mongoauthplugin.py

import asyncio
from bson import ObjectId

class MongoAuthPlugin(BaseAuthPlugin):

    def __init__(self, context):
        super().__init__(context)
        self._db = db

    @asyncio.coroutine
    def authenticate(self, *args, **kwargs):
        authenticated = super().authenticate(*args, **kwargs)

        if authenticated:
            session = kwargs.get('session', None)
            if session.username:
                user = yield from self._db.users.find_one({"_id": ObjectId(session.username)})
                if not user:
                    authenticated = False
                    self.context.logger.debug(
                        "No hash found for user '%s'" % session.username)
                else:
                    authenticated = yield from self._db.users.find_one({"_id": ObjectId(session.username), "secret": session.password})
            else:
                return None
        return authenticated