Protecting your data with two factors and ZFS dataset encryption
It’s really easy to use ZFS dataset encryption to protect your data in a way so you have to know something and to own something to get access to encrypted data.
The idea is pretty simple and obvious. One USB drive is your datastore, the other one is your keystore. An dataset on this datastore is encrypted with a file as the source of the encryption key. This keysource is on the keystore USB drive. However it’s not stored unencrytped there. This USB drive contains an encrypted dataset with your keyfile for the dataset on your data store usb stick. However this one is protected with a pass phrase.
Let us “format” the USB sticks with ZFS at first. In this case, the
rmformat command is quite handy to find out about the names of the USB drives in the device tree.
Okay, let’s create the pools:
Afterwards we create an dataset with a passphrase:
Everything we write into this dataset will be encrypted and will be just available to you, when you enter the passphrase. We will write a file with our key for the real data into this dataset. So the key is protected by the passphrase, because without passphrase you can’t encrypt the dataset with the key file (and without key file you can’t decrypt the dataset containing the data).
Creating a keyfile is fairly easy with Solaris. We can use the
pktool tool for it.
With this file as a keysource we create the dataset for our secret files on the second USB drive.
Let’s move some data into this directory:
Now we export the usb drives in order to remove them from the system.
Okay, now you can unplug both USB-sticks and put one in your safe and one at your keyring or in a different safe.
After a while you need to access your data. You need the key source, so you have to import the
Now you have to import your
It doesn’t ask for the keyfile because the location is stored in the metadata of the dataset. And this location is one in the encrypted dataset on the keystore usb stick. As long as the file
/a_keystore_usbstick/keys/joergsdatastick.key is available and it’s containing the correct key, it will automatically decrypt the data. However as mentioned before, it’s just available when you imported the pool
a_keystore_usbstick with the correct passphrase.
This way you need to know the passphrase for the dataset storing the key and you need the USB stick containing the keysource. Without having both, you can’t decrypt the encrypted data on the USB stick.