Linux Brain Dump

Did you know that Email is sent in clear text over the Internet? Yeah, it is, and unless you take steps to secure it, anyone who intercepts a message can easily read it. It’s also really easy for someone to send an email that looks like it came from you. The open source solution for this problem is called GNU Privacy Guard. It uses public key cryptography to encrypt a message, so that only the rightful recipient can read it, or simply sign it so that the recipient can confirm that it came from you. Here’s an installation walk-through for GNU Privacy Guard on Fedora and Ubuntu, along with a brief overview of how to use it with Evolution to send secure email.

Installation
The first thing you need to do is get the necessary software installed. Gpg is a console program, but there’s an awesome GUI called Seahorse which makes using gpg easy. To install seahorse, go to Applications -> Add/Remove Software, search for and install seahorse, or use the command line to install it.
Fedora (as root):

yum -y install seahorse

Ubuntu:

sudo apt-get install seahorse

Everything from here on out is the same for both systems.

Creating Keys
The first thing you’ll need to do is generate a key pair. To do this, launch seahorse. It’s found under Application -> Accessories -> Passwords and Encryption Keys. Click on New and the bottom of the window. Select PGP key and click OK. Enter your name, email address and a comment if necessary, then click OK. Enter a secure password in both fields and click OK. You should see it creating the keys. This can take a while. When it’s finished, you will see your new key in the list.

Publishing Keys
After creating your key pair, publish it so that others can retrieve it if necessary. Right-click on the key, and select Sync and Publish Keys. On the Sync Keys window, click on Key Servers. At the bottom of the Encryption Preferences window, select the pgp.mit.edu server from the “Publish Keys To” drop-down box. Click on Close, then click on Sync.

Configure Evolution
Assuming you already have Evolution configured to retrieve your email, click on Edit and select Preferences. Select your email account from the list and click edit. Click on the Security tab in the Account Editor window. Enter your Key ID in the appropriate field. It’s displayed on the My Personal Keys tab in the Passwords and Encryption Keys window, and choose whether or not to always sign or encrypt; then click OK and you’re done.

Now that you have secure email, read this article to see how to use Seahorse to setup key based authentication for SSH.

Got more tips on securing email? Let’s hear them in the comments!