Have you ever tried to solve the following problem? I did. Many times.
You have just finished installing a brand new Internet node, but you need to connect to it (usually using SSH) to perform some tasks. The issue is that this node usually lies behind NAT, does not have a public IP, its local IP keeps changing or even worse even the public IP is changed by ISP from time to time.
This problem is usually solved by port forwarding on a router that has the public IP, but this is not very usable in more complex network environments.
Another option is to create a VPN where you connect your node, but this requires quite a big effort to get it working (both server and client side).
There is another way, which I find quite easy and elegant at the same time. Let’s use a Hidden Service created via Tor network! We don’t really need anonymity in this case, but it comes as a nice bonus.
I will use Raspberry Pi and Raspbian Jessie in this example, but this should work almost anywhere with small changes.
Login to Raspberry Pi and enable SSH daemon if it was not enabled (it is on by default in Raspbian).
All commands below should be run as root, so either spawn a root shell using sudo -i or prepend each line with sudo.
Update the system and install Tor package:
apt-get install tor
Edit the Tor configuration file /etc/tor/torrc and add the following lines:
This is how it looks when you approach the tag with this app running:
The most important thing on the last screen are dots that appear between the sector number and its contents. This means that the area is unlocked and writable (x means locked, . unlocked). Yay!
Why is the tag not locked and anyone can write to it? I can only speculate, but I think that’s because the advertisement company uses the tags to track which frame has which ad and they care only about the tag ID, which cannot be overwrittern.
Now when we approach the tag with the phone, Android will read the tag, interpret the URL and open browser with this address.
The information on the tag can be used to trigger lots of other events too. Call a number, send an email, launch an application, show plain text or send or receive bitcoins (when bitcoin:address URI scheme or Bitcoin private key is used).
When we use the TagInfo application now, it will look like this:
When I was experimented with the tags, I haven’t found any which had any data stored in it.
I hope next time I try this, there will be some nice poems (106 chars maximum) or links to some nice pictures.
Heck, someone could even create an interesting augmented reality game, capture the flag, check-in (who wants to be a mayor of this train?) or …
The only limit is your imagination. And slow (or none) internet in the metro. :-(
Beginning of January Netflix expanded to most of the countries all around the world. The domination map looks quite impressive:
Unfortunately, the reality is not as bright as it looks. When I read the announcement, I did not hesitate and subscribed the service. I was very disappointed to see that most of my favorite shows were not available in my country and I cancelled the renewal of my subscription.
Later, I stumbled upon a website that maintains the list of Netflix content per country called uNoGS (unofficial Netflix online Global Search). I was very interested to see how my country stands when compared to the others. Sadly there was no visualization of uNoGS data on their site, so I came up with my own using the interactive Google Charts API:
Recently, I decided to support some of the open-source distributed projects such as Tor, IPFS and Bitcoin.
One way of supporting them would be to send some money as a donation,
but because I am a hacker with a good Internet connection I decided to build a computer node that will directly contribute to their networks and make them bigger and more robust.
I call it a “Freedom Node”.
I evaluated lot of options and ended up buying the following components from my local computer hardware supplier:
(If you want to use Bitcoin XT instead of Bitcoin Core just use bitcoinxt-server package instead of bitcoin-server in the line above.)
Edit the Tor configuration file /etc/tor/torrc and uncomment the following lines (the first line opens the relay port, the second one enables the directory service, the third one disables the exit node):
ExitPolicy reject *:*
Also fill in the details on lines with Nickname and ContactInfo.
If you are more adventurous you might skip uncommenting the ExitPolicy reject line, but I recommend reading something about running an Exit Node first.
Edit the Bitcoin configuration file /etc/bitcoin/bitcoin.conf and change RPC password to something random: