Security and Authentication Settings|OPC UA Implementation: Stacks, Tools, and Samples|Forum|OPC Foundation

I am pretty new on OPC UA. What I did is grab the latest copy of the OPC UA Stack on Github and develop an OPC UA Server on top of it. Basically, i reused the Data Access Server application. Now i would like to try to exchange certificate with any OPC UA Client and i dont know how this thing work.

Currently I am using UaExpert as my OPC UA Client. I have tried to change the security settings (Security Policy and Message Security Mode) and when I connect i get a message "The connection cannot be established, because the server does not support the configured security policy". I wonder how I can configure my OPC UA Server which is developed on top of the OPC UA Sack to support such configuration.

For Security Settings, I am able to connect as long as i am using None. Using combination of Basic256, Basic128Rsa15, Basic256Sha256, Sign and Sign & Encrypt gives me the above error message.

For Authentication Settings, I am able to connect as long as i used Anonymous. How to configure the OPC UA Server to use Username Password or Certificates?