Adds authentication and access control utility methods.
Adds authentication and access control utility methods.

manuel-freire/a2,e-ucm/a2,e-ucm/a2,RotaruDan/test-users,manuel-freire/a2,RotaruDan/test-users,RotaruDan/test-users,manuel-freire/a2,e-ucm/a2