Libtorrent

libtorrent-rasterbar is a bittorrent library written in C++. It is used by popular clients, such as qBittorrent (QT) and Deluge (Python).

I2P Support

The I2P support is available through the SAM bridge in libtorrent. It was broken until late 2022 after a thread on zzz.i2p with several patches being merged upstream.

Issues

Currently (early 2023), the peer count shows the right numbers, but the peer list (both in libtorrent's client_test and qBittorrent) shows only one peer with an IP address of "0.0.0.0:0".
(client_test shows multiple 0.0.0.0's, while qBittorrent shows only one.)

Examples

libtorrent

For libtorrent's client_test program (available with source, a basic full impl. of libtorrent), the following command can be used to leech/seed a magnet (this example shows I2P+'s 2.1.0 Windows installer) through I2P (by Vort):

examples/client_test --enable_dht=false --proxy_type=i2p_proxy --i2p_hostname=127.0.0.1 --i2p_port=7656 'magnet:?xt=urn:btih:889401025a1c16bbf9d8001ae157679507a87feb&dn=I2P%2B+Universal+Installer+2.1.0%2B&tr=http://tracker2.postman.i2p/announce.php'

You can press 'h' within client_test to see the available options.

qBittorrent

For qBittorrent, until the I2P support is added, one needs to build using Jiigen's fork:

git clone https://github.com/jiigen/qbittorrent -b i2p-support jiigen_qbit
cd jiigen_qbit
mkdir build
cd build
cmake ..
make
sudo make install

And within the Settings->Connection->Proxy, one needs to set "Proxy Type" to I2P, the host/port to SAM bridge's host/port, and needs to tick "proxy for peer connections/host lookups".

(Note: One might also want to enable Anonymous Mode. (Settings->BitTorrent->Enable anon.mode))

External links

• https://libtorrent.org - home page
• https://github.com/arvidn/libtorrent - GitHub repository
• https://github.com/qBittorrent/qbittorrent - qBittorrent's GitHub repository