foo.py

        if "HTTP_AUTHORIZATION" in self.request.META:
            authorization = self.request.META["HTTP_AUTHORIZATION"]
            auth_type, auth_value = authorization.split()[0:2]
            if auth_type.lower() == "basic":
                credentials = "%s:%s" % (self.client.key, self.client.secret)
                if auth_value != b64encode(credentials):
                    raise InvalidClient('Client authentication failed.')
            else:
                raise InvalidClient('Client authentication failed.')
        else:
            raise InvalidClient('Client authentication failed.')