Linux Authentication with Windows 2012R2 Server (Deprecated IMU role)
Solution 1:
I believe FreeIPA was built from the ground up to connect UNIX/Linux with AD DC (Microsoft) and authenticate users.
Link to FreeIPA
"Create mutual trust with other Identity Management systems like Microsoft Active Directory."
Good luck! :)
Solution 2:
I ended up going with Pass Through Authentication over OpenLDAP and SASL. FreeIPA looks good though.