Question

I am using https to connect to an https server.
Specifically I am using apache httpclient and I configure the ssl context to use my keystore and truststore.
The https server I am using is IIS7 and is configured to require client authentication.
I think I have set it up properly.
Anyway, if I configure the httpClent’s ssl context with a keystore (i.e. with client certificates) valid for IIS then there is no problem connecting.

Now my problem is the following:
If I do not configure the ssl context with any client certificate to send to IIS, there is no connection with the server. What makes me think though, is the fact that I was expecting to see some java exception in the code as a result of a hanshake failure alert.
Monitoring what is happening with wireshark, I could not see a certificate request from IIS to my application, but I noticed that after ServerHelloDone everything was encrypted.
I did not expect that. I think the handshake is usually in cleartext.
I used private key to decrypt traces and i saw a certificate request from IIS but after many starting and opening of new connections.
My app send back as a response a certificate of length 0 and IIS replies with a TLSv1 Finished.
After that the packets stop (i.e. seems that the communication ends).
I was expecting a handshake alert.

My question is, is this how it is supposed to work or at least how IIS works?
Or if I do not see the alert something is wrong with my use case?

Thanks

Answer 1

As I was saying in an answer to this question, as far as I remember, IIS uses re-negotiation to get the client certificate. You should be able to change this behaviour using netsh and clientcertnegotiate=enable (depending on the version of IIS you’re using).

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