Why will a 2 dimensional one not work?
http://www.shapeways.com/blog/archives/654-tutorial-how-to-create-your-own-ring-in-blender.html is targeted at creating products for shapeways, however the same principle will work with a generated black and white maze.
A quick google turns up this site http://www.billsgames.com/mazegenerator/ which i have used before. Combining these two things should create editable mazes.
Best of luck,