Transport TLS Support

Whenever possible transports should provide TLS Support. Currently the :doc:tcp and :doc:ws transports support encryption and verification using TLS.

.. versionadded:: 2016.11.1

The TCP transport allows for the master/minion communication to be optionally wrapped in a TLS connection. Enabling this is simple, the master and minion need to be using the tcp connection, then the ssl option is enabled. The ssl option is passed as a dict and roughly corresponds to the options passed to the Python ssl.wrap_socket <https://docs.python.org/3/library/ssl.html#ssl.wrap_socket>_ function for backwards compatability.

.. versionadded:: 3007.0

The ssl option accepts verify_locations and verify_flags. The verify_locations option is a list of strings or dictionaries. Strings are passed as a single argument to the SSL context's load_verify_locations method. Dictionary keys are expected to be one of cafile, capath, cadata. For each corresponding key, the key and value will be passed as a keyword argument to load_verify_locations. The verify_flags option is a list of string names of verification flags which will be set on the SSL context. All paths are assumed to be the full path to the file or directory.

A simple setup looks like this, on the Salt Master add the ssl option to the master configuration file:

.. code-block:: yaml

ssl:
  keyfile: <path_to_keyfile>
  certfile: <path_to_certfile>

A more complex setup looks like this, on the Salt Master add the ssl option to the master's configuration file. In this example the Salt Master will require valid client side certificates from Minions by setting cert_reqs to CERT_REQUIRED. The Salt Master will also check a certificate revocation list if one is provided in verify_locations:

.. code-block:: yaml

ssl:
  keyfile: <path_to_keyfile>
  certfile: <path_to_certfile>
  cert_reqs: CERT_REQUIRED
  verify_locations:
    - <path_to_ca_cert>
    - capath: <directory_of_certs>
    - cafile: <path_to_crl>
  verify_flags:
    - VERIFY_CRL_CHECK_CHAIN

The minimal ssl option in the minion configuration file looks like this:

.. code-block:: yaml

ssl: True
# Versions below 2016.11.4:
ssl: {}

A Minion can be configured to present a client certificate to the master like this:

.. code-block:: yaml

ssl:
  keyfile: <path_to_keyfile>
  certfile: <path_to_certfile>

Specific options can be sent to the minion also, as defined in the Python ssl.wrap_socket function.