Wcf how to verify the caller identity? - vb.net

I have a vb project and a WCF service. When I install the project on a different computer every time, how can I verify the identity of each caller without login and I research in microsoft website
https://learn.microsoft.com/en-us/dotnet/framework/wcf/feature-details/service-identity-and-authentication
and I try to set SSL to verity but this way doesn't seem to be getting caller's identity
https://learn.microsoft.com/en-us/dotnet/framework/wcf/feature-details/transport-security-with-certificate-authentication
It any way to get caller identity without login and sample code to refer?

As per your question on SO, I think you should reconsider this. You can't prevent clients from calling your service with the same username and password. So what is your client identity? You can use transport layer security and use certificates as credentials to determine the identity of the caller.
Please refer to the following link.
https://learn.microsoft.com/en-us/dotnet/framework/wcf/feature-details/transport-security-with-certificate-authentication
https://learn.microsoft.com/en-us/dotnet/framework/wcf/feature-details/how-to-use-a-custom-user-name-and-password-validator
https://learn.microsoft.com/en-us/dotnet/framework/wcf/feature-details/authentication-in-wcf

Related

WCF Security - Newbie questions -

I've been reading about WCF security for a whole day and can't say I'm comfortable with it.
I've developed some WCF services and deployed them to a test server and can call from a client. Both sides C# / VS 2010. The services are hosted under IIS 6. No option to go more recent at the moment.
So - I've read that I can only use HTTP with IIS 6 - which I believe restricts me to basicHttpBinding or wsHttpBinding as the binding.
I've also read that the XML sent over the wire using wsHttpBinding is encrypted, whereas basicHttpBinding is not.
So it looks like I want to go with wsHttpBinding as I will want some sort of authentication and I suppose user name / password will be passed along with the incoming messages.
First question is - if I use wsHttpBinding do clients have to call using https? And then do I need to worry about certificates etc. on the server?
Second question is - what security options are available to me? Do the callers have to be Windows users on the server, or can I make up my own user name / password and have that part of the service and the service do the validation and have nothing to do with Windows users? If I have to go with Windows users I suppose it's common to set up one user account on the server and have all callers use that?
The basic idea is I need to open this service to selected callers, but don't want just anyone to be able to discover the service and call it. I need to control somehow who calls the service. Is user name / password the standard way of doing this? Could I define a GUID for example which all callers would have to pass?
In answer to your first question. wsHttpBinding does not require HTTPS. You can use HTTP if you set the SecurityMode to Message or None. However, since you are proposing to send a username and password with the service calls you definately shouldn't do that. If you do then anyone will be able to look at the message in transit and read the username and password and your security is totally compromised. I'm afraid you will have to get a certificate and use HTTPS. It's not so bad though and there are lots of resources on the web to help you.
By the way, you can do HTTPS with basicHttpBinding aswell as wsHttpBinding. Also, you should consider using REST for simplicity. WCF has good support for it (webHttpBinding) and better support coming with the Web API.
In answer to your second questions, you do not need the callers to be Windows users on your server and you can use a username and password. This is called Basic Authentication. Again, there is lots about it on the web. Start here.
If you do this you will obviously have to have a database to store usernames and password so you can validate then and grant or denay access to your service. The simplest way to achieve this with WCF is to use one of the default membership providers.

"Guarding" WCF service from certain users - application identity

We are using WCF services. Right now, we are using Windows Auth but this is not for long. Some services will sit outside the firewall and use username/password verified in the database.
My tech lead is "scared" at how easy any user can "Add Reference" to the services we have and just party on. He wants to "guard" the services by adding another identity - the application. He wants the service to accept requests from certain applications so the certain users cannot just use the service - add reference to it and call. It’s the notion of the application having an identity + credentials that is the operative principle here, as services on the network may need to authenticate those credentials prior to fulfilling a request, in order to prevent rogue code inside the network (i.e., NOT the application) from accessing services using “Joe User” end-user credentials.
Does this make any sense?
Then he believes the Juval Lowy's book has, in an Appendix that discusses sending more than one identity during a WCF call (Security Interceptor). There is no specific suggestion that all of those have to be end-user identities and if that is the case, one of those could be the identity of the application making the request.
How can this be done?
Thanks,
Sam
The problem with sending an application identity is that the secret used to confirm that identity has to be stored somewhere. If it is visible to one application on a machine then generally it will be visible to other applications running under the same identity.
Would your manager be happy with "it came from an authorised machine"? If that's the case you could simply use Client Certs
Its also worth taking a step back: if the user is authenticated and is authorized to perform the functionality they have requested, why do you care which application they came from - if they are who they say they are and they are allowed to do what they are requesting then why couldn't they use, say, fiddler to make the request - isn't that the point of a service (rather than a closely coupled client server app)?
You might want to look through Common Security Scenarios in the MSDN documentation to see if any of those options fit your needs.
The options that pops to my eye are Transport Security with Certificate Authentication and Message Security with Mutual Certificates. Both rely on X.509 certificates. The latter option is on the message level, so you can handle certificate delivery and security negotiation however you want.
To make it a lot harder for someone to add a reference to your service you could just remove the mex endpoint. This way it would be very difficult for a stranger to create a valid request message.
You can then distribute the WSDL manually, only to people you trust.

WCF Authentication -- Authenticate user/pass one time, then authenticate some other way afterwards?

Basically, I have the following scenario and information:
We're using HTTPS.
We want to authenticate a user by user/pass when they first log in.
After they are authenticated, I want any future calls to OTHER services (not the login service) to use the username and some sort of session (in case the password changes in the middle of a session).
I want to make sure my sessions can timeout and control them in a way that if a user tries to call a service and they don't have a session they get an error (cause they haven't logged in). Not sure if there's a WCF built-in way to do sessions this way or if I'll have to do something customized with a database.
I think we want to use WSHttpBinding (not BasicHttpBinding), 90% sure on this.
I just can't seem to figure out how to do this. Often time's I'll find information on the client code doing client.ClientCredentials.UserName.UserName = username and client.ClientCredentials.UserName.Password = password. But, that just doesn't work because what is my server checking against? I'm trying to grab that info and validate it against a database of user/passes. I'm not looking to use Windows Authentication or that sort (because I don't care who is logged into the computer, just who is logging into the app).
You want to use a Secure Token Service (STS) to authenticate and get a Security Token (maybe SAML) back that identifies the user which can then be passed to your other services and they can just use the identity information to identify and authorize because they trust the STS has verified the user's identity up front.
This is a large subject to discuss, so I suggest searching for WCF STS and doing some more research, but that's definitely the direction I'd recommend going. If you're going to build your own STS implementation, I also recommend looking into using the Windows Identity Foundation (WIF) components to ease your development efforts.
Here's the download link for WIF v1.0 which is the latest version at the time of this answer.

Authentication when using Security Token Service

I have created a Security Token Service (STS), an service with a reference to the STS and an example desktop application.
This works as expected when using Windows authentication and Message security, a token is retrieved from the STS and the service method is called successfully. The service returns a string containing the current users identity, which returns my AD username.
I have a requirement however to authenticate against a database rather than AD. I have tried creating a CustomUserNameValidator (in the STS, is this the correct place?) and referencing it in the web.config. I then provide the credentials as shown below.
SampleServiceReference.SampleServiceClient client = new SampleServiceReference.SampleServiceClient();
client.ClientCredentials.UserName.UserName
= "alex";
client.ClientCredentials.UserName.Password
= "pass";
I believe the certificates are set up correctly (all using 'localhost'), however I receive the following exception when calling the service:
System.ServiceModel.FaultException: ID3242: The security token could not be authenticated or authorized.
Whatever I try seems to fail. Is what I am describing even possible? Does the service client also pass the client credentials through to the STS, or am I completely misunderstanding what is happening here?
This stackoverflow question is similar, however I have checked the audience URL and it seems ok. WIF STS ID3242
Has anyone got any advice on how I can achieve custom authentication when using a STS?
Update: the code samples referenced below are not available anymore (Codeplex doesn't exist). The book download does and it is here: https://www.microsoft.com/en-us/download/details.aspx?id=28362
There's a simple example of what you need here: http://claimsid.codeplex.com
Look at either sample 8 or 4.
Small clarification though. The username/password authentication is on the STS, not on your service. Your service will authenticate with a security token obtained from the STS.
Have a look at StarterSTS.
The full source code is provided and it authenticates against the standard aspnetdb roles based SQL DB. There are a number of videos to help you get it up and running.
This project was then turned into ASP MVC - IdentityServer. This isn't quite as mature wrt the help files etc.

Easiest method to use a client-generated token for WCF authentication

(I tried searching, but couldn't find any truly helpful links.)
We are implementing a set of WCF services. What I would like to do in these services is have the clients (which will be trusted application servers) be able to pass a token of some sort to the web service to authenticate. I do not want to be required to pass username/password on the initial or subsequent requests (because in some cases the calling application server may not have the password). Windows and Kerberos are not usable in our specific circumstance.
I had thought to just create a simple custom UserNameSecurityTokenAuthenticator class and modify it so that if the password is empty, it takes userName as the string-encoded token value (obviously checking the token itself to verify that it's valid at that point), but if the password is not empty, forwarding on the username/password to a MembershipProvider for checking. Basically I'd like to overload the username/password authentication to provide for token passing as well.
Is this possible? Can I simply plug in a token authenticator like this, or is there some other simple way to "intercept" requests like this (and update the actual username value from the decrypted token)?
Or is there some other incredibly simple way to allow the client to pass a custom token and have the server accept it that I'm just missing?
If it's a fairly controlled environment and not too many clients involved, then I'd try to set up something along the lines of the B2B scenario securing the transport link using certificates on both ends.
Certificates are not bound to Windows or an AD domain, and setting them up is a one-time job.
Read more about that WCF security scenario:
MSDN: Transport Security with Certificate Authentication
Fundamentals of WCF Security: Business Partner Applications
. WCF Security How-To's