Hackad: curl use on TV

There’s this new TV-show on Swedish Television (SVT) called Hackad (“hacked” in English), which is about a team of white hat hackers showing the audience exactly how vulnerable lots of things, people and companies are and how they can be hacked using various means. In the show the hackers show how they hack into peoples accounts, their homes and their devices.

Generally this is done in a rather non-techy way as they mostly describe what they do in generic terms and not very specifically or with technical details. But in some short sequences the camera glances over a screen where source code or command lines are shown.

A little mr Robot like but in reality.

Similar to the fictional mr Robot, a readily available tool to use to accomplish what you want is of course… curl. In episode 4, we can easily spot curl command lines in several different shots.

Jesper Larsson is one of the hackers in the show and he responded on this blog post about them using curl, on Twitter:

Screenshots from episode 4

Lots of curl command lines
Markdown document with embedded curl command lines
Another snap of the same document showing more curl
David’s laptop when outside the house, showing a number of curl command lines, slightly blurry.

curl installations per capita

I’ve joked with friends and said that we should have a competition to see whom among us have the largest number of curl installations in their homes. This is of course somewhat based on that I claim that there are more than ten billion curl installations in the world. That’s more installations than humans. How many curl installations does an average person have?

Amusingly, someone also asked me this question at curl presentation I did recently.

I decided I would count my own installations to see what number I could possibly come up with, ignoring the discussion if I’m actually could be considered “average” in this regard or not. This counting includes a few assumptions and estimates, but this isn’t a game we can play with complete knowledge. But no crazy estimates, just reasonable ones!

I decided to count my entire household’s amount just to avoid having to decide exactly which devices to include or not. I’m counting everything that is “used regularly” in my house (things that haven’t been used within the last 12 months don’t count). We’re four persons in my household. Me, my wife and my two teenage kids.

Okay. Let the game begin. This is the Stenberg household count of October, 2021.

Computer Operating Systems

4: I have two kids who have one computer each at home. One Windows 10 and one macOS. They also have one ChromeOS laptop each for school.

3: My wife has no less than three laptops with Windows 10 for work and for home.

3: I have three computers I use regularly. One Windows 10 laptop and two Debian Linuxes (laptop + desktop).

1: We have a Windows 10 NUC connected to the living room TV.

Subtotal: 11 full fledged computers.

Computer applications

Tricky. In the Linux machines, the curl installation is often shared by all users so just because I use multiple tools (like git) that use curl doesn’t increase the installation count. Presumably this is also the same for most macOS and ChromeOS apps.

On Windows however, applications that use libcurl use their own private build (as Windows itself doesn’t provide libcurl, only the curl tool) so they would count as additional installations. But I’m not sure how much curl is used in the applications my family use on Windows. I don’t think my son for example plays any of those games in which I know they use curl.

I do however have (I counted!) 8 different VMs installed in my two primary development machines, running Windows, Linux (various distros for curl testing) and FreeBSD and they all have curl installed in them. I think they should count.

Subtotal: 8 (at least)

Phone and Tablet Operating Systems

2: Android phones. curl is part of AOSP and seem to be shipped bundled by most vendor Androids as well.

1: Android tablet

2: iPhones. curl has been part of iOS since the beginning.

1: iOS tablet

Subtotal: 6

Phone and tablet apps

6 * 5: Youtube, Instagram. Spotify, Netflix, Google photos are installed in all of the mobile devices. Lots of other apps and games also use libcurl of course. I’ve decided to count low.

Subtotal: 30 – 40 yeah, the mobile apps really boost the amount.

TV, router, NAS, printer

1: an LG TV. This is tricky since I believe the TV operating system itself uses curl and I know individual apps do, and I strongly suspect they run their own builds so more or less every additional app on the TV run its own curl installation…

1: An ASUS wifi router I’m “fairly sure” includes curl

1: A Synology NAS I’m also fairly sure has curl

1: My printer/scanner is an HP model. I know from “sources” that pretty much every HP printer made has curl in them. I’m assuming mine does too.

Subtotal: 4 – 9


I have half a dozen wifi-enabled powerplugs in my house but to my disappointment I’ve not found any evidence that they use curl.

I have a Peugeot e2008 (electric) car, but there are no signs of curl installed in it and my casual Google searches also failed me. This could be one of the rarer car brands/models that don’t embed curl? Oh the irony.

My Peugeot e2008

I have a Fitbit Versa 3 watch, but I don’t think it runs curl. Again, my googling doesn’t show any signs of that, and I’ve found no traces of my Ember coffee cup using curl.

My fridge, washing machine, dish washer, stove and oven are all “dumb”, not network connected and not running curl. Gee, my whole kitchen is basically curl naked.

We don’t have game consoles in the household so we’re missing out on those possible curl installations. I also don’t have any bluray players or dedicated set-top/streaming boxes. We don’t have any smart speakers, smart lightbulbs or fancy networked audio-players. We have a single TV, a single car and have stayed away from lots of other “smart home” and IoT devices that could be running lots of curl.

Subtotal: lots of future potential!


11 + 8 + 6 + 30to40 + 4to9 = 59 to 74 CIPH (curl installations per household). If we go with the middle estimate, it means 66.

16.5 CIPC (curl installations per capita)

If the over 16 curl installations per person in just this household is an indication, I think it may suggest that my existing “ten billion installations” estimate is rather on the low side… If we say 10 is a fair average count and there are 5 billion Internet connected users, yeah then we’re at 50 billion installations

What’s your score?

Coming webinar: getting started with libcurl

Have you been curious about getting your feet wet with doing Internet transfers with libcurl but reasons (excuses?) have kept you away? Maybe it has felt as a too big step to take?

Fear not, on October 21 I’m doing a free webinar on Getting started with libcurl detailing useful first steps on how to get your initial application off the ground!

Sign up here!

The half-hour presentation will include details such as:

  • Basic fundamentals in the libcurl API and a look on the common data types and concepts.
  • Setting up and understanding a first libcurl transfer.
  • Differences between the two primary libcurl transfer interfaces: easy and multi.
  • A look at the most commonly used libcurl options
  • Suggestions on how and where to take the next steps

The plan is to make this presentation work independently of platform, compiler and IDE choice and it will focus on C/C++ code. Still, since most libcurl bindings are very “thin” and often mimics the C API fairly closely, it should be valuable and provide good information even for you who plan to write your libcurl-using applications in other languages.

We’ll also end the session with a Q&A-part of course so queue up your questions!

The presentation will be recorded and made available after the fact.


To participate on the live event, skip over and sign up for it.

The event will take place on October 21, 2021 at 10:00 PDT (check your time zone)


Image by Wokandapix from Pixabay

One new contributor every 3.4 days

In the curl project we keep track of and say thanks to every single contributor. That includes persons who report bugs or security problems, who run infrastructure for us, who assist in debugging or fixing problems as well as those who author code or edit the website. Those who have contributed to make curl to what it is.

Exactly today October 4th 2021, we reached 2,500 names in this list of contributors for the first time. 2,500 persons since the day curl was created back in March 1998. 2,500 contributors in 8599 days. This means that on average we’ve seen one new contributor helping out in the project every 3.44 days for almost twenty-four years. Not bad at all.

The 2,500th recorded contributor was Ryan Mast who brought pull-request 7809.

Thank you everyone who have helped us so far!

As can be seen on the graph below plotting the number of people in the THANKS file, the rate of newcomers have increased slowly over the years and we’ve added new names at the rate of about two hundred per year recently. There’s a chance that we will add the next 2,500 names to the list faster than twenty-four years. The latest 1,000 contributors have been added since the beginning of 2017, so in less than five years.

2,500 contributors to curl

The thanks page on the website is usually synced at release time so it is always a little bit behind compared to what’s recorded in the curl git repository.


The graph bump back in 2005: it was a one-time sweep-up where I went through our entire history and made sure that all names of people who were previously mentioned and who had helped were added correctly to the document. Since then, we’ve kept better track and make sure to add new names as we go along.


We of course collect the names of the contributors primarily by the use of scripts, which is also the best way to avoid some slipping through.

  1. We always mention contributors and helpers in git commits, and they should be “marked” correctly for scripts to be able to extract them
  2. We keep a list of contributors per-release in the RELEASE-NOTES document. When we commit updates to RELEASE-NOTES, we use the fixed commit message ‘synced’ to have our tools use that as a marker.
  3. To get the updated list of contributors since the previous update of RELEASE-NOTES, we use the scripts/contributors.sh script.
  4. At release time, we update THANKS withe the scripts/contrithanks.sh script.

Post-Quantum curl

For some TLS connections you want the secrets you exchange over them to remain private for decades to come.

So what if someone in the future produces a computer system that can crack all the common current encryption algorithms in no time and they already have past secret communications stored?

Such a possible future computer system that might do this is believed to be the quantum computer. There are early and tiny versions of such machines already in existence, but they are far from strong enough to be cracking any strong ciphers today. The question is then how long it takes until they will be able to do that, and thus for how long recorded secret communications can expect to remain secret. 10 years? 20? 30?

If there’s a capable quantum computer made available in let’s say twenty years time, our currently most common TLS ciphers are then rendered next to worthless in twenty years. If you want your communication to remain private even after the introduction of quantum computers, you need post-quantum safe algorithms for your TLS data, and you need a post-quantum curl to use those ciphers for your transfers!

Post-quantum TLS

My colleagues at wolfSSL have recently been working on making sure that the library with the same name has support for a set of ciphers that are post-quantum safe. That work has been merged into wolfSSL’s git repository and will be part of a future pending release. That “future release” is hopefully just a few weeks off now.

In association with that, we’ve also made sure that curl built with wolfSSL can take advantage of these powers. The necessary curl changes for this have landed in git and will be part of the pending curl 7.80.0 release.

Use it with curl

To make your curl transfers post-quantum safe today, all you need to do is:

  1. make sure you have a wolfSSL build and install with the proper algorithms enabled
  2. build curl from git (or wait for the 7.80.0 release) and tell it to use wolfSSL for TLS
  3. specify a post-quantum curve when you invoke curl


curl --curve SABER_LEVEL5 https://example.com

The success of such a TLS 1.3 handshake with a server then of course also requires that you communicate with a server that conversely also supports quantum-safe algorithms. This not terribly common yet.


The primary curl pull-request for this feature was authored by Anthony Hu.

Image by Gerd Altmann from Pixabay