/smtp_to_tcp

Tunnel a TCP connection by sending emails. It's so ridiculous, it had to be done.

Primary LanguagePythonMIT LicenseMIT

email_to_tcp

Tunnel a TCP connection by sending emails. It's so ridiculous, it had to be done.

Backstory

You've woken up and found yourself in the middle of a desert with only one tool: a satellite phone with access to a single email account. You really, really want to check reddit. It's time for smtp_to_tcp.

Set up

WARNING: If you give it the chance, this code will kill you and everyone you care about.

Make sure to thoroughly test all of these settings before you embark on a journey into the desert, and note that the code is not designed for high-reliability needs. You've been warned.

Basic requirements

While you can test-drive this software with only one computer, you'll only be able to use it in the desert if you've set up at least two computers. We'll call these computers the local and the remote machines.

  • The local machine lets you browse the internet using your email connection. The local machine needs access to an SMTP and IMAP server.

  • The remote machine reads emails from the local machine and fetches the requested data from the internet. The remote machine should have unfettered access to the internet.

If you just want to test-drive the code, open up two different terminals, one for the local machine and one for the remote machine.

(TODO: Picture illustrating this basic architecture)

Note: The code uses IMAP IDLE push notifications to lower the latency of the connection somewhat. This works well for Google's Gmail, but some email providers do not support this convenient protocol (cough Yahoo! cough). Use your [google fu] google-fu to check that your email supports IDLE push.

Installation (both machines)

To start, first install python3 and pip3 on both the local and remote machines. The code was tested with python 3.4, and your mileage may vary with different versions.

You'll also want to install the packages listed in requirements.txt. The pip package manager makes the process painless:

 >> pip3 install -r requirements.txt

Setting up your remote machine

To start the server on the remote machine, run the following code

>> python3 -m email_to_tcp.remote

You will be prompted with a series of questions about your email username and password. If you see a success message, you are good to go. This process needs to be running as long as you want to access the internet.

Setting up your local machine

This service requires a bit more work. First, we start the local proxy server:

>> python3 -m email_to_tcp.local

You'll again be prompted with a series of questions. Make sure that the email-to address matches the email account that the remote machine is monitoring.

Once you see the success message, it's time to tell your browser to use this special proxy server to access the internet. The following instructions apply to Firefox on a Mac.

  1. Install Firefox.
  2. Go to Preferences -> Advanced -> Network and click on Settings...
  3. Click the radio button Manual proxy configuration: and set the HTTP Proxy to 127.0.0.1 and Port to 9999. Leave the other boxes blank.
  4. Click OK.

If everything works, you should be able to access the internet. Try hacker news or reddit.

NOTE Secure HTTPS connections will not be tunneled through your email.

Questions?

Submit an issue, or email me at my_address, where

 my_address = '.'.join(['michael', 'b', 'mccoy', '@', 'gmail', 'com'])

TODO

  • Support HTTPS

  • Support IMAP servers that don't use IDLE push notifications

  • Multi-thread requests

  • Write meaningful tests