handling square might not be trivial, and are probably mostly important for pedestrian routing. so this might be for a future version.

the thing with a square is that you can cross it in any way. unfortunately squares can have odd shapes, so it's not always possible go in a straight line from where you enter to where you leave. for example a building might be in the way if the square has a hour-glass shape.

a simple example is "Prins Jørgens Gård" is a square, tagged with highway=pedestrian, area=yes:
http://www.openstreetmap.org/?lat=55.676763&lon=12.579427&zoom=18&layers=M

if i set up a pedestrain speedprofile, which includes 'pedestrian=5', osrm will route at the edge of the square. this is will get me across the square, but in a somewhat odd fashion.

one option would be to add routes connecting all entries to the square to all others. another would be to connect all entries to a central point. perhaps these to options could be improved by checking that routes are only added if they don't cross the square boundary.

a third option would be be still route along the edge of the square, but insert the route some reasonably distance from the edge, since in reality you cant walk right at the edge of the building.