Introduction
============

`Diffie-Hellman Key Exchange`_ is a way to securely share encryption keys
publicly between two parties. It's used in TLS and SSL connections to provide
`Perfect Forward Secrecy`_. Unfortunately, the default DH parameters distributed
with applications are susceptible to a `downgrade attack`_.

The ``debops.dhparam`` Ansible role will generate a set of strong
Diffie-Hellman parameters on the Ansible Controller, which will be preseeded on
remote hosts, and will be ready to use by other applications. A separate script
can then be used on remote hosts in the background to generate new random DH
parameters, either once or in regular intervals.

.. _Diffie-Hellman Key Exchange: https://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange
.. _Perfect Forward Secrecy: https://en.wikipedia.org/wiki/Forward_secrecy
.. _downgrade attack: https://weakdh.org/

Installation
~~~~~~~~~~~~

This role requires at least Ansible ``v1.9.0``. To install it, run::

    ansible-galaxy install debops.dhparam

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