There is a server with WCF client, which periodically initiates communications over internet with many WCF services installed on our clients computers. WCF services and WCF clients are hosted in Windows Service, current binding is basicHttpBinding.
Communication has to be over https with mutual authentication. Company ordered SSL certificate but it is not clear if this certificate can be installed on clients computers (because WCF service is there) without exposing a private key. Binding can be basicHttpBinding or wcHttpBinding with transport or message security but using certificates.
Is it possible to install service-side certificate on client computers and client-side certificate on our server? Should this architecture be re-worked so WCF service is on our server or it is possible to secure somehow this current solution?
Each computer involved requires it's own certificate. A certificate value for authentication relies on the uniqueness of the private key. The private key never leaves the host machine, and the certificate can be used to authenticate said machine (because is the only one in the world that posses that private key). As soon as you start distributing copies of a private key, security is pretty much compromised.
Normally such deployment rely on PKI infrastructure which can create certificates on-demand and sign them with a trusted key.
What product/protocol the certificates are used for is irrelevant. What kind of WCF HTTP binding you use it maters not.
Related
I realize the number of question about SSL certificates is legion, but after much searching I couldn't find a precise answer to the following confusion.
For one-way SSL, under what circumstances does the consumer of an HTTPS web service need to import the provider of said web service's certificate/public key? I've consumed a few web services over https before and never had to add the other company's certificate or public key to the key store (or is it trust store?) of any device at my company.
And yet apparently sometimes that is the case, as evidenced by these examples:
certificate mechanism between webservice provider and consumer
Consuming RESTful service over https with certificate using Java
Is it only necessary when the provider of the service's certificate is not issued by a CA known to the consumer?
Also, if the consumer does end up having to import the provider's certificate, AND it's the case that the consumer's consuming app itself consists of a client part and a server part, does the consumer import it into the store of the consumer's web server or into the store of each and every client computer at the consumer's company?
Finally, for two-way SSL, does the consumer send his own client certificate with code that executes on his (possibly many) client computers or on his own web server?
Thanks for any clarification.
Is it only necessary when the provider of the service's certificate is not issued by a CA known to the consumer?
yes. When relying party uses certificates from a globally trusted CA, there are no extra actions required to install foreign certificates.
into the store of each and every client computer at the consumer's company?
if issuer is not globally trusted, it must be installed on every device that consumes service with custom certificate.
does the consumer send his own client certificate with code that executes on his (possibly many) client computers or on his own web server?
it's unclear what do you mean. Can you elaborate?
update:
It depends on how 3rd party server authenticates you. Are they ok to identify your app as whole or they require to distinguish every internal user. In first case, it is enough to have single client certificate within your app and you will have two separate TLS connections:
3rd party server <--TLS--> Your App <--TLS--> End user (many)
End users connect and authenticate only on your application. When necessary, your app establishes a separate TLS connection to 3rd party and work is done. It is quite common practice. End users are not aware of 3rd party server and 3rd party server is not aware about your internal users (and probably should not be).
One of my teammate just enabled SSL on one of the service that we are using and I had to install a Certificate that he gave me to each of the client machines who intend to consume that service. Now, I am not very well-versed when it comes to SSL security and that raised a question in my mind that
WHENEVER we create a SSl enabled service, do we have to hand out certificate to all the clients
Is there any kind of configuration using which we create an SSL enabled service without having to hand out certificate to all the clients?
IF it is possible then how secured that service be than the service which requires each client to install certificate on the machine?
Also, is there any easy to understand article on WCF SSL security?
Que : WHENEVER we create a SSl enabled service, do we have to hand out certificate to all the clients
Ans : No. For SSL enabled service one do not need to handout certificates to clients.
SSL certificate on server (in this case service) side gives confidence to clients that they are talking to legitimate server.
Clients needs certificates only in case of when service needs its clients to prove their identity using client certificate. With client certificate server (service) gets confidence that its sending data to legitimate clients.
Que : Is there any kind of configuration using which we create an SSL enabled service without having to hand out certificate to all the clients?
Ans : Certainly there is way with which you can make service enabled without requiring client certificate. Check SSL Settings option for website where service is hosted.
Que: IF it is possible then how secured that service be than the service which requires each client to install certificate on the machine?
Ans : Obliviously using SSL certificate doesn't stop any clients from consuming it. Any client who knows service endpoint can consume it. Client certificate is one way to authenticate clients. Only those clients who has valid client certificate will be able to consume service.
Que: Also, is there any easy to understand article on WCF SSL security?
Ans : Check out this link : https://msdn.microsoft.com/en-us/library/ff650862.aspx Its WCF regarding security as whole and not just SSL security.
What's the easiest security mode for implementation in WCF when:
Both client and service are .NET applications.
Client and service are negotiating over internet.
SSL in not available.
Port 80 (web) is preferred for communication.
And Using a x 509 certificate should be the last option (same credentials in configuration file at both sides is preferred, if possible)
Security means a lot of things:
Authentication
Authorization
Confidentiality
Integrity
To name a few. You need to decide what are your requirements for each.
Since SSL is not available you must use message level security. But assuming machines do not necessarily live on the same windows domain you cannot use windows authentication and must use x.509 certificate, at least on the serve side. So:
<customBinding authenticationMode="usernameForCertificate" />
where the client authenticates with a username and the server with a certificate (client need to install this certificate).
You could also use a WSHttpBinding with all default settings except:
messageClientCredentialType=UserName
In which case client does not need to install the certificate, it gets it automatically in runtime via negotiation.
Both client and service are .NET applications.
Take a look here http://msdn.microsoft.com/en-us/library/ee707353(v=vs.91).aspx
We have selfhosted WCF services running using NetTCP:Transport:WindowsClientCredentialType
// Set Binding Security.
netTcpBinding.Security.Mode = SecurityMode.Transport;
netTcpBinding.Security.Transport.ClientCredentialType = TcpClientCredentialType.Windows;
netTcpBinding.Security.Transport.ProtectionLevel = System.Net.Security.ProtectionLevel.EncryptAndSign;
We now need to expose these services to domains outside our own but want to continue selfhosting and not use IIS. Thus I am trying to switch us to a ClientCredentialType of Certificate.
// Set Binding Security.
netTcpBinding.Security.Mode = SecurityMode.Transport;
netTcpBinding.Security.Transport.ClientCredentialType = TcpClientCredentialType.Certificate;
netTcpBinding.Security.Transport.ProtectionLevel = System.Net.Security.ProtectionLevel.EncryptAndSign;
I have previously setup a development environment (long ago) where we used MakeCert to generate a "dummy" certificate for development purposes with WCF. But we have since purchased a certificate from Verisign. I am a bit fuzzy on what needs to happen now. I can see us using this certificate to validate our Services to the Client, but how do we validate our .NET client with certificate? Do we use the same certificate? Do we have to install this certificate during install of our client? Bit wrapped around the axle here and could use a could explaining if anyone can help out.
No you will not install your certificate with private key on your clients. You mustn't give your private key to anybody - once it is compromised your security has gone! The problem is that client certificate must have a private key as well but that private key must be owned only by that single client. That means another certificate per client.
How is it usually implemented? By local certificate authority issuing certificates to your clients. Your service will trust that authority and so all clients holding certificates issued by your authority. That is the only scenario to get this under control otherwise you need to find another mechanism to authenticate your clients.
I have two WCF Services using WsHttpBinding with transport security mutual certificate authentication that are being hosted on the same windows server. Clients that can access one WCF service should not have access to the other WCF service. I need some help on configuring the client certificates on the windows host. The client certificates are signed by trusted CAs and the intermediate and root certificate chain is already installed on the the server. It seems like the service automatically relies on chain of trust and does not require the actual client certificates installed on the server at all before letting the client access the service - this is not the behavior I want. Can someone please tell me how I should be configuring these client certificates in order explicitly allow access to one service and not the other?
Thanks.
That has nothing to do with certificates themselves. When using mutual SSL authentication certificates are used only to authenticate client and the authentication is done outside of your application (this is difference to message security where you can create custom certificate validator). Once certificate is trusted client is automatically authenticated to anything on the server using certificates for authentication.
You are looking for authorization - the step where you define what can authenticated client do with your service. You can either hardcode your authorization logic into your service by using role based security or you can implement two custom ServiceAuthorizationManagers and assign each to single service.