I have no idea if this will work, but maybe you can figure something out. Authentication Manager has Web Agents for IIS and Apache, so maybe trying Apache is worth a try if NginX Web Server looks or behaves like Apache. Even if you got it to work it would not be supported, which means any bugs you find would have to be reproduced on a supported platform.
The next thing to look at might be how does the NginX Web server authenticate users? If it allowed authentication to a RADIUS server, that would work with Auth Manager.
But if neither of the above approaches pans out, and I would not spend a lot of time testing, then the last option would be to write your own agent using the RSA Authentication agent API SDK, comes in C or Java. The 8.1 version uses the classic API to the UDP 5500 port on the AM server, works great, been around a long time, but no IPv6 support. The 8.6 agent API (skip the 8.5 version) talks to the TCP 5500 port on the AM server, basically using a Cert from the Server to build an SSL connection for authentication, and supports IPv6. Either way the agent API allows more flexibility and control, you just have to know how to code and solve problems on your own, as a standard support contract only gets you sample code so you can see an authentication from your platform.
