Add encryption for backups

[tkhduracell]

Would adding encryption be useful?

I have an internal fork of this repo that also adds encryption. This basically add a ENCRYPTION_KEY var that you point to a key file.

ENCRYPTION_KEY: Use AES encryption to protect the uploaded file.

Cons:

• Needs openssl to be installed in Dockerfile

Basically it adds yet another step in the backup process.

def encrypt_backup():
    out = backup_file + '.aes'
    cmd("openssl aes-256-cbc -md sha512 -pbkdf2 -iter 100000 -salt -in %s -out %s -pass file:%s" % (
        backup_file, out, ENCRYPTION_KEY
    ))
    return out