Gopherism

Installation

pip3 install -r requirements.txt

Guide

Start the Gopher server using:

python cli.py serve -H 127.0.0.1 -p 443 -d pub/ -tls -A

• -H: advertised host (default: 127.0.0.1)
• -p: port to use for Gopher (default: 70)
• -d: directory to serve gopher items from (default: 'pub/')
• -tls: indicates to enable TLS encryption (default: False)
• -http: indicates to create a HTTP server that runs in separate thread (default: False)
• -http_port: port to use for HTTP (default: 8080)
• -A: special handler to include database search and comment section

To spin up a Gopher client, I am using VF-1. After running the above CLI command, in a separate terminal, do:

python vf1.py

You should see the VF-1 command line Gopher client appear. To enable TLS encryption, type tls. To go to your hosted gopher site, enter go gopher://localhost:<PORT>. See the images below for an example interaction.

Localhost

Public Gopher Site

Packet Capturing with Wireshark

TCP packets Gopher operates over TCP. You can filter for these packets in Wireshark using tcp.port == <PORT>> after spinning up the Gopher server and connecting to it:

TLS To capture TLS packets, you need to deploy your Gopher server with TLS encryption, as explained in the guide earlier. Note that for demonstration purposes, a self-signed certificate and private key for TLS has been generated via

openssl req -x509 -newkey rsa:4096 -keyout privkey.pem -out cacert.pem -days 365 -nodes

and stored in the /tls folder. Because the certificate is self-signed, this can pose an issue for loading the site. As such, I disabled SSL certificate verification in lines 455-458 of vf1.py:

if self.tls:
    context = ssl.create_default_context()
    context.check_hostname = False  # Disable hostname checking
    context.verify_mode = ssl.CERT_NONE  # Disable certificate verification
    s = context.wrap_socket(s, server_hostname = gi.host)

This allows us to bypass the certificate verfication error. For analyzing packets over Wireshark, default port should be 443. To verify, go Wireshark > Preferences > Protocols > HTTP to see the default port number for "SSL/TLS Ports" in settings. It is important to match the port else the TLS packets won't be labelled properly. You should start seeing TLS-encrypted packets appear in Wireshark when you filter for tls:

References

The implementations for the Gopher server is referenced from Pituophis amd the terminal from VF-1: VF-1 Code VF-1 Docs Pituophis Github Pituophis Old Docs (with TLS)