Here is WCF binding and security question I'm quite confused:
You are hosting a Windows Communication Foundation (WCF) service at
http://www.contoso.com for a law enforcement agency. The agency adds
operations to support sending biometric fingerprint data via
non-buffered streaming. The service data is routed between
intermediaries. The WCF binding you are using by default does not
support encryption. You need to ensure that the fingerprint data is
not disclosed when passed over the network. What should you do?
A. Use basicHttpBinding with message security to https:// www.contoso.com
B. Use basicHttpBinding with transport security to https:// www.contoso.com
C. Use wsHttpBinding with message security to https:// www.contoso.com
D. Use wsHttpBinding with transport security to http:// www.contoso.com
Answer is B. But I think here it says "The service data is routed between intermediaries", so message security should be favour over transport security. Well, it did say "The WCF binding you are using by default does not support encryption", but the options here do offer using wsHttpBinding, so I think both A and C will do. Can anyone tell what I'm wrong there?
This sentence in the question is the key:
The WCF binding you are using by default does not support encryption
So that means the question is implying you are using basicHttpBinding, since wsHttpBinding has WS*-Security enabled by default. You can actually inspect the calls via Fiddler. The messages are signed and encrypted using a security token by default - for the gory details - this explains the SPNEGO token that is cached on the service.
So that eliminates C, D because of the sentence I highlighted earlier.
That leaves A and B. I don't agree with B as MSDN itself states that Transport security only secures messages with the communication is point to point. If the message is routed to one or more SOAP intermediaries before reaching the ultimate receiver, the message itself is not protected once an intermediary reads it from the wire.
The question also clearly says:
The service data is routed between intermediaries
Therefore, I beleive the correct answer is A, some WCF experts on SO may correct me.
Related
I'm new to WCF and IIS.
Suppose I set up a WCF service with wsHttpBinding and Message Security and Windows authentication. Does that mean I don't need to use https on my IIS server? Ie. Is the message secure or isn't it?
Let me know if there is any further information I can provide.
Yes, the message is secure as it will be encrypted and signed by WCF in case of Message security. But make sure you considered all disadvantages of massage security. The most significant are: 1. Poor interoperability. 2. Worse performance compared to transport security.
For more details please refer to this article Message and Transport Security
You will also find the scenarios where it is best to use message security.
start with transport and message security understanding. We will then see simple code samples of how to implement transport and message security using WsHTTP bindings. We will also see the differences between ‘BasicHttpBinding’ and ‘WsHttpBinding’ with the help of a simple code. WCF security is a huge topic by itself, but I am sure with this article you will get a quick start of how to go about WCF security
http://www.codeproject.com/Articles/36732/WCF-FAQ-Part-3-10-security-related-FAQ
Here on MSDN as well as here states the when dealing with wsHttpBinding, Transport security is handled via SSL.
On the MSDN page about SSL and WCF it states that when a ServiceHost is hosted within IIS, the ServiceHost leaves the SSL to be handled by IIS.
Would this not imply that if binding/securityMode="Transport", that any wsHttpBinding/binding/security/transport/clientCredentialType values would be ignored as none of their options are needed to set up the SSL transport?
It even appears to to say something to this effect here when it states
"When setting the security mode to TransportWithMessageCredential, the
transport determines the actual mechanism that provides the
transport-level security. For example, the HTTP protocol uses Secure
Sockets Layer (SSL) over HTTP (HTTPS). Therefore, setting the
ClientCredentialType property of any transport security object (such
as HttpTransportSecurity) is ignored. In other words, you can only set
the ClientCredentialType of the message security object (for the
WSHttpBinding binding, the NonDualMessageSecurityOverHttp object)."
And yet here for basicHttpBinding and for wsHttpBinding, they both categorically emphasis with examples that if security mode is set to Transport, set the binding/transport/clientCredentialType to something (eg: Windows).
What's the exact difference between Transport and TransportWithMessageCredential?
And do I have the wrong end of the stick, and the SecurityType enum (None|Message|Transport|Mixed) is not just for privacy, but for authentication to the server?
If Transport security is provided by SSL encryption, how did Authentication/Authorization get tangled into this stage?
Thanks immensely for helping me get a better picture of how this all fits together.
As far as I know the TransportWithMessageCredential is kind of "best of both worlds". The channel is secured on the transport layer so there is a secure connection between client and service (which can be very fast, implemented in hardware), plus the message is signed with message credentials so it can survive multiple hops before arriving at the service (validated in WCF).
And of course, you can use message credentials which are not supported on the transport layer, username/password for example.
I have an IIS-hosted WCF service which is configured to use basicHttpBinding with transport security.
I have configured IIS with a certificate and I'm using an https endpoint to call the service.
Now, I have enabled message logging on the service at transport level - however, the messages I'm seeing are in clear text. Is this right? If so, why? Is there a way to see the encrypted messages?
Thank you in advance,
Fabio
This is correct behavior. Transport layer handles its decryption before it passes message to upper layer api like WCF so WCF always get message decrypted and it can't intercept the process - transport security is outside of WCF. Encrypted message on transport layer is logged only if you use message security because in such case transport layer just passes the message as is to WCF to deal with it.
Use Fiddler and don't enable SSL decryption in the options. It will allow you to inspect the message traffic as it is on the wire.
Also, worth reading is Debugging Localhost Traffic with Fiddler, a common gotcha for those new to Fiddler. Then check out the info page on HTTPS decryption, if you're interested in using that feature later.
What is the strength of the default TCP transport security using WCF netTCPBinding? Is it HIPAA compliant and where is documentation stating this?
HIPAA compliance only says what, not how. HIPAA requires you to prevent the data from being read in transit. It must be encrypted in some way that makes it non-trivial to decrypt.
From the HHS web site (http://www.hhs.gov/ocr/privacy/hipaa/understanding/srsummary.html):
Transmission Security. A covered
entity must implement technical
security measures that guard against
unauthorized access to e-PHI that is
being transmitted over an electronic
network.
The safest bet is to use the maximum security that the netTCP binding offers, which is SSL over TCP and message authentication:
NetTcpBinding binding = new NetTcpBinding();
binding.Security.Mode = SecurityMode.TransportWithMessageCredential;
You'll want to review the guidance on MSDN about Transport and Message security. There are also many great posts here on SO about configuring security with the netTCP binding.
Be sure to check with your legal department on your company's particular rules on transmitting e-PHI.
To answer your question, when configured correctly, the netTCP binding can securely encrypt traffic, which can meet the Transmission Security requirement.
netTCPBinding is an appropriate system-provided choice for communicating over an Intranet. The default configuration for the NetTcpBinding is faster than the configuration provided by the Htpp bindings.
On another note, I am not sure whether it is HIPAA compliant or not.
I'm creating a simple web service using WCF. The message needs to be encrypted and the user need to be authenticated through an asp.net provider.
What binding should I use for this? WsHttpBinding or WebHttpBinding?
Can anybody point me to a good example using the asp.net provider and self signed certificates with wcf.
Thanks
You say that the message needs to be encrypted, but don't specify whether you have a specific requirement for message-level encryption or if transport encryption might be enough.
If you transport-level encryption is enough, then BasicHttpBinding + SSL would work.
Otherwise, you'd use WSHttpBinding and configure message-level encryption. Of course, the decision might also be tied to the capabilities of any clients you want to consume the service.
You also mention WebHttpBinding, but that's used only for REST-style services. Is your service REST style? If so, then your only option would be SSL and using transport-level authentication, I think.