+# -*- coding: utf-8 -*-
+"""
+oauthlib.oauth2.rfc6749
+~~~~~~~~~~~~~~~~~~~~~~~
+
+This module is an implementation of various logic needed
+for consuming and providing OAuth 2.0 RFC6749.
+"""
+from __future__ import absolute_import, unicode_literals
+
+from .base import Client
+from ..parameters import prepare_token_request
+from ..parameters import parse_token_response
+
+
+class BackendApplicationClient(Client):
+
+ """A public client utilizing the client credentials grant workflow.
+
+ The client can request an access token using only its client
+ credentials (or other supported means of authentication) when the
+ client is requesting access to the protected resources under its
+ control, or those of another resource owner which has been previously
+ arranged with the authorization server (the method of which is beyond
+ the scope of this specification).
+
+ The client credentials grant type MUST only be used by confidential
+ clients.
+
+ Since the client authentication is used as the authorization grant,
+ no additional authorization request is needed.
+ """
+
+ def prepare_request_body(self, body='', scope=None, **kwargs):
+ """Add the client credentials to the request body.
+
+ The client makes a request to the token endpoint by adding the
+ following parameters using the "application/x-www-form-urlencoded"
+ format per `Appendix B`_ in the HTTP request entity-body:
+
+ :param scope: The scope of the access request as described by
+ `Section 3.3`_.
+ :param kwargs: Extra credentials to include in the token request.
+
+ The client MUST authenticate with the authorization server as
+ described in `Section 3.2.1`_.
+
+ The prepared body will include all provided credentials as well as
+ the ``grant_type`` parameter set to ``client_credentials``::
+
+ >>> from oauthlib.oauth2 import BackendApplicationClient
+ >>> client = BackendApplicationClient('your_id')
+ >>> client.prepare_request_body(scope=['hello', 'world'])
+ 'grant_type=client_credentials&scope=hello+world'
+
+ .. _`Appendix B`: http://tools.ietf.org/html/rfc6749#appendix-B
+ .. _`Section 3.3`: http://tools.ietf.org/html/rfc6749#section-3.3
+ .. _`Section 3.2.1`: http://tools.ietf.org/html/rfc6749#section-3.2.1
+ """
+ return prepare_token_request('client_credentials', body=body,
+ scope=scope, **kwargs)