This article will assist you with the setup of an external Enterprise portal site using Auth0 user authentication mechanism.
Start by downloading the required KB
4133646 for Dynamics AX2012 R3. Also required is a bug fix in KB
4462353.
Secondly, download the PDF file
Dynamics-AX-2012-R3-Enterprise-Portal-Setup-with-Auth0. This document will describe all the steps required to setup your external Enterprise portal site using Auth0.
NOTE: When setting up Auth0 providers such as LinkedIn or Yahoo, make sure to select the attribute for the connection to include email address, as that is a required field for this solution to work.