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{% extends "common/base.j2" %}
{% block body_content %}
<article class="container">
<!--<article> -->
<header>
<h2>{{ _("How to use GNUnet - in a nutshell") }}</h2>
</header>
<section>
<h3>{{ _("Make sure your GNUnet installation works...") }}</h3>
<p>
... and play around with it. So let's try out some of GNUnet's use cases. Please mind that some should be done in a particular order, one after another:
</p>
<ul>
<li>filesharing</li>
<li>A simple chat using CADET</li>
<li>Name resolution using GNS on the command line</li>
<li>Name resolution using GNS with a browser (do it on the command line first)</li>
<li>Serving a website using VPN (do name resolution with a browser first)</li>
</ul>
</section>
<section>
<h4>{{ _("filesharing") }}</h4>
<p>
Let's publish a file in the GNUnet filesharing network. We use the keywords
("commons" and "state") so other people will be able to search for the file.
</p>
<p>
We can choose any file and describe it with meaningful keywords (using the
`-k` command line option).
</p>
<code>
$ gnunet-publish -k commons -k state ostrom.pdf<br>
Publishing `/home/myself/ostrom.pdf' done.<br>
URI is `gnunet://fs/chk/M57SXDJ72EWS25CT6307KKJ8K0GCNSPTAZ649NA1NS10MJB4A1GZ9EN4Y02KST9VA5BHE8B335RPXQVBWVZ587Y83WQ7J3DHMBX30Q8.DHNGBN4CB2DBX1QRZ1R0B1Q18WTEAK4R94S9D57C9JMJJ3H7SSQDCV4D1218C4S2VP085AMQQSMG18FCP6NQMZQZJ91XR5NBX7YF0V0.42197237'.
</code>
<p>
Finding the file by keyword works with `gnunet-search`.
</p>
<code>
$ gnunet-search commons<br>
#1:<br>
gnunet-download -o "ostrom.pdf" gnunet://fs/chk/M57SXDJ72EWS25CT6307KKJ8K0GCNSPTAZ649NA1NS10MJB4A1GZ9EN4Y02KST9VA5BHE8B335RPXQVBWVZ587Y83WQ7J3DHMBX30Q8.DHNGBN4CB2DBX1QRZ1R0B1Q18WTEAK4R94S9D57C9JMJJ3H7SSQDCV4D1218C4S2VP085AMQQSMG18FCP6NQMZQZJ91XR5NBX7YF0V0.42197237
</code>
<p>
It gives us the command line call to download the file (and store it as
ostrom.pdf)!
</p>
</section>
<section>
<h4>{{ _("CADET (and Chat)") }}</h4>
<p>
We can use the `gnunet-cadet` command line tool to open a port and from
another machine connect to this port and chat or transfer data. First we need
our *peer ID* of the GNUnet peer opening the port.
</p>
<code>
$ gnunet-peerinfo -s<br>
I am peer `P4T5GHS1PCZ06R82D3KW8Z8J1113BQZWAWGYHTZ8G1ZXMWXQGAVG'.
</code>
<p>
Now we open the port (it can be any string!):
</p>
<code>
$ gnunet-cadet -o my-secret-port
</code>
<p>On the other machine we can connect using the peer ID and the port and start chatting!</p>
<code>
$ gnunet-cadet P4T5GHS1PCZ06R82D3KW8Z8J1113BQZWAWGYHTZ8G1ZXMWXQGAVG my-secret-port
</code>
</section>
<section>
<h4>{{ _("Name resolution using GNS on the command line") }}</h4>
<p>GNS is the GNU name service, a fully decentralized alternatice to DNS. We'll publish an IP address in a GNS record try to resolve it on the command line. First we need an identity which is the
equivalent to a zone in DNS. We'll call it "myself" and create it using the
`gnunet-identity` command line tool. Instead of "myself" you can surely use your
nick or any other name. </p>
<code>
$ gnunet-identity -C myself
</code>
<p>We can check if it worked using the same tool. We expect the name of our identity and the corresponding public key to be displayed.</p>
<code>
$ gnunet-identity -d<br>
myself - HWTYD3P5D77JVFNVMZ1M5T10V4SZYNMY3PCGQCSVENKD6ZCRKPMG
</code>
<p>
Now we add a public `A` record to our zone. It has the name "ccc", a value
of "195.54.164.39" and it expires after one day.
</p>
<code>
$ gnunet-namestore -z myself -a -e "1 d" -p -t A -n ccc -V 195.54.164.39
</code>
<p>Now we can query that record using the command line tool `gnunet-gns`.</p>
<code>
$ gnunet-gns -t A -u ccc.myself<br>
ccc.myself:<br>
Got `A' record: 195.54.164.39
</code>
<p>
So it worked! But only resolving our own records is boring. So we
can give our identity (the public key of it to be precise) to
someone else so they can try to resolve our records, too. The
other person (Bob) has to add it to his namestore like this:
</p>
<code>
$ gnunet-namestore -z myself -a -e never -p -t PKEY -n alice -V HWTYD3P5D77JVFNVMZ1M5T10V4SZYNMY3PCGQCSVENKD6ZCRKPMG
</code>
<p>
Our identity in Bobs namestore is a public record (-p) and never
expires (-e never). Now Bob (let's assume he has called his
identity myself, too) should be able to resolve our "ccc" record,
too!
</p>
<code>
$ gnunet-gns -t A -u ccc.alice.myself<br>
ccc.alice.myself:<br>
Got `A' record: 195.54.164.39
</code>
<p>
It can continue like this. A friend of Bob would be able to
resolve our records too because Bob published our identity in a
public record. Bobs friend would simply use "ccc.alice.bob.myself"
to resolve our "ccc" record.
</p>
</section>
<section>
<h4>{{ _("Name resolution using GNS with a browser") }}</h4>
<p>
In the previous use case "Name resolution using GNS on the command line" we got an idea
about what GNS is about, but now let's use it with a browser, to make it actually useful. Currently Firefox and Chromium are known to work.
</p>
<p>
Many websites enforce HTTPS and thus provide certificates for
their hostnames (and not our GNS names). Browsers don't like wrong
hostnames in certificates and will present error messages. So GNUnet
has to trick them by generating own certificates for our GNS
names. This means we need to create our own certificate authority
and tell our browser about it. Luckily there's a script for it:
</p>
<code>
$ gnunet-gns-proxy-setup-ca
</code>
<p>After executing this script the Browser has to be restarted.</p>
<p>
GNUnet provides a proxy service (gnunet-gns-proxy) that the
browser can send DNS and HTTP traffic to. It will try to resolve
names with GNS first and forward the rest of the DNS traffic to
the system's DNS resolver. It will also take care of the HTTP
traffic, so the browser gets valid certificates and the web server
will not be confused by our GNS hostnames. Our GNS namestore
doesn't know about any DNS hostnames yet, so we have to store
them, too. For our "ccc" A record, we have to store a LEHO (legacy
hostname) record, too. It must contain the website's original DNS
hostname:
</p>
<code>
$ gnunet-namestore -z myself -a -e "1 d" -p -t LEHO -n ccc -V www.ccc.de
</code>
<p>Now let's start gnunet-gns-proxy.</p>
<code>
$ /usr/lib/gnunet/libexec/gnunet-gns-proxy
</code>
<p>
Our browser has to be configured so it uses our proxy. In Firefox
we have to set these options under "about:config":
</p>
<code>
network.proxy.socks: localhost<br>
network.proxy.socks_port: 7777<br>
network.proxy.socks_remote_dns true<br>
network.proxy.type: 1
</code>
<p>
To tell Chromium to use the proxy, it has to be started with the
"--proxy-server" command line option:
</p>
<code>
$ chromium --proxy-server="socks5://127.0.0.1:7777"
</code>
<p>
Now we should be able to resolve our GNS names in the browser! We
just have to type "https://ccc.myself" into the address bar. If
our friend Bob prepared his system, too, he can resolve our record
by typing "ccc.alice.myself".
</p>
</section>
<section>
<h4>{{ _("VPN") }}</h4>
<p>
TBD
</p>
</section>
</article>
{% endblock body_content %}
|
