I am trying to use nginx as a reverse proxy to web logic with two way SSL/mutual SSL.
Client <= Two way SSL => NGINX <= Two Way SSL => WebLogic server
proxy_ssl_trusted_certificate is used to verify the certificate of the upstream server, not to specify the client certificate which should be used when connecting to the upstream server. As far as I know there is currently now way to make ngnix use a client certificate in the upstream connection.
I have added support for two way/mutual authentication using certificate and key.
See the pull request:
https://github.com/nginx/nginx/pull/7
http://mailman.nginx.org/pipermail/nginx-devel/2014-August/005817.html
It is been validated against WebLogic 11g server which is configured for two way SSL.