code: function _init() {
    // create padding
    _padding = String.fromCharCode(128);
    _padding += forge.util.fillString(String.fromCharCode(0x00), 64);
  
    // g values
    _g = [
      0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
      1, 6, 11, 0, 5, 10, 15, 4, 9, 14, 3, 8, 13, 2, 7, 12,
      5, 8, 11, 14, 1, 4, 7, 10, 13, 0, 3, 6, 9, 12, 15, 2,
      0, 7, 14, 5, 12, 3, 10, 1, 8, 15, 6, 13, 4, 11, 2, 9];
  
    // rounds table
    _r = [
      7, 12, 17, 22,  7, 12, 17, 22,  7, 12, 17, 22,  7, 12, 17, 22,
      5,  9, 14, 20,  5,  9, 14, 20,  5,  9, 14, 20,  5,  9, 14, 20,
      4, 11, 16, 23,  4, 11, 16, 23,  4, 11, 16, 23,  4, 11, 16, 23,
      6, 10, 15, 21,  6, 10, 15, 21,  6, 10, 15, 21,  6, 10, 15, 21];
  
    // get the result of abs(sin(i + 1)) as a 32-bit integer
    _k = new Array(64);
    for(var i = 0; i < 64; ++i) {
      _k[i] = Math.floor(Math.abs(Math.sin(i + 1)) * 0x100000000);
    }
  
    // now initialized
    _initialized = true;
  }
docs: Initializes the constant tables.