Refer to this Code base to Implement your Own Authentication Server
https://github.com/HexaEightTeam/BuildUROwnAuthServer
Once the Authentication is implemented, Cookies are available for your own domain.
Use these cookies to identify the users in any of your domain application.
Visit Our Website to Learn more about our Session or Token based Authentication
To Learn More about Our Authentication Server visit www.hexaeight.com
More Code Samples are available at here