05 Browser gimmicks

For some mysteries it pays to have gathered some knowledge around the internet, browsers and scripts.

When searching for the coordinate, it is often useful to have a look at the source code of the geocache listing and to roughly understand what is typical content here and what might belong to the puzzle. Paying attention to the file names (e.g. of embedded images, the background image) or the place where they were stored on the internet can also be a clue or even the solution. And sometimes a mystery owner creates his own website and then has quite a few possibilities to block the puzzler’s way to the solution. I’ll try to explain some of them here.

Your internet browser reveals a lot of information to an interested web server. This is not due to any surveillance mania, but simply due to the technology with which a web server presents the web pages to the browser and these are displayed to the user.

A small overview of what is revealed can be obtained, for example, here:

  • http://www.hashemian.com/whoami/

Proxies and IP ranges

The internet provider, e.g. Telekom or Vodafone, assigns – in simplified terms – a unique number to each user, the IP address. Depending on the type of Internet access, it is always the same or changes, then usually daily. IP addresses consist of four number ranges from 1 to 255, separated by dots (e.g.: A distinction is made between private and public addresses, i.e. those that you may have at home in your own network (if you want to connect several computers with each other) and those that your provider gives you for surfing the Internet. There is a worldwide registry for public addresses and something like “address books” where you can look up for each address to which provider, as to which country it belongs. In this way, Youtube can (must!) ensure, for example, that songs that are not malicensored in Germany are not played by computers with German IP addresses. Instead of the songs, there is always this sad “It’s GEMA’s fault” Youtube picture.

Technically savvy mystery owners can do the same thing, i.e. check from which country someone is surfing the website and, in order to increase the mystery difficulty, block out German surfers, for example. But no one has to travel abroad just to solve such a mystery. It is enough to use a proxy. A proxy is a kind of intermediary through which you call up the page in question. This then only sees the IP address of the proxy and no longer that of you.

This works if you find a working proxy server (google spits out various sites that offer proxy lists) and enter it in the network settings. With Windows 8 and 10, it is sufficient to enter network proxy in the tile interface and you will land in the appropriate menu. For Windows 7, start > Control Panel and then select “Internet Options” in the category “Network and Internet”, for Windows XP, start > Settings > Control Panel > Internet Options. For other operating systems, I don’t know off the top of my head right now.

Firefox and Chrome users can also use add-ons for this purpose, with which the proxies can be conveniently switched on and off via the browser menu. Some also offer proxy lists for selection. However, I will not be able to give a recommendation here (just as little as with the proxy lists), because the selection is extremely opaque and changes frequently.

Surfing via proxies is also not really nice, usually they are very slow, if they work at all. The only thing that helps is to try them out several times. But what won’t you do for a nice puzzle? 😉

By the way, the owner of the proxy server can read and record your web traffic. Keep this in mind when surfing through a proxy and entering login details, for example!

HTTP headers – user agent, referer and accept language

This spat out – among other things – one of the above pages about me and my browser.

HTTP_USER_AGENT: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:42.0) Gecko/20100101
HTTP_ACCEPT: text/html,application/xhtml+xml,application/xml;q=0. 9,*/*;q=0.8
HTTP_ACCEPT_LANGUAGE: de-DE,de;q=0.8,en;
HTTP_REFERER: https://www.google.de

The web server on which this page is located therefore knows which browser (user agent) I am surfing with, which language I speak and which website I came from (referer). These typical HTTP header values can be changed, again most easily via corresponding add-ons for Firefox and Chrome.

And for those who think this is too weird, I’ve had several mysteries where I had to set fantasy languages as accept languages and specify non-existent browsers as user agents. Or I had to forbid websites from setting cookies (there are also add-ons against this, but you can also activate them in your own browser settings). And several mysteries required me to deactivate Javascript to solve them. Since I surf with a script blocker anyway, this only required one click for me. Theoretically. Practically, I first had to get the idea that the owner was asking me to do just that.

Just like the mysteries where there is an ominous URL or string that starts with www.xn--. These are web addresses that are not written in Unicode (i.e. with internationally defined standard characters), but contain special letters, e.g. Ä, Ü and Ö , which contain French, Swedish or even Chinese “special characters” (see Wikipedia). To be able to display them on any browser, these web addresses are converted and displayed in the format with “xn--” at the beginning. Thankfully, the internet provides us with converters that allow us to reverse this and read them.

From time to time, I use the Firefox add-on Firebug (there is something similar for other web browsers) for detailed examination of concerning web pages. Actually made for debugging web page programming, it can be used to examine all elements of a web page in a better way and for one or two mysteries I actually had to change parts of the HTML code this way to reach the goal. But explaining that here would go too far (and probably spoil too much?), so I’ll leave it to you to delve deeper into this matter in the appropriate case.