WCF set bindings on service at runtime - wcf

My app has to be installed on my client's webservers. Some clients want to use SSL and some do not. My app has a WCF service and I currently have to go into the web.config for each install and switch the security mode from <security mode="Transport"> to <security mode="TransportCredentialOnly"> depending on the client's SSL situation. I am able to set the client bindings at runtime. However, I would like to know if there is a way to set the service bindings at runtime(on the server side).

Yes, absolutely! It depends on how you're hosting your WCF services. Saying it has to be installed on the webservers, I would assume you're hosting in IIS.
In that case, you need to create your own descendant of ServiceHostFactory - which really isn't that big a deal.
Your CustomServiceHostFactory is needed to return an instance of your ServiceHost, properly configured to your needs, to IIS.
In the CreateServiceHost method of the custom factory, you basically set up your ServiceHost and configure all its endpoints, behaviors, bindings, etc. - all in code, all under your full control. You can do whatever you need to do here, to configure your service just as needed.
In order to host your service. You'll need to adapt the MyService.svc file to include that CustomServiceHostFactory as the factory to use:
<% # ServiceHost Language="C#" Service="YourService"
Factory="CustomServiceHostFactory" %>
and that's it!
Check out Extending Hosting Using ServiceHostFactory on MSDN for more details, and see the A Custom ServiceHostFactory article on CodeProject for a sample.

Related

WCF Double Hop Localhost Losing Impersonation on Second Hop

I've seen a lot of posts about the WCF double-hop issue with impersonation, but none of them have specifically helped me resolve my problem.
What am I missing? What else do I need to do in order to retain my Impersonated User (DOMAIN\UserName) over on Service 2? I'm looking at ServiceSecurityContext.Current.WindowsIdentity.Name to confirm - maybe that's wrong.
The Setup:
Client App hosted in localhost IIS with Service Reference to Service 1 - Impersonating WindowsIdentity (DOMAIN\UserName)
Service 1 - WCF Service hosted in localhost IIS with Service Reference to Service 2
Service 2 - WCF Service hosted in localhost IIS
I'm using ALL basicHttpBindings to keep things simple. I've set up SPNs on both service endpoints.
I can successfully MAKE the double-hop and the code executes just fine
In Service 1 (hop 1) my ServiceSecurityContext.Current.WindowsIdentity is the person that I impersonated (DOMAIN\UserName)
In Service 2 (hop 2), my ServiceSecurityContext.Current.WindowsIdentity is the IIS App Pool user
ImpersonationLevel = "Delegation"
Both WCF Services have Windows Authentication Enabled and Anonymous Disabled
** Note: I'm running this all locally on my dev box. Even so, I've had my delegation level set to allow delegation from myself to myself. Maybe overkill.
Binding (similar for both services):
<binding name="...">
<security mode="TransportCredentialOnly">
<transport clientCredentialType="Windows" />
</security>
</binding>
I've set the impersonationLevel = "Delegation" on both the WCF service client and the service endpoint behavior configuration. My service methods are specifically decorated with impersonationOption="Allowed" (hop 1) and impersonationOption"Required" (hop 2).
As it turns out, the critical piece in my case was ensuring the following behavior attribute was set:
<serviceAuthorization impersonateCallerForAllOperations="true" />
Previously, when I set this value, I was receiving errors in Entity Framework, so I undid the setting. It appears that somewhere along the line of aligning my setup to the standard implementation (as described in other varios posts) that I was able to eventually set this attribute and have it work as expected.
Edit:
If this all works locally, but doesn't work in a distributed environment, check out this post: How can I fix the Kerberos double-hop issue?. You probably need to set the machines to trust delegation between each other.

Do I need to configure wcf with transport security if IIS is setup to negotiate certificates?

Even with all of the documentation available instructing me how to configure WCF to allow certificates over SSL, I'm having a hard time discerning where IIS' responsibilities lie and where the WCF's responsibilities lie.
For example, I do not have authority over my IIS server. I requested the admin to setup my virtual directory (application) to require certificates over ssl. I did this because when I tried to configure this security through my web.config, it told me that IIS wasn't setup to permit this.
After that, another developer told me that because the IIS Admin set it up this way, I only have to set security = none and client auth to none in my web.config because IIS will now handle this for my app.
Is this true? Also, is there documentation explaining the options of configuring IIS and WCF and some type of pipeline showing where these authentication processes occur?
Thank You.
Well, you definitely need to install a certificate and enable the SSL binding in IIS before anything will work. You must also set 'Security' mode to 'Transport', and 'clientCredentialType' to 'None'. This may be what your developer friend was getting at, though he is wrong to imply WCF doesn't need to do anything if security is setup in IIS.
<bindings>
<basicHttpBinding>
<binding name="secureHttpBinding">
<security mode="Transport">
<transport clientCredentialType="None"/>
</security>
</binding>
</basicHttpBinding>
</bindings>
You would then reference this binding in your service endpoint configuration. This page has a pretty clear step-by-step guide on what to do, though you will obviously need access to IIS to set this up.
The basic idea is that certificates are installed and managed by IIS, which also handles authentication. All WCF does is say what kind of security the service will be using/expecting. This page has a good discussion of Transport security over HTTP, as well as links to setting up IIS for this. Hope this helps!
I recently set up a wcf service for an outside company to access our data. The security practices are very hard to configure. I ended up bypassing the certificate and writing a custom auth class that authenticated a username and password in the header. Helpful references I found on my journey.
http://wcfsecurityguide.codeplex.com/releases/view/15892
http://msdn.microsoft.com/en-us/library/aa702565.aspx
I wish I could give you more my situation was not as vital for security so that had a major role in the route I took.

Create WCF Service to be hosted differently

I have a WCF service which programmatically creates its endpoints rather than using a config file - I'm looking into this as our field engineers are prone to break XML easily and we may use different types of binding in different scenarios.
This works well in self-hosted environments (console app, windows app) and as a Windows Service.
Can I do this with a service in IIS or do I have to provide a .SVC file for each endpoint ?
Also will the endpoint address from the client end have to include the .SVC extension ?
This is not a service intended to be used by third parties, only by our client components. We may expose parts of our API later but not initially.
If you're using .NET Framework 4.0 (and later), you can use the ASP.NET routing integration to define a service using a custom ServiceHostFactory implementation. A few things you'll need:
In web.config, set the attribute aspNetCompatibilityEnabled on the <system.serviceModel / serviceHostingEnvironment> element to true
Add a global.asax / global.asax.cs file, and in the Application_Start add a new ServiceRoute to the ASP.NET RouteTable.Routes collection. The service route requres you to define a new service host factory, where you can define your endpoints programmatically.
With that you'll be able to have endpoints without the ".svc" in their addresses. You can also use the service host factory without using routes, by creating a .svc file for each service (not endpoint), and using the Factory attribute in the <%# ServiceHost directive.
For more information about service host factories, check the post at http://blogs.msdn.com/b/carlosfigueira/archive/2011/06/14/wcf-extensibility-servicehostfactory.aspx.

WCF Service can not be accessed from another machine?

I have deployed wcf services in machineA and tried to accessed it through wcftestclient which is another system machineB. But i am getting error "The caller is not authenticated by wcf service". This wcf services is working fine when i testing it in machineA itself.
I have used wsHttpBinding.
How to solve this? Please help me.
on Machine A remove security if that service is only exposed in intranet.
Add binding configuration as follows
<binding name="none">
<security mode="None" />
</binding>
and In service add
bindingConfiguration="none"
If you don't want any security then only.
On machine B you'll have to supply some credentials that have access to the service on A.
See this article: Debugging Windows Authentication Errors for details, especially the section Client Credentials Are Not Set Correctly at the bottom of that document.

Authentication settings in IIS Manager versus web.config versus system.serviceModel

I have a WCF web service, and I want to use Basic authentication. I am getting lost in the authentication options:
In IIS 6 Manager, I can go in to the properties of the web site and set authentication options.
In the web site's web.config file, under system.web, there is an <authentication mode="Windows"/> tag
In the web site's web.config file, under system.serviceModel, I can configure:
<wsHttpBinding>
<binding name="MyBinding">
<security mode="Transport">
<transport clientCredentialType="Basic"/>
</security>
</binding>
</wsHttpBinding>
What is the difference between these three? How should each be configured?
Some context: I have a simple web site project that contains a single .svc web service, and I want it to use Basic authentication over SSL. (Also, I want it to not use Windows accounts, but maybe that is another question.)
The first two are really about access to an ASP.NET virtual directory or virtual application in IIS6 - that has basically nothing to do with WCF (WCF is actually not part nor dependent on ASP.NET). The settings control how the HTTP request coming into the IIS6 web server is being handled in terms of authentication. This basically controls whether anonymous callers from the internet can just call in without authenticating, or whether they need to enter username/password, or whether only callers with a valid Windows identity in this domain are allowed in.
The only reason this is interesting to your WCF service is the fact that when you host the WCF service in IIS (only one of the many options), then you have a (myservice).svc file that needs to reside inside a virtual directory. Of course, access to that SVC file is controlled by the authentication settings of IIS6/ASP.NET.
The security mode inside the <wsHttpBinding> section is the security-related definition of how the WCF service will communicate with its clients. Mode=Transport means, you're securing the actual transport layer - typically using SSL - not each message separately. This setting works great in Intranet scenarios where you have all clients behind a corporate firewall - but it won't work too well in Internet scenarios, since you can't really control the whole chain from the client (anywhere on this planet) over a series of intermediary hops to your server - you just can't. In this case, you'd have to use Mode=Message which basically encrypts and signs each message that goes over the wires - that works over any number of routers and relays along the way from the point of origin to your server.
The first two are related, if they don't match your service will not be able to activate. If you choose Windows authentication obviously there is an assumption that you will be tied to a windows domain or local machine.
Since you are going to be doing SSL basic authentication you are going to set this to None and then configure your transport security.
Your one stop shop for setting up transport + basic authentication
MSDN Article on Transport+Username + Windows Forms
I am not sure if you are still planning out how you are going to be doing security but i would recommend thinking about using message security versus transport(personal bias toward message security)..
Transport vs Message Comparison
Patterns & Practices on Message and Transport Security