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Securing Connections
====================

By default, Airflow will save the passwords for the connection in plain text
within the metadata database. The ``crypto`` package is highly recommended
during installation. The ``crypto`` package does require that your operating
system has ``libffi-dev`` installed.

If ``crypto`` package was not installed initially, it means that your Fernet key in ``airflow.cfg`` is empty.

You can still enable encryption for passwords within connections by following below steps:

#. Install crypto package ``pip install 'apache-airflow[crypto]'``
#. Generate fernet_key, using this code snippet below. ``fernet_key`` must be a base64-encoded 32-byte key:

    .. code:: python

      from cryptography.fernet import Fernet
      fernet_key= Fernet.generate_key()
      print(fernet_key.decode()) # your fernet_key, keep it in secured place!

#. Replace ``airflow.cfg`` fernet_key value with the one from `Step 2`. *Alternatively,* you can store your fernet_key in OS environment variable - You do not need to change ``airflow.cfg`` in this case as Airflow will use environment variable over the value in ``airflow.cfg``:

    .. code-block:: bash

      # Note the double underscores
      export AIRFLOW__CORE__FERNET_KEY=your_fernet_key

#. Restart the webserver
#. For existing connections (the ones that you had defined before installing ``airflow[crypto]`` and creating a Fernet key), you need to open each connection in the connection admin UI, re-type the password, and save the change

Rotating encryption keys
========================

Once connection credentials and variables have been encrypted using a fernet
key, changing the key will cause decryption of existing credentials to fail. To
rotate the fernet key without invalidating existing encrypted values, prepend
the new key to the ``fernet_key`` setting, run
``airflow rotate_fernet_key``, and then drop the original key from
``fernet_keys``:

#. Set ``fernet_key`` to ``new_fernet_key,old_fernet_key``
#. Run ``airflow rotate_fernet_key`` to re-encrypt existing credentials with the new fernet key
#. Set ``fernet_key`` to ``new_fernet_key``