Flask-Sentinel 0.0.8
OAuth2 Provider for Flask applications.
License: BSD

Flask-Sentinel
==============
OAuth2 Provider currently supporting the Resource Owner Password Credentials
Grant as described in Section 1.3.3 of `RFC 6749`_.

Powered by Flask-OAuthlib, Redis and MongoDB.

Deployment
----------

.. code-block:: console

    $ pip install flask-sentinel

Usage
-----
Once the extension and its dependencies are installed, you can use it like any
other Flask extension:

.. code-block:: python

    from flask import Flask
    from flask.ext.sentinel import ResourceOwnerPasswordCredentials, oauth


    app = Flask(__name__)

    # optionally load settings from py module
    app.config.from_object('settings')

    @app.route('/endpoint')
    @oauth.require_oauth()
    def restricted_access():
        return "You made it through and accessed the protected resource!"

    if __name__ == '__main__':
        ResourceOwnerPasswordCredentials(app)
        app.run(ssl_context='adhoc')

User and Client Management
--------------------------
You can create users and clients through the default management interface
available at ``https://localhost:5000/oauth/management``.

.. image:: https://raw.githubusercontent.com/pyeve/flask-sentinel/master/static/console.png
   :scale: 25 %

You can override the default page above with your own. Just drop your custom
``management.html`` file in a ``templates`` folder residing in your application
root.

This page can and should have restricted access. In order to achieve that, set
``SENTINEL_MANAGEMENT_USERNAME`` and ``SENTINEL_MANAGEMENT_PASSWORD`` in your
application settings. This will fire up a Basic Auth dialog when the page is
accessed with a browser.

Testing
-------
After creating a user and client, you may use ``curl`` to test the application.

Generating a Bearer Token
~~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: console

    $ curl -k -X POST -d "client_id=9qFbZD4udTzFVYo0u5UzkZX9iuzbdcJDRAquTfRk&grant_type=password&username=jonas&password=pass" https://localhost:5000/oauth/token
    {"access_token": "NYODXSR8KalTPnWUib47t5E8Pi8mo4", "token_type": "Bearer", "refresh_token": "s6L6OPL2bnKSRSbgQM3g0wbFkJB4ML", "scope": ""}

Generating a Bearer Token Using a Retrieved Refresh Token
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: console

    $ curl -X POST -d "client_id=9qFbZD4udTzFVYo0u5UzkZX9iuzbdcJDRAquTfRk&grant_type=refresh_token&refresh_token=s6L6OPL2bnKSRSbgQM3g0wbFkJB4ML" https://localhost:5000/oauth/token
    {"access_token": "RmPAfqfsDoMCbQ2DUUehwcw1hMCMJj", "token_type": "Bearer", "expires_in": 3600, "refresh_token": "s6L6OPL2bnKSRSbgQM3g0wbFkJB4ML", "scope": ""}

Accessing a Protected Resource Using Retrieved Bearer Token
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: console

    $ curl -k -H "Authorization: Bearer NYODXSR8KalTPnWUib47t5E8Pi8mo4" https://localhost:5000/endpoint
    You made it through and accessed the protected resource!


Configuration
-------------
Configuration works like any other `Flask configuration`_. Here are
the built-in defaults:

======================================= ======================================
``SENTINEL_ROUTE_PREFIX``               Default prefix for OAuth endpoints.
                                        Defaults to ``/oauth``. Prepends both
                                        token and management urls.

``SENTINEL_TOKEN_URL``                  Url for token creation endpoint. Set to
                                        ``False`` to disable this feature.
                                        Defaults to ``/token``, so the
                                        complete url is ``/oauth/token``.

``SENTINEL_MANAGEMENT_URL``             Url for management endpoint. Set to
                                        ``False`` to disable this feature.
                                        Defaults to ``/management``, so the
                                        complete url is ``/oauth/management``.

``SENTINEL_REDIS_URL``                  Url for the redis server. Defaults to
                                        ``redis://localhost:6379/0``.

``SENTINEL_MONGO_DBNAME``               Mongo database name. Defaults to
                                        ``oauth``.

``SENTINEL_MANAGEMENT_USERNAME``        Username needed to access the
                                        management page.

``SENTINEL_MANAGEMENT_PASSWORD``        Password needed to access the
                                        management page.

``OAUTH2_PROVIDER_ERROR_URI``           The error page when there is an error,
                                        default value is ``/oauth/errors``.

``OAUTH2_PROVIDER_TOKEN_EXPIRES_IN``    Default Bearer token expires time,
                                        default is ``3600``.

``OAUTH2_PROVIDER_ERROR_ENDPOINT``      You can also configure the error page
                                        uri with an endpoint name.

======================================= ======================================

Other standard PyMongo settings such as ``MONGO_HOST``, ``MONGO_PORT``,
``MONGO_URI`` are also supported; just prefix them with ``SENTINEL_`` as
seen above.

When a token is created it is added to both the database and the Redis cache.
In Redis, ``key`` is the access token itself while ``value`` is the id of the
user who requested the token. This allows for fast token
authentication/verification bypassing the database lookup. This tecnique can be
used, for example, when integrating ``flask-sentinel`` with `Eve`_ powered REST
API instances.

Using Flask-Sentinel with Eve
-----------------------------
See the `Eve-OAuth2`_ example project.

Security
--------
SSL/TLS
~~~~~~~
When working with OAuth 2.0, all communications must be encrypted with SSL/TLS.
This example uses auto-generated SSL certificates, however in a production
environment you should use a more formal, widely trusted certificate associated
with your domain. In addition, requests should be handled by something like
NGINX and proxied to the authentication service.

*Note: Add `-k` to your `curl` arguments if you are working with an untrusted
development server running under SSL/TLS.*

Password Hashing
~~~~~~~~~~~~~~~~
Bcrypt and a randomly generated salt are used to hash each user password before
it is added to the database. You should never store passwords in plain text!

License
-------
Flask-Sentinel is a `Nicola Iarocci`_ and `Gestionali Amica`_ open source
project distributed under the `BSD license`_.

Acknowledgement
---------------
This work is based on the `yoloAPI`_ project by `Josh Brandoff`_ and `Jonas
Brunsgaard`_.

.. _`RFC 6749`: http://tools.ietf.org/html/rfc6749#section-1.3.3
.. _`yoloAPI`: https://github.com/brunsgaard/yoloAPI
.. _`Josh Brandoff`: https://github.com/EmergentBehavior
.. _`Jonas Brunsgaard`: https://github.com/brunsgaard
.. _`Nicola Iarocci`: http://nicolaiarocci.com
.. _`Gestionali Amica`: http://gestionaleamica.com
.. _`BSD license`: https://github.com/pyeve/flask-sentinel/blob/master/LICENSE
.. _`Eve-OAuth2`: https://github.com/pyeve/eve-oauth2
.. _`Eve`: http://python-eve.org
.. _`Flask configuration`: http://flask.pocoo.org/docs/0.10/config/