Randomize an Array

stir

var crypto = require('crypto');

var hash = 'SHA512';

function getStirHash(key, blocknum, length) {
  var stirhasher = crypto.createHash(hash);
  stirhasher.update(key);
  stirhasher.update(blocknum.toString().toString('binary'));
  stirhasher.update(length.toString().toString('binary'));
  return new Buffer(stirhasher.digest('binary'), 'binary');
}

function getStirMap(mapBuffer) {
  var currentByte = 0,
      currentBit = 0;

  return function (left, right) {
    var result = mapBuffer[currentByte] & (Math.pow(2, currentBit));
    currentBit += 1;
    if (currentBit >= 8) {
      currentBit = 0;
      currentByte += 1;

      if (currentByte >= mapBuffer.length) {
        currentByte = 0;
      }
    }
    return result ? 1 : -1;
  }
}

var stirhash = hashes.getStirHash(key256, 3, 2);
var stir = stirmap(stirhash);

toStir.sort(stir);