C# in VS2010, using WCF, Hierachical Certificates and IIS6

Question

Hi guys,

We've been working a lot in an application developed in VS 2010, C#, and WCF. We use Transport as the security mode, and in the TransportSecurity Properties set to None and None.

We are hosting the service in IIS6. After working a lot we managed to make it work using https. The Certificate we used was a self created one, created with the selfssl.exe tool. After creating the Certificate and storing it in the "Trusted Certificates" list, we set it as the Server Certificate in IIS for our Site, and also do the "binding" between the Certificate Thumbprint and the localhost address with the 443 port, using the httpcfg tool.

Well, we also use the famous piece of code not recommended for production (we are aware of that) that enables the validation of a Certificate that is not issued by a valid Certification Authority. This piece of code we took it from the MSDN WCF Hands On Lab. In this piece of code we give it the CN=NAME of the certificate and it works.

Ok, we finally got it to work. This was all in development. Now we are in the testing stage and they agreed to use the piece of code that enables the certificate. The problem is that the Certificate that we need to use, after setting it in the IIS and setting it to use the famous piece of code, it doesn't work.

The error we get is this one (only showing the first part of the error and not the stack trace):

System.ServiceModel.Security.SecurityNegotiationException: Could not establish trust relationship for the SSL/TLS secure channel with authority '172.30.224.46'. ---> System.Net.WebException: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel. ---> System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.

The new Certificate is issued by their own Certification Authority, and it has several differences in comparison with our Self-Generated one, for example the "Usage" properties are different, or for example our Certificate has a "Enhanced Usage" property and theirs don't.

The other great difference we notice in the Certificate is that theirs is part of a hierarchy of Certificates, where they have a Trusted Root Certificate, then an Intermediate Certification Authoity and the Certificate to use in the Server is under that Intermediate one.

Is a special configuration needed to support this kind of certificates that are part of a hierachy? What can you guys tell us about this? .... we need some help :S

We also made a test creating a Self-Signed Certificate and all the steps needed to set it up in their environment, and the application works.

Thanks for your help and attention,

Andrey Gonzalez

Answer 1

Usually you get this error when the server name stored in the certificate is different from the hostname you use on the client to refer to the server.

For example, your server certificate is issued for "yourserver.com" and you are trying to access it from the client using only "yourserver" or its IP address.