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Sheogorath's Blog


Depending on the time of the day a friend, a colleague, a wise guy. The beauty of the world is its sense of humor to show humans their way by letting them search their own.


  1. No ESNI in China

    Today I learned that China is blocking TLS 1.3 connections that use the new ESNI standard. ESNI stands for “Encrypted Server Name Indication” and is part of experimental TLS 1.3 features. Other TLS version such as 1.2 use SNI to identify what certificate a client requests. What this means is, even while the entire communication between the server and the client is encrypted, during the initial handshake, the client sends the expected server certificate name in cleartext. This allows Firewalls and other middle boxes to snoop on those names and detect suspicious domains. This is often used to block those connections. ESNI encrypts those names during the initial connections as well and this way prevents this snooping. This means, for the first time, the TLS connection itself doesn’t provide any useful Meta-information about the target of the connection. China doesn’t seem to like that as it would allow any host to easily proxy all kinds of connections with no way for the “Great Firewall” to apply their block lists except of IP addresses. …


  2. Jekyll, RSS and absolute URLs

    Today I learned that I did absolute URLs overly complicated. In this blog I use absolute URLs for almost all links in order to make things RSS standard compliant. In Jekyll this can be achieved in various way, and so far, I used a very explicit way looking like this: {{ site.url }}{{ site.baseurl }}/assets/images/2016/03/some-picture.png. But the same thing can be achieved so much easier but simply using {{ "/assets/images/2016/03/some-picture.png" | absolute_url }}. …


  3. Colour balancing

    Today I learned about the maths behind colour balancing. Colour balancing is the act of correcting all colours in the picture to represent their real colour based on a selected pixel within the picture which colour code is known. Usually this pixel is white, which is it’s also called white balancing. There are obviously multiple algorithms to do that, the simplest one, is a matrix multiplication. In images colours are usually represented by a vector of the 3 RGB-base colours (red, blue, green) and their intensity ranging from 0 (off) to 255 (maximum). When all base three colours are on 255 the result is white, when all of them are 0 the pixel is black. With that said, what happens now, is that the selected known white pixel is taken, it’s current picture represented colours are used to divide 255 as part of of a diagonal matrix. Afterwards the resulting diagonal matrix is taken to calculate the new value of each pixel by multiplying the matrix with the pixel’s vector representation, resulting in a new vector, representing the pixel. …


  4. Hugo provides an own web server

    Today I learned that the hugo server-command can run be used in production. According to the Hugo documentation it’s considered a valid use-case but you might want to disable the live reload feature. It sounds contra intuitive as Hugo itself is a static page generator and one would usually use it to generate a page and then let it be served by another webserver/CDN/…. …


  5. The UX of LEGO

    Today I learned that one can categorize and describe the usability of LEGO “computers” and use this for educational purposes. In the article I read today I organized all those LEGO “computer interfaces” into categories from all screen to no screen and from organized to chaos. Basically pointing out that some of those designs make little sense, while others are done rather well. The gist is, that a good interface is usually following the user’s flow, not the engineer’s and that switches with different purposes should be notably different from each other. It literally makes a difference of life and death in some situations. …


  6. Spam in Hawaii

    Today I learned that Spam plays a huge role in Hawaiian culture. Food culture. I was aware of the fact that Spam is actually a brand name for canned meat from the US, but I wasn’t aware that it was playing such an important role in Hawaiian food that they even have an own “Spam food festival” with all kinds of canned-food combinations that one wouldn’t expect. …


  7. Snyk disclosure handling

    Today I learned that one can report found vulnerabilities to the company “Snyk” which will take care of the responsible disclosure procedure. Means they will take the report, validate it, assign it a CVE, contact the maintainers and disclosing it to the public after 90 days. …


  8. Subtile sexism in marketing

    Today I learned about a very subtitle but very present form of sexism that is hiding in plain sight and where I truly believe that no one does it intentional. Sports ads. It was a child that pointed it out and her mother posted about it on Twitter. The child noticed that while all boys on the ads were involved in some sports activity like playing football or doing kick boxing etc. while the girls were only posing like adjusting their hand wraps or stretching. …


  9. Wendepailletten

    Today I learned that so called “Wendepailletten” (turn-around-sequins) exist. Sequins themselves are nothing new obviously little metal or plastic plates that are put on cloth to decorate it or become cloth. But those “Wendepailletten” go one step further. While being popular amount kids, the concept itself is rather interesting. The sequins are put on the cloth using a specific embroidery technique to allow them to be turned upside-down. By taking sequins with different back and front colour, it’s possible to create pictures that can be change in parts or entirely by swiping across them. It’s super simple and still amazing. …


  10. Rabbits, grass and eating habits

    Today I learned that rabbits, as well as cows, don’t digest grass directly. While cows use their stomachs to get the grass eaten up by bacteria that is afterwards digested by the cow itself, rabbits don’t have the luxury of many stomachs. Instead they produce a special kind of faeces after eating the grass for the first time, that allows them to digest it at the second time, after eating those faeces. This process is called coprophagy. …