2.6 KiB
deHTTPS-Proxy - Access HTTPS Websites from Retro Computers
Purpose
Today's web is based around Transport Layer Security (TLS) protocols, namely HTTPS. In the last couple of years many sites that were previously available in plaintext have been made HTTPS-only. This renders them inaccessable to retro computers such as the Apple II, which are not capabable of handling the cryptography.
I had the idea of building an HTTP to HTTPS gateway, which allows requests to be submitted in plaintext HTTP and forwards them in HTTPS, acting as a kind of proxy.
This particular implementation dehttps-proxy.py is a quick and dirty hack
using Python 3. The error handling is rather rough-and-ready but it does
work fairly well in practice.
Configuration
Edit dehttps-proxy.py and set the PORT to the desired value. This will
usually be port 80, the normal HTTP port. You may also want to add any
top level domains you use to the list tlds = [ ... ]. This currently just
has the common ones (.com, .net, .gov etc.)
If you are using port 80 you will have to run the script as root:
sudo ./dehttps-proxy.py
Using the Proxy
I used the Contiki WEBBROWS.SYSTEM program on the Apple II for testing,
but you can also use a modern browser such as Chromium or Firefox.
Suppose you want to browse https://www.example.com/path/to/page. Enter
the following as the URL in your browser:
http://pi/www.example.com/path/to/page, where pi is the hostname of
your Raspberry Pi (or whatever system you are using to host the proxy.)
Your request will go to port 80 (HTTP) on the server pi where it will be
handled by dehttps-proxy.py. The Python script adds https:/ to the path
that was passed in (/www.example.com/path/to/page in this instance) and
performs the HTTPS request. The data that is obtained is returned to the
original HTTP requester in plaintext.
Trick to Make Links Work (within a site)
Many links on webpages are internal to the site. These links are specified
using a relative rather than a fully qualified URL. dehttps-proxy.py uses
a trick to make these internal links work. When a fully qualified URL like
www.example.com/path/to/page is requested, the code keeps track of the
website domain www.example.com. The https://www.example.com/ prefix is
added to Subsequent relative links with URLs such as path/to/another_page.
This trick does not work for links to other websites. If you click on a
link https:://foo.com then you will have to edit it to read
http://pi/foo.com and resubmit it in the browser.
Error Handling Sucks
Error handling consists of catch the error and hope for the best. This could be improved.