I have configured SSL Client Authentication with the "Require a client certificate" option in Stingray.
Now I'd like to give a user a nice error message if the user does not represent a valid certificate. Can I somehow configure a customized HTML error message for this situation?
In general, it's not possible to do this.
The protocol for requesting and validating a certificate is defined by the SSL protocol; it works as follows:
I don’t believe there is an opportunity to send a redirect to a helpful error page when the handshake fails.
One option that may work for you:
The web browser will display the page of instructions and commence the process of asking the user for his certificate.
Hope that this helps