Authenticating processes calling a WCF service - wcf

My team is gutting a bunch of legacy code and forcibly inserting a service layer. It's a combination of .Net, VFP, ASP, and ASP.Net. Ugly COM objects and other bad practices.
We're moving logic from the libs and UI into a WCF service a module at a time. We have to authenticate the user making the call, but we also want to authenticate the process that's making the request. We don't want anyone who can access the services to be able to write scripts or apps that call our services that we don't know about.
Other than writing a custom ISAPI filter and hacking the request before send, is there a "normal" approach to locking down services to prevent anyone with a browser from making calls directly against a WCF service?

Related

authentication and authorization design in RESTful web application

I have an web application built using RESTful services (JAX-RS).
There are REST calls, and simple JSPs with js files to handle data.
Now I want to implement authentication and authorization in service. What I did earlier was to implement simple filter and inside each service check for #HttpRequestContext for if session has user object. Since it I want to expose service to say, external webapp, I will have to hard code system as there is no standard.
I feel this is not good design. Is there a design pattern to solve this common issue ?

Is it really worth using the WCF REST Service Application type in Visual Studio 2010?

In the past, I have created a "robust" WCF service that can accept a complex (consumption of the service in a project) or RESTful requests.
I'm creating a new service and wanted to ease the creation of the restful endpoints. So I see the WCF Rest Service Application, which I'm trying out.
The problem now, is that if I wanted to use this service from another .Net application, I would now have to go through the process of writing the completed event parsing/de-serialization.
I think in trying to over-simply the initial process, I will complicate the consumption process.
Are there any simpler ways around this, and is it best to stick to the main WCF service type and simply decorate the service contract methods appropriately.

RESTful Workflow Service Endpoints in WF4 / WCF

Folks,
I'm building a pretty standard workflow that I want exposed via a WCF endpoint - I'm using the "WCF Service Application" project template and I've got a .xamlx service. This is a very simple document interchange workflow service - I want consumers to POST me a blob of XML as the body of an HTTP post (with HTTP headers containing authentication tokens). In response, these consumers will get a blob of XML containing the reply. 2 goals for me using REST/POX here are the document/message-based nature of the interaction AND I want to make client development easy for non-.NET environments (especially limited environments like Silverlight and iPhone).
I don't really see how to make this possible using out of the box features (unless I'm missing something). Does anybody know how to create a RESTful (or even REST-ish, I'm not picky) endpoint for a WF4 service-hosted workflow? Any info leading in the right direction here would be great.
There is an unreleased item on CodePlex to cover this, which includes source code. Also see this SO answer which contains another idea for achieving this.
If you'd like to see the CodePlex activity released, please up-vote the UserVoice request.
Using a REST Pass-Through Service
As #Maurice mentions, you can also treat the WF service as a back-end service and expose a REST service that simply calls through to the WF service.
This method is a bit clumsy, but has the advantage that it doesn't use anything unreleased or really complicated.
If the back-end service runs on the same machine as the REST service (which is probably what you'd do), you should expose the WF service using the named pipes binding. This binding is fast, but only works when the caller and callee are on the same box.
A further thought: your REST pass-through service is blocked while the back-end service is being called. If your WF service is not very fast, you'd benefit from making your REST service asynchronous so it doesn't block a thread pool thread while the WF service is being called.
There are no out of the box activities that will allow you to use REST with WF, the Receice is pure SOAP.
You can either build a custom REST Receive activity and use that with your workflow. Depending on your needs this is going to be quite a handful to a lot of work. The easy option is use use a standard REST WCF endpoint and convert the REST data to SOAP, pass rhe request on to the workflow, and do the reverse on the result message.

Security of WCF endpoints

For the sake of argument, lets say that I've got a basicHttp WCF service. Besides implementing authentication (login/logout methods), what is stopping someone from just cracking open Visual Studio, adding a web reference to my website's service, and then playing playing around with my service? I'm not familiar with a method of stopping someone from doing this. The idea of someone downloading all of my Data/Operation contracts and then start playing around is keeping me up at night, and I like my sleep!
Discoverability is the driving factor behind Web Services and especially SOAs. The ability of anyone at all who can reach the service to pull up the WSDL, generate a proxy in Visual Studio (or some other tool), and start using the service is one of the main reasons to create a web service!
I suppose you could generate all the client proxies and then disable the mex endpoint, but that pretty much cripples WCF, and even then it's only security through obscurity.
If you don't want any miscreant to start hitting your web service then either don't use the basicHttpBinding (which is designed for the express purpose of immediate and anonymous consumption) or host the service on a private network which only trusted clients can reach.
Some form of authentication or encryption is the only thing that can prevent this. You have to distinguish between those you want give access to, and those you don't. Give the ones you want to have access the certificate necessary to do encryption, or the username and password.
Don't give anything to the others.

Which to use...REST, ASMX, WSE or WCF?

I have a Windows Service which performs a certain function, and then needs to send that information off to a webservice for processing. The webservice is hosted by a remote web application. I am trying to ascertain the best way to call the webservice(s) as each web application might be only 2.0, or 3.5 etc. In my windows service, I am defining each "client" in the app.config, e.g.
<Client WebServiceUrl="http://location.com/webservice.svc" Username="" Password="">
</Client>
The web application must implement two web services that are required for my windows service to run, however not sure the best way to implement the "rules" for the web application.
EDIT:
I'll try and rephrase..
The Windows Service runs every 30 seconds and obtains a list of information. The service supports multiple "clients" as shown above. When each client process is run, the data is collected and is then needed to be sent to the supporting web application.
The windows service does not know what to do with the data, it is just sending it. Each web application for a client would be in different locations, and could possibly be built in 2.0, 3.5, PHP, etc. All the windows service cares about, is that when it performs its processing for a client, it is able to send the data to the webservice location defined in the app.config of the windows service.
What I'm trying to determine is how to connect to the webservice (which I'm leaning towards WCF, however Basic or WS not sure), and what rules need to be defined for the web application in how to build the response.
If the Windows service is to support php applications etc, WSHttpBinding would not be an option, which would mean BasicHttpBinding would then work. The other thing to decide is whether or not to utilise a RESTful service or SOAP service.
Hope this makes more sense.
I'm not really clear on what you are doing.
It seems like you have 3 things: A Windows Service, and then a web service, hosted in a web app.
I think your question is, what to use, REST, ASMX, WSE or WCF, when interconnecting the Windows Service app with the remote web service.
ASMX, WSE and WCF are alternative programming models for the web service. REST is not a programming model. It is not like the other three.
ASMX and WSE will require that you use Web services and SOAP.
WCF can allow you to use Web services and SOAP, REST (XML or JSON) over HTTP, or a binary format over TCP, among other options.
Because it is flexible and current technology, I'd recommend WCF. ASMX is now termed "legacy technology" by Microsoft. Doesn't mean it won't work, but it will not get updates. (Much like WinForms versus WPF). WSE is no longer in mainstream support, as far as I know. For these reasons, I wouldn't recommend starting a new project on WSE, nor on ASMX.
WCF is more general than ASMX and can seem more complicated, for that reason. But once you make some choices and zero in on what you want (for example choose HTTP and REST, or choose binary and TCP), it's more powerful. WCF can be used as the programming model on both the client or sender (in your case, the Windows Service, I guess) and/or on the server (the web service hosted in the web app).
Using WCF on the client side does not imply you must use it on the server side, and vice versa. On the other hand, if you control the source code on both ends, I would recommend using WCF on both sides.
As for "how to implement the rules for the web app" - I don't understand what you are asking there. Maybe if you are more specific on the question there, someone will be able to help out.
Update: Based on your additional explanation, I'm going to suggest you look at the REST stuff in WCF for .NET 3.5. In PHP it's very easy to implement a REST-style service, and with WCF, the same is true for .NET. Now in your case the Windows service is the client and it is sending out a request, an update request, to various servers that reside on your customers' networks. According to REST principles, I'd make those outbound requests PUTs or POSTs, depending on the semantics of the call.
Then you could ship some example service code to your (uppercase) Clients, to get them started on building what they need to receive your outbound PUT/POST messages.
Security is a concern though. You didn't mention it at all, which is surprising. Security is not one of those things best deferred, so that you "add it on later". You should think about it early - it may affect the protocol choices you make. For example, if you need to mutually authenticate the clients and servers (the latter at your "uppercase" Clients' networks), then you may want to go with SOAP, which gives you good options on the protocol side for security. Secure Web services extensions (WS-Sec, etc) are well supported in WCF, but not sure about the status of this capability in PHP.