm looking in the right direction)
Fundamentals of WCF Security (assumes a bit more familiarity than I have)
Improving Web Security: Scenarios and Implementation Guidance for WCF (really long, book length)
Yes this sounds sane. For authentication you want to use ASP.NET membership module it provides a generic security API which can use intergrated (windows user), web form login, even LiveID or some custom authentication. In my experience MSDN has proven a good resource, here's a hands on article.
For web http binding WCF provides Uri rewriting out of the box using WebGet attribute.
for SOAP, the end point URL is the same, so I assume you want RESTful endpoint. If so, you need Basic auth over https not WS-Security.

Securing a WCF service so that it can only be called by a Silverlight application

I am writing a Silverlight application that will be both reading and writing data to a serverside database via some WCF web services.
What is the best way to secure these web services?
My goal is to make sure the services can't be called by other applications and potentially spammed with requests to add items to the database. Only the Silverlight application needs to be able to access them.
Don is absolutely right that there's no foolproof way of making sure that the client is a Silverlight application.
However, I think you're asking more about the following: Can I make sure that only people I trust connect to the service.
The answer here is (basically) a yes, or at least we have standardized ways of doing this.
You're typically going to want to consider a couple of different approaches:
Transport level security. Has somebody tampered with the traffic? We use SSL for this.
Authentication. Am I talking to someone I trust? Here, we'll typically use one of the authentication mechanisms (Forms Auth, say). You can use Forms Authentication to secure both Silverlight (actually the page that Silverlight resides on) and the WCF services. Confusingly, SSL can be used (though rarely is because it's a pain in the neck) for authentication.
In general, you can't assume anything about the client. If you try to keep non-Silverlight apps from hitting your site, a malicious client can easily pretend to be a Silverlight app, and you're back to square one.
That is to say, this is not an effective way to secure a server. To secure your server, assume that any and all clients will hit your site, and start from there.
Edit:
Let me amend that to say that if you want to get into the world of mutual authentication, you can set up a PKI to manage certs, issue user certs for all your users, and then you know who your users are. Still, one of them might be malicious (and talented) and inject a cert into another client.