aa= function(a, b) {
for (var c = b.slice(32), d = [], e = 0; e < c.length; e++) {
var f = c.charCodeAt(e);
d[e] = f > 57 ? f - 87 : f - 48
}
c = 36 * d[0] + d[1];
var g = Math.round(a) + c;
b = b.slice(0, 32);
var h, i = [[], [], [], [], []], j = {}, k = 0;
e = 0;
for (var l = b.length; l > e; e++)
h = b.charAt(e),
j[h] || (j[h] = 1,
i[k].push(h),
k++,
k = 5 == k ? 0 : k);
for (var m, n = g, o = 4, p = "", q = [1, 2, 5, 10, 50]; n > 0; )
n - q[o] >= 0 ? (m = parseInt(Math.random() * i[o].length, 10),
p += i[o][m],
n -= q[o]) : (i.splice(o, 1),
q.splice(o, 1),
o -= 1);
return p
}

极验验证码-userresponse.js