security.js

var assert = require('assert');
var crypto = require('crypto');

var EXTERN_APEX = 0xFBEE9;
var ucs2_control = 'a\u0000';
while (ucs2_control.length <= EXTERN_APEX) {
  ucs2_control += ucs2_control;
}

var b1 = new Buffer(ucs2_control, 'ucs2').slice(900000);
var b2 = new Buffer(ucs2_control, 'ucs2').slice(900000);

// #### mutating b2 above the blind spot ####

var i = b2.length;
function mutate() {
  i -= 1000;
  if (i < 0) return;
  b2[i] = 255 - b2[i];

  var hash1_converted2 = crypto.createHash('sha1')
    .update(b1.toString('base64'), 'base64')
    .digest('hex');

  var hash2_converted2 = crypto.createHash('sha1')
    .update(b2.toString('base64'), 'base64')
    .digest('hex');

  console.log("%d - %s vs %s", i, hash1_converted2, hash2_converted2);
  if (hash1_converted2 != hash2_converted2) {
    console.error('should not have hashed the same while different above the index ' + i);
    i = -1;
  }
  setImmediate(mutate);
}
setImmediate(mutate);