My scenario is that I have to expose some API over WCF to third party clients. I wanna use the most secure option. Ideal solution would be making a windows account for each client in my server active directory and letting them access the service with Transport & Message security and Client credentials username. So I could ask the client to provide username and password and use windows group policy to role base authorization.
Since this is an internet facing WCF service, I'm not sure I could use windows accounts??? Should I be using database solution to manage usernames, pwd and roles?
Should be able to consume from .NET clients as well as Java clients. Third party clients could be anything that can consume soap.
What's the best security option to this scenario? VPN is not an option as this totally should go over internet. Your help is very much appreciated.
It sounds like what you need is some kind of a token based authentication setup. Microsoft seems to publish the best material in the game for this kind of thing. You can find their articles here and pick the scenario of security that most closely matches your needs:
Microsoft WCF Security
you can use ASP.net membership with form authentication for your service.
using windows authentication for internet facing service is not a good idea.
for more information:
How to: Enable the WCF Authentication Service
Windows Communication Foundation Authentication Service Overview
Securing WCF with Forms Authentication
Related
I need to find a way to authenticate/authorize users in a WCF-service. I'm using an external authentication service which stores the credentials of the users.
Eg. "Bob uses our loginmethod, we send the credentials to the authentication service, the service lets us know if these credentials are correct."
If Bob sends another request, we need to know if Bob is already authenticated.
Now a session is being created on the client, but it needs to move to the server-side. We can not rely on clients for security.
Can this be solved by using security cookies or do any of you have a better suggestion?
EDIT! I can only use the authentication server and do not have access to it
The problem you are describing is a well-known one that had (at least) two standardized solutions.
Federation using WS-Trust
The first option is a SOAP based one that uses active federation based on WS-Trust. In this solution:
Your client provides credentials to the authentication service
If the credentials are valid, the authentication service returns a signed (and encrypted) token to the client. It is encrypted so that any information contained in the token remains confidential - even the client cannot read it. It is encrypted with a public key belonging to the your WCF service. It is signed with a private key belonging to the authentication service.
The client submits the signed/encrypted token to your WCF service. The service can decrypt it because it holds the private key for decryption. It can trust it because it is signed by the authentication service.
Based on the content of the decrypted token, the service can establish the client identity and make an authorization decision.
In this model, the usual terminology is:
Your authentication service the Security Token Service
Your WCF service is the Relying Party
your client is the Client
This sounds complex, but it is very well supported in .Net and WCF using Windows Identity Foundation. There are many samples available much of it (maybe all) can be done via WCF configuration rather than code.
This is well suited to scenarios where the clients are crypto-capable (like your .Net clients) and where good frameworks exist (like WIF). It is not so good for low spec clients such as browsers and some phones, or where you are not in control of the clients.
It is commonly used in enterprise scenarios, including enterprise-to-enterprise federation. It is used less often in internet scenarios.
the strengths of it are
It is standardised and therefore generally well supported by frameworks
It means that your WCF service never has to handle the client credentials (= more secure)
It makes it pretty easy to switch to different authentication services (because it is standardised). For example, on-premise AD and Windows Azure AD both support this, as do other independent identity services
An overview can be found here:
http://msdn.microsoft.com/en-us/magazine/ee335707.aspx
And Google will show you lots more walkthroughs and examples.
Federation using OAUth 2
In this solution:
The client displays some UI provided by the authentication service (generally a web page)
The user enters their credentials in that UI and the authentication service authenticates and eventually returns a token to the client. The nature of the token is not standardised, nor is whether it is encrypted. Generally it will be at least signed.
The client submits the token with each request to the WCF service
The WCF service authenticates the token as in the previous solution
In the OAuth terminology:
Your authentication service is the Authorization Server
Your WCF service is the Resource Owner
Your client is the Client
Again, this sounds complex, but it is reasonably well supported in .Net. Probably not as well as the WS-Trust approach though at the moment. It is supported by Windows Azure AD and on the client side, using the Windows Azure Authentication Library. May other services use this approach - e.g. Facebook.
This works well where
Your client is low spec or not crypto-capable (e.g. a browser or some phones)
You do not control the client (e.g. a third party application is accessing your service)
It is very commonly used in internet application where you as an owner of the WCF service don't necessarily know the users or the clients. It is a less complete standard in some ways (e.g. it does not define exactly how the authentication happens) and as a result, it is less easy to switch to alternative authorisation servers.
The strengths of it are:
It is simpler and therefore has wider platform support
It is growing in popularity and therefore the library support is getting better all the time
The user never enters their credentials into your UI, only into the auth server, so it is more likely to be trusted (in internet scenarios)
It has a built in way of controlling the scope of the permissions granted to the client, and revoking those permissions, so again it is more trusted in an internet scenario
The official .Net support for this is in the Windows Azure AD Authentication library
http://msdn.microsoft.com/en-us/library/windowsazure/jj573266.aspx
There are other, open source components too, such as DotNetOpenAuth
http://dotnetopenauth.net/
Which solution would be best for you depends mainly on the nature of your authentication service I would say. And on whether you are in an enterprise or internet scenario. If the auth. service could be easily adapted to be a WS-Trust Secure Token Service (STS), then that would be a good route. If adding some web UI to the auth. service is feasible, the OAuth might be better.
Or, if neither option is feasible, you could just borrow the patterns form one approach and use that without going for the full standard.
Good luck!
We have started looking at this tutorial to use the new notifications hub in Windows Azure:
http://www.windowsazure.com/en-us/manage/services/notification-hubs/notify-users-aspnet/
At one point it specifies a warning stating:
"SECURITY NOTE
The AuthenticationTestHandler class does not provide true authentication. It is used only to mimic basic authentication and return a principle. The user name is required to create Notification Hub registrations. The above implementation is not secure. You must implement a secure authentication mechanism in your production applications and services."
Can anyone suggest a good way to secure this that will work from windows phone, android and iOS. We can't use the built in authentication such as facebook, google, twitter, etc. as it needs to use our own authentication backend.
Many thanks for any help.
To implement cross platform authentication it's best to use a standard like OAuth2.
OAuth2 allows you to
Handle logins in one place on server side.
Your clients only get as few account informations as needed. It's possible to hide the password from clients (whereas not common in mobile apps). Each client gets it's own unique access token.
Remove access remotely by revoking access tokens on server side.
For implementation:
Apache Oltu is a Java Framework for OAuth2 authentication (server and client support).
Udi wrote a very good tutorial for Android authentication.
I'm setting up a WCF service. The service has to use transport security over https and I need to use some kind of authentication to prevent unwanted usage.
Digging in to WCF theory has disapointed me so far.
What I have found out so far is that I can use UserName authentication with transport security. But then I will need a certificate to secure the message.
And this makes it difficult to consume with most .NET languages.
I am surprised that I cannot find any good information on how to authenticate a user with wcf without message security?
What I would like is that the client passes username and password in some way to my service.
And for the record. The service will be using transport security.
To break it down:
How can I implement authentication without limiting interoperability?
Is WCF services so cumbersome that I either have to use a completely open service. And use IP filtering or VPN to restrict access?
UPDATE:
Since I am planing to use https with a SSL sertificate, will security mode "TransportWithMessageCredential" be the solution for me?
The only way to get REAL security IS to use digital certificates.
See my own question on this topic for details.
TransportWithMessageCredential (AKA mixed-mode security) is indeed what you are looking for.
I'm building an app which is subscription based, users can login to a website an use it as they please. I would also like them to have the option to work with it outside of the browser and even offline. The app itself is not dependent on online resources, only the authentication is done via forms authentication.
What would be the best way for me to make offline authentication possible?
You could consider using WCF RIA Services for authorization and authentication with your own membership system.
Here is a brief example.
Is it possible to use Brokered Kerberos Authentication for web services over the Internet? I'm looking at web services security for an environment which already has Active Directory. Due to the existing architecture the web services will be quite chatty and I have no control over this architecture. It may take up to 6 web service calls to perform one business process .
There is concern over authenticating multiple times and the overhead this will incur. From my initial reading of brokered kerberos authentication, once the user credentials are provided then a Kerberos security token will be returned and authentication is not required for each web service call.
I'm envisaging a system where the user credentials are passed to Active Directory via a web service call and the Kerberos token is returned. This token is then used for all subsequent web service calls.
Is this possible or am I heading off on a tangent? If I am heading off on a tangent is there a preferred approach for this? I've finished reading the Microsoft Web Service Security: Scenarios, Patterns and Implementation Guidance for WSE 3.0 and still a little unclear.
Consider leveraging the SAML protocol as a way to exchange assertions via WS-Security.