Rotating a matrix

Suppose you are given matrix M, with dimensions N by N. Write a function that rotates the matrix M by 90 degrees in either direction (clockwise or counterclockwise).

For example, if you're given the following matrix:

 [[4, 6, 7], 
  [2, 3, 8],
  [9, 10, 23]]

Your function should return the following if you're rotating clockwise:

 [[9, 2, 4],
  [10, 3, 6],
  [23, 8, 7]]

...and if you're rotating counterclockwise, it should return:

 [[7, 8, 23], 
  [6, 3, 10],
  [4, 2, 9]]