I was wondering on how to make file on my Raspberry Pi encrypted and I ended up making a script that did it for me.
It's based on ecryptfs filesystem for linux with aes cipher.
📌 Basically this allows you to mount encrypted folder if it's unmounted and dismount it when you're done.
It checks if the determinated folder is mounted, if so the script unmount it, otherwise the script will mount it with a 16 bytes aes encryption level, asking you for a password.
📌 Running this script twice will allow you to mount encrypted folder and unmount it.
📌 You need the folder mounted to read and write file and unmounted to have them encrypted.
BEFORE STARTING THE SCRIPT READ ALL
First of all you need to update the repositories and install ecryptfs
sudo apt-get update
sudo apt-get install -y ecryptfs-utils lsof
Then you have to create a directory: the one you want to encrypt
mkdir ~/secret-folder
N.B. before put files into the folder mount it with encryption at least one time
Finally download the script and edit it by replacing the variable DIR with the path to your folder
nano ~/crypt.sh
You can also change the bytes for the encryption level at the variable bytes. Possible levels: 16, 24, 32.
You need to give to the script execution privilege with this command
chmod +x crypt.sh
The run it
./crypt.sh
The first time the folder is unmounted so you will prompted for the encryption password.
Then, only this time, you need to answer yes to both questions.
More Knowledge
The first question warn you saying that you never used the password, that is correct from the moment that's the first time you use it, or you could have typed it wrong.
The second one ask you if you want to avoid this warning in future everytime you insert this password