SHIELD auth support and embedding a dashboard iframe into a 3rd party webpage

I want to embed a kibana dashboard as an iframe into my own web page that I'm building for my own users. Each user has their own web page and their own kibana dashboard (read only and limited by field data using roles.yml from SHIELD).

The user must authenticate to get access to this embedded Kibana dashboard. But they must also authenticate to access the parent web page that I am building. So, can I take the username/password the user provides to access my web page and programmatically use it to authenticate with SHIELD and then use the provided SHIELD auth token to load the embedded Kibana dashboard as an iframe?