TwitSecret

University of Waterloo CS 858 Final project, Fall 2010 Kartikaya Gupta and Pengfei Zhang

This project provides a Firefox plugin that allows users to encrypt their tweets such that they are only readable by the specified recipients. The plugin inserts a "TweetSecretly" button next to the regular "Tweet" button on the Twitter home page to allow the user to select the intended recipients. It also replaces the tweet stream with one where tweets are decrypted, and undecryptable tweets are filtered out.

In terms of architecture, there is a C component (src/*.c) which uses libgcrypt to provide the required crypto primitives. The binary that is produced from that code is installed into ffext/backend and shipped as part of the plugin. It is invoked via Firefox's nsIProcess API and reads and writes to files in ~/.twitsecret/ since I didn't have the time to figure out Firefox's API for streams to nsIProcess.

The script in libs/ downloads and builds the gnupg-ecc library, which is supposed to contain a version of libgcrypt with ECC encryption/decryption support. I could never get that working, so you can mostly ignore it. The script may still be useful if you don't have libgcrypt to build the binary and don't want to install it on your system globally.

The Firefox XUL UI integration is minimal. The bulk of the hard work is done in ffext/chrome/content/twitsecret.js, which has almost all of the script code used to make the plugin work.

Note that as it stands there are a number of things that need to be done before the plugin is usable by anybody other than me. The two main things are compiling the binary for your platform and installing it into the appropriate subfolder in ffext/backend. The second is obtaining API keys from Twitter so that the plugin can actually use the API. You will need to register a Twitter application at dev.twitter.com and put the consumer key and the secret key into ffext/chrome/content/secrets.js like this:

___twitsecret.keys = { consumerKey: 'MY_CONSUMER_KEY', secretKey: 'MY_SECRET_KEY' }

After that you can bundle the ffext folder into a xpi file, or just point a text file called "[email protected]" to the ffext folder and install that to your Firefox extensions folder to get it working.

Good luck!