Posts tagged with: ubuntu

Encrypting a tar or gz (gzip) File with OpenSSL

When you have sensitive data that you need to transmit but want to make it easy to encrypt and decrypt it, use some standard tools to get the job done!

I recently had an issue where a client was using OS X laptops running an Admin panel written in PHP on MAMP in an environment that may or may not have an internet connection. The problem was that they needed to be able to dump their database data into an encrypted file so that they could send the data off when they get a connection (via email, upload, who knows). My initial response was to use gpg to encrypt the file and hand out the keys to the people who would eventually be reading the data.

Turns out, this was going to be a nightmare and I needed something ‘easier’. How about encrypting a tar file with OpenSSL? Bingo! This solution uses utilities that are already on the machine and no installations need to be performed. The reason this was such a big deal is because the laptops running this software will be all over the world with various levels of technical acumen and it will be a nightmare to make sure every single laptop has been updated correctly.

Encrypting Your File

tar and gzip the file, then encrypt it using des3 and a secret key.

That simple!

Decrypting Your File

Essentially, just call all the commands in the reverse order.

Download the Utility Scripts

Download them!

Measuring Download Speed from Linux Command Line

I recently needed to test the network speed of the ISP from my Ubuntu 10.04 LTS server. I was trying to think of a better way to test it than going out to a Linux Distro's web site and downloading an ISO from them. I stumbled across this post on StackOverflow that had a URL to a test file and my speedtest scripts were born. I created two scripts; one utilizing wget and one utilizing curl. A lot of machines don’t come with curl by default, but it has a lot more output than wget does while downloading.


What Do They Do?

The scripts utilize wget or curl to download the 500M test file and you can view the speed results in real time. This is an entirely unscientific method of testing your speed, but much better than say, going to Ubuntu and downloading their latest ISO via wget. Finally, the output is set to go to /dev/null, which means it simply throws away everything it downloads (no cleanup).


The Code

Download both scripts here