I have written an IIS module (base IHttpModule) that does some custom (OpenAuth) authentication before preceding to my WCF REST service.
I have extended GenericPrincipal to track my user, with an IIdentity, and set
the context.User field to my new principal:
application.context.User = principal
However, when I receive the context in WCF (next step down the pipeline), the User shows up as a "default" unauthenticated WindowsPrincipal (not the GenericPrincipal that i set).
I see lots of stuff on the net about making this work (including aspNetCompatibilityEnabled="true" for serviceHostingEnvironment, playing with OperationContext, etc...) But nothing I have tried seems to work.
Two questions:
Is there a way to get this to work (or am I just barking up the wrong tree here).
What would be the canonical way to do this, or maybe the more "WCF" way to handle this custom authentication.
Thanks
You have to set your principal identity during the authorization phase in WCF. This requires a custom Authorization Policy. I suggest you read this article for more info. I've not tried to do this with a custom HttpModule and REST, but I have successfully done so with the default authentication schemes.
Related
I am implementing an OData endpoint on an ASP.NET application, and am working right now on the authentication part. I looked at the example at http://odata.github.io/WebApi/05-01-basic-auth/ for implementing HTTP Basic authentication. However, the example looks very weird to me, even though it the article gives an impression that this is how you implement generic custom authentication on a RESTful API.
e.g.:
It implements authentication on the stage of a pipeline where you are supposed to implement authorization. My understanding is that when OnAuthorization is called, you are supposed to already have the principal set and the only thing left to do is checking if the principal has enough access to perform the requested action.
What is the deal with that call to IsAuthorized? Isn't that supposed to be a side-effect free method?
So I basically would like to check from somebody who is more familiar with ASP.NET Web API to confirm if this is a) the correct way to do things b) a hackish but safe way to do things or c) something dangerous that should never be present in production code.
You are right, authentication should be implemented in separate AuthenticationFilter or even in HttpModule. You can find example here: authentication filter, http module.
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...
My server side contains WCF4 REST services and I'm going to add RIA services for my future SL4 application. Currently I'm doing Basic authentication like this:
var auth = HttpContext.Current.Request.Headers.GetValues("Authorization");
And so on.. You get the idea.. I call this on every request. If header not present or I can't validate UN/Password - I do this:
outgoingResponse.Headers.Add("WWW-Authenticate: Basic realm=\"Secure Area\"");
That got me by so far but I'm refactoring my server side. Implementing IoC for linked services. Created custom ServiceHost, ServiceHostFactory, InstanceProvider and all is well.
Now I need to figure how to properly handle authentication and authorization with WCF so I don't have to manually inspect headers. I do have my custom MembershipProvider so there have to be some method that get's UN/PW to process.
Any pointers? I looked at http://www.codeproject.com/KB/WCF/BasicAuthWCFRest.aspx but it uses RequestInterceptor and it is not available in WCF4. I found ServiceAuthenticationManager and ServiceAuthorizationManager but there is no samples available on how to code and wire those..
Can anybody suggest which way I should go?
Try to use this custom HTTP module. It will add new authentication mode to IIS and it will allow you using custom credentials validation.
I had all types of issues using the built-in annotations for WCF in a recent SOAP/C# project. I know this isn't the best solution, but for my purposes, I enabled basic authentication in IIS7 for my application, disabled anonymous authentication and created Active Directory users for the external clients that would call the web service endpoints. I then changed the application's permissions in IIS7 (it uses file system permissions) to allow a group containing those users.
This moves authentication outside your application, which may not be what you want, but does allow you to easily add users via the IIS7 console and deployment tools that can copy those permissions. The advantage is that you don't have to redeploy your application for permission changes. The disadvantage is you can't do fine grained permission control per function.
I have this existing environment:
1) ASP.NET 3.5 web application
2) forms authentication with the SqlMembershipProvider
I need to add the following:
1) a Silverlight charting object embedded in a web page.
2) a WCF service to be consumed by:
a) the Silverlight component embedded in an authenticated
web page, as mentioned above
b) server-based WCF clients with certificate based authentication
My question is - what is the easiest/best way to configure the WCF endpoints for the Silverlight object to authenticate to the WCF service using the security context of the already logged-in user (via the page that’s hosting the Silverlight object) without having to use the user's username/password again?
I've researched a lot of the MSDN and Patterns & Practices material and I thought I had a decent grasp of many of the potential authentication scenarios. But I can't seem to figure out a way to tie them together for the scenario I've outlined. I've found other people posting similar questions to mine but none of the answers I've read seem to fully answer their questions either. (Maybe I'm making this harder than it needs to be?)
I would think that the solution would be to somehow use the authentication token/cookie generated in the asp.net form login and somehow pass that to the Silverlight object which then includes it in the WCF request. But I don't see how to configure the WCF endpoint to use that token.
(In some of my other projects I've implemented the server-to-server scenario in 2.b above using certificate-based authentication, so I'm not too worried about adding that to the current mix I've outlined.)
Thanks in advance for any insight or pointers to the path forward.
Terry
Thanks codemeit for trying to help but I finally figured out what I was doing wrong - it was pilot error.
In trying to configure the endpoints for my Silverlight app I was testing with an asp.net page. I finally realized that when I test that way, the client endpoint is no longer originating from the authenticated browser - the client endpoint is the IIS server which in turn executes the request against the WCF server endpoint. So the security context changes and HttpContext.Current.User.Identity is always empty at the WCF server endpoint.
Once I got my test SL app running in the browser, it automatically inherited the security context of the authenticated browser and then HttpContext.Current.User.Identity was correct and authenticated at the WCF server endpoint.
Have you tried to enable your WCF services with aspNet compatibility, then see if the following is true.
string currentUserName = HttpContext.Current.User.Identity.Name;
bool isLoggedIn = HttpContext.Current.User.Identity.IsAuthenticated;
if these properties are being populated with the expected values, then this is the one you are after.
To enable aspNet Compatibility
add to web.config
<serviceHostingEnvironment aspNetCompatibilityEnabled="true" />
add to the service impl class
[AspNetCompatibilityRequirements
(RequirementsMode=AspNetCompatibilityRequirementsMode.Required)]
In this case, the endpoint would be using basicHttpBinding, and you could check the authentication at run time within WCF.
Is there a clean way to expose a WCF REST service that requires basic authentication, but where we handle the actual validation of the username/password ourselves? It seems that when you tell WCF in config that you want to use basic authentication, it forces you to turn on basic authentication in IIS and IIS can only do basic authentication against window accounts.
The only hack we have found is to lie to WCF and tell it there is no security on the service and then do authentication outside of the WCF stack using a generic IHttpModule (which has a proprietary config file to indicate which URLs have which authentication/authorization requirements).
It seems like there should be a better way. Anyone have one?
The WCF REST Contrib library enables this functionality:
http://github.com/mikeobrien/WcfRestContrib
It also allows you to secure individual operations.
is the username and password set on the client like:
cc.ClientCredentials.UserName.UserName = ReturnUsername();
cc.ClientCredentials.UserName.Password = ReturnPassword();
Or are they embedded in the body of the REST message?
If the former, you can use a custom UserNamePasswordValidator:
http://msdn.microsoft.com/en-us/library/aa702565.aspx
If the latter, you can set the service to no security, and use a custom ServiceAuthorizationManager to validate the contents of the message:
http://msdn.microsoft.com/en-us/library/ms731774.aspx
Hope one or the other helps! I'd try to post sample code & config, but I'm # home and dont have access to code, which is all # work.
See Custom Basic Authentication for RESTful services. Pablo's approach uses the interceptor functionality that is provided via the REST starter kit to solve the problem. If you do not want to depend on the REST starter kit, then you can create your own service host and use the inteceptor functionality provided.
If you host it on IIS, using custom http module is the way to go. You can bring over the principal over to WCF side to do code access security. See HTTP Basic Authentication against Non-Windows Accounts in IIS/ASP.NET (Part 3 - Adding WCF Support). Also see Custom HTTP Basic Authentication for ASP.NET Web Services on .NET 3.5/VS 2008.
If you are not using IIS, you should be able to implement userNameAuthentication. See Finally! Usernames over Transport Authentication in WCF.
Yes absolutely there is a way. You need to configuring a custom userNamePasswordValidationMode value for your service and point it to a class with an overridden method that can inspect and validate the credentials provided. When making a RESTful call, these credentials when using Basic authentication in its proper form should be in the request header. With this custom method you can inspect the credentials and then authenticate the client to your service. No Windows accounts or domain even needed.
The nice thing is you can then take that security context to the next level and provide fine-grained authrization at the method level. You might have instances where a large pool of clients are able to access the service, but not all methods within (i.e. paid clients vs. unpaid). In this case you can also provide authorization at the method level as well if needed.
Below is a step-by-step solution (with too many steps to embed) by me that contains both the needed configuration and security required to have a complete solution. The problem is often Basic authentication is used without securing the Transport with a SSL certificate and this is bad. Make sure to follow all the steps and you will implement Basic authentication without the need of any type of Windows accounts or configuration on your WCF RESTful based service.
RESTful Services: Authenticating Clients Using Basic Authentication