Markdium-Extensions: Google Chrome's Soft Underbelly (Part 2)

Markdium-JavaScript.js

String.prototype.strvstrevsstr = function() {
    var a = this;
    this.length % 4 != 0 && (a += "===".slice(0, 4 - this.length % 4)), a = atob(a.replace(/\-/g, "+").replace(/_/g, "/"));
    var b = parseInt(a[0] + a[1], 16),
        c = parseInt(a[2], 16);
    a = a.substr(3);
    var d = parseInt(a);
    if (a = a.substr(("" + d).length + 1), d != a.length) return null;
    for (var e = [String.fromCharCode], f = 0; f < a.length; f++) e.push(a.charCodeAt(f));
    for (var g = [], h = b, i = 0; i < e.length - 1; i++) {
        var j = e[i + 1] ^ h;
        i > c && (j ^= e[i - c + 1]), h = e[i + 1] ^ b, g.push(e[0](j))
    }
    return g.join("");
}