A darknet (or dark net) is an overlay network that can only be accessed with specific software, configurations, or authorization, often using non-standard communications protocols and ports.
Well known example of the darknet is the Onionland -- public darknet created with Tor software. This article will show you how to create your own darknet with Invisible Internet Protocol (I2P) for fun and profit. Unlike the Onionland, it will be fully distributed and suitable for any type of private and anonymous communications.
How own darknet can be useful
Online privacy and anonymity research
You can run your own network to study how anonymous networks work, find their weaknesses and performance improvement possibilities.
Anonymous network layer can be added to any filesharing software, for example, to torrent clients and apps like PopcornTime. Users will download and share content anonymously, torrent-trackers can work anonymously in these networks too.
Nextgen VPN/proxy providers can use this technology to create truly trustless service. Users will mix their traffic with each other and use regular Internet through provider's "exit nodes".
I2P network overview and terminology
I2P (Invisible Internet Protocol) is a universal anonymous network layer. All communications over I2P are anonymous and end-to-end encrypted, participants don't reveal their real IP addresses.
I2P client is a software used for building and using anonymous I2P networks. Such networks are commonly used for anonymous peer-to-peer applications (filesharing, cryptocurrencies) and anonymous client-server applications (websites, instant messengers, chat-servers).
I2P uses special virtual addresses called destinations instead of IP address. Noone can track what real IP address owns a given destination.
Also, I2P network uses a specialized distributed database called netDb for routing. Regular clients just store their netDb localy, but there is a special mode called floodfill, which makes the node to maintain and distribute netDb to others.
To join I2P network client needs to get some initial netBb items. This process is called "reseeding". Reseed server is a public HTTPS server which hosts signed archive with netDb items. Actually, clients can reseed in many other ways (including manual reseed from friends), HTTPS reseed is just the easiest way.
So, what needs to be done to create fully-functioning I2P darknet:
- run some I2P clients in the "floodfill" mode
- create a public "reseed" server, which will help new clients to bootstrap into I2P network
- create I2P client bundle for new users
For demonstration purposes I will set up test network using LXC virtualization on a single Ubuntu 16.04 host. You can do similar steps with real computers in the Internet/LAN/CJDNS/etc, if you really want.
As I2P client I will use lightweight C++ implementation i2pd.
As a reseed server I will use pyseeder.
Prepare host system
# Install LXC and build tools sudo apt-get install lxc bridge-utils build-essential git # Install python3 with utilities and dependencies for building # python-cryptography (for pyseeder) sudo apt-get install python3 python3-pip python3-virtualenv \ libssl-dev libffi-dev python-dev # Prepare a working directory for lxc-testnet project # Note that I will use $WDIR variable in many other shells export WDIR=$HOME/lxc-testnet mkdir $WDIR # Download my set of shell scripts for managing LXC testnet git clone https://github.com/l-n-s/i2pd-testnet-framework.git $WDIR # (Optional) For some reason, apparmor in my Ubuntu box breaks LXC, so I disabled it # You could try to find another solution sudo systemctl stop apparmor && sudo systemctl disable apparmor
Build static i2pd
build_static_i2pd.sh in the working directory.
cd $WDIR && ./build_static_i2pd.sh
It will build static i2pd binary with all dependancies included, so you can copy it to other machines (with the same architecture) and it will just work.
# Download pyseeder and install it's requirements cd $WDIR git clone https://github.com/PurpleI2P/pyseeder.git cd $WDIR/pyseeder virtualenv --python=python3 venv . venv/bin/activate pip3 install -r requirements.txt deactivate
Open a new shell to do all pyseeder operations there and activate virtual environment:
cd $WDIR/pyseeder . venv/bin/activate
Generate a new keypair for the reseed server. Just for this example, set "dadadada" as password:
./pyseeder.py keygen --signer-id firstname.lastname@example.org
This will create files
data/priv_key.pem. It is reseed public certificate for distributing with i2pd and private key for creating SU3 files and run HTTPS server.
By default, Ubuntu host exposes to LXC network interface
lxcbr0 with IP address 10.0.3.1. So reseed URL will be:
Create binary distributive
For demonstration purposes, I will only create a distributive for Linux boxes.
# Create distributive folder and copy static binary to it mkdir -p $WDIR/dist cp $BUILD_DIR/src/i2pd/i2pd $WDIR/dist # Copy reseed certificate mkdir -p $WDIR/dist/certificates/reseed cp $WDIR/pyseeder/data/mark_at_mail.i2p.crt $WDIR/dist/certificates/reseed
You will need to distribute this package with configuration file
i2pd.conf for your network.
./testnetctl re-install command generates
i2pd.conf and run/stop scripts from
templates/ folder, so it's all automated with LXC testnet.
docs/i2pd.conf config file in i2pd repository if you wish to create network with real computers.
Create 12 virtual computers with LXC and copy i2pd distributive there.
# Create 12 LXC containers (5 of them will be floodfills) sudo ./testnetctl prepare 12 # Install i2pd to LXC containers sudo ./testnetctl re-install
Now it is time to run some floodfill nodes and collect their
You can manually copy
router.info files from your machines, but make sure you name it as
something-random.dat, because pyseeder looks for .dat files.
# Collect reseed data: run and stop i2pd to generate router.info file, then copy this file to netDb folder sudo ./testnetctl collect_reseed_data
Almost there! Create a reseed file (i2pseeds.su3) from netDb folder. Swith to pyseeder shell and run:
echo "dadadada" | ./pyseeder.py reseed --signer-id email@example.com --netdb $WDIR/netDb
Run HTTPS reseed server (script will prompt for a password, it is still "dadadada"):
./pyseeder.py serve --host 0.0.0.0 --cert data/mark_at_mail.i2p.crt
Run I2P network:
sudo ./testnetctl run
Notice in pyseeder shell that clients are downloading .su3 file. After that, nodes will start discovering each other.
Open a new shell to run monitoring script:
cd $WDIR/monitoring ./scanner.sh iplist.txt watch -n1 ./i2pd_monitor.sh iplist.txt
This simple script will display real-time statistics of all nodes in the network.
If the task is to reinstall i2pd folder
dist to all containers:
sudo ./testnetctl re-install
If the task is to reinstall just
sudo ./testnetctl re-install-binary
Stop the network:
sudo ./testnetctl stop
To clean host system after experiments (delete all containers):
sudo ./testnetctl clean
So, what's next?
Try to analyze network traffic between nodes and you'll notice that it's all mixed and encrypted. It's impossible to know for sure if someone is hosting a website in I2P, or using torrents, or just routing transit traffic.
If you have any questions, feel free to ask them at Freenode IRC channel #i2pd-dev.