function to generate auth token from URL for goo.gl

getGooglAuthToken.js

var getGooglAuthToken = function(b){
	var c = function(){
		for (var l=0, m=0, ml=arguments.length; m<ml; m++) l = l + arguments[m] & 4294967295;
		return l;
	}
	var d = function(l){
		l = String(l > 0 ? l : l + 4294967296);
		var m = l;
		for (var o=0, n=false, p=m.length-1; p>=0; --p){
			var q = Number(m.charAt(p));
			if (n){
				q *= 2;
				o += Math.floor(q/10) + q % 10;
			} else o += q;
			n = !n;
		}
		m = o % 10;
		o = 0;
		if (m != 0){
			o = 10 - m;
			if (l.length % 2 == 1){
				if (o % 2 == 1) o += 9;
				o /= 2;
			}
		}
		m = o + l;
		return m;
	}
	var e = function(l){
		for (var m=5381, o=0, ll=l.length; o<ll; o++) m = c(m << 5, m, l.charCodeAt(o));
		return m;
	}
	var f = function(l){
		for (var m=0, o=0, ll=l.length; o<ll; o++) m = c(l.charCodeAt(o), m << 6, m << 16, -m);
		return m
	}
	var i = e(b);
	i = i >> 2 & 1073741823;
	i = i >> 4 & 67108800 | i & 63;
	i = i >> 4 & 4193280 | i & 1023;
	i = i >> 4 & 245760 | i & 16383;
	h = f(b);
	var k = (i >> 2 & 15) << 4 | h & 15;
	k |= (i >> 6 & 15) << 12 | (h >> 8 & 15) << 8;
	k |= (i >> 10 & 15) << 20 | (h >> 16 & 15) << 16;
	k |= (i >> 14 & 15) << 28 | (h >> 24 & 15) << 24;
	return '7' + d(k);
}