YaCy Logo

Introduction[edit]

YaCy ^[archive] is a p2p, censorship resistant Libre search engine. It can be configured to crawl the Internet and private intranets. ^[1] The YaCy website states: ^[2]

YaCy is a free search engine that anyone can use to build a search portal for their intranet or to help search the public internet. When contributing to the world-wide peer network, the scale of YaCy is limited only by the number of users in the world and can index billions of web pages. It is fully decentralized, all users of the search engine network are equal, the network does not store user search requests and it is not possible for anyone to censor the content of the shared index. We want to achieve freedom of information through a free, distributed web search which is powered by the world's users. ... The resulting decentralized web search currently has about 1.4 billion documents in its index (and growing - download and install YaCy to help out!) and more than 600 peer operators contribute each month. About 130,000 search queries are performed with this network each day.

This means it is unnecessary to rely upon centralized professional search engines and their proprietary software. Instead, hundreds of peer operators can serve search queries in a decentralized fashion.

How-to:[edit]

Install[edit]

Warning:

It is currently impossible to securely install YaCy because the associated repository is not signed; see here ^[archive] for further details.
The official installation instructions ^[archive] are non-functional for Debian buster.
The following method is functional but insecure. It should only be attempted in a standalone Whonix-Workstation ™ (Qubes-Whonix ™: Whonix-Workstation ™ TemplateVM).

1. Update.

sudo apt update

sudo apt update

2. Install openjdk-11-jre-headless. ^[3]

sudo dpkg --configure -a

sudo dpkg --configure -a

sudo apt install -y openjdk-11-jre-headless

sudo apt install -y openjdk-11-jre-headless

3. Confirm the latest YaCy package.

Navigate to http://latest.yacy.net/ ^[archive] to identify the latest available YaCy software package. At the time of writing, this was yacy_v1.922_20191013_9964.tar.gz.

4. Download and install the YaCy package.

Qubes-Whonix ™: wget is restricted in the Whonix-Workstation ™ TemplateVM. It is necessary to download the package with Tor Browser and move it manually to the TemplateVM.
Non-Qubes-Whonix ™: Run the following command; replace the package with the latest available version.

wget http://latest.yacy.net/yacy_v1.922_20191013_9964.tar.gz

wget http://latest.yacy.net/yacy_v1.922_20191013_9964.tar.gz

5. Decompress the tar archive.

tar xfz yacy_v1.922_20191013_9964.tar.gz

tar xfz yacy_v1.922_20191013_9964.tar.gz

6. Launch YaCy.

Qubes-Whonix ™ note: launch YaCy in a standalone anon-whonix-yacy AppVM.

cd yacy

cd yacy

./startYACY.sh

./startYACY.sh

To read more on managing YaCy, consult the official documentation ^[archive].

Tor Browser Proxy Exception[edit]

A proxy exception must be configured in Tor Browser to interact with YaCy. Tor Browser blocks communication with localhost to mitigate some fingerprinting attacks. ^[4] Note that this exception has fingerprinting implications in the event a website actively abuses JavaScript, but it is still far safer than using another browser. ^[5] To completely mitigate the risk, it is advised to disable scripts globally with the NoScript extension and only permit JavaScript when absolutely necessary; a sensible anonymity practice.

Note: The following steps will no longer be required once Whonix ™ releases a custom Tor Browser for connecting to alternative networks. ^[6]

Configure Tor Browser to connect to localhost.

Warning:

This step changes the web fingerprint of Tor Browser!
Leave all other settings as is!

In Tor Browser:

Type about:config into the URL bar.
Press Enter
Search for network.proxy.no_proxies_on
Set to 0
Search for network.proxy.allow_hijacking_localhost
Set to false

Usage[edit]

To access the WebUI, copy 127.0.0.1:8090 into the URL bar of Tor Browser and press Enter.

Note: YaCy cannot be integrated with Tor Browser because the official YaCyBar add-on ^[archive] from Mozilla is incompatible with Firefox Quantum and was last updated in 2011. Unless the add-on code is revamped, this option will remain impossible at present.

Figure: YaCy in Whonix ™

Development[edit]

SOCKS proxy support is very unlikely in the near-medium term, as the relevant developer ticket has not been updated since 2013, see: Support for "Remote" SOCKS Proxies ^[archive].