python - Google Cloud Endpoints 的自定义身份验证(而不是 OAuth2)

Question

我们对 App Engine 对 Google Cloud Endpoints 的支持感到非常兴奋.

也就是说我们还没有使用 OAuth2，通常使用用户名/密码来验证用户 这样我们就可以为没有 Google 帐户的客户提供支持。

我们希望将 API 迁移到 Google Cloud Endpoints，因为我们可以免费获得所有好处(API 控制台、客户端库、稳健性……)，但我们的主要问题是……

如何将自定义身份验证添加到我们之前在现有 API 中检查有效用户 session + CSRF token 的云端点。

有没有一种优雅的方法可以做到这一点，而无需在 protoRPC 消息中添加 session 信息和 CSRF token 之类的内容？

Answer 1

我正在为我的整个应用程序使用 webapp2 身份验证系统。所以我尝试将它重用于谷歌云身份验证，我明白了!

webapp2_extras.auth 使用 webapp2_extras.sessions 来存储身份验证信息。这个 session 可以以 3 种不同的格式存储:securecookie、datastore 或 memcache。

Securecookie 是我正在使用的默认格式。我认为它足够安全，因为 webapp2 身份验证系统用于在生产环境中运行的许多 GAE 应用程序。

所以我解码了这个securecookie并从GAE端点重用它。我不知道这是否会产生一些安全问题(我希望不会)但也许@bossylobster 可以说看看安全方面是否可以。

我的 API:

import Cookie
import logging
import endpoints
import os
from google.appengine.ext import ndb
from protorpc import remote
import time
from webapp2_extras.sessions import SessionDict
from web.frankcrm_api_messages import IdContactMsg, FullContactMsg, ContactList, SimpleResponseMsg
from web.models import Contact, User
from webapp2_extras import sessions, securecookie, auth
import config

__author__ = 'Douglas S. Correa'

TOKEN_CONFIG = {
    'token_max_age': 86400 * 7 * 3,
    'token_new_age': 86400,
    'token_cache_age': 3600,
}

SESSION_ATTRIBUTES = ['user_id', 'remember',
                      'token', 'token_ts', 'cache_ts']

SESSION_SECRET_KEY = '9C3155EFEEB9D9A66A22EDC16AEDA'


@endpoints.api(name='frank', version='v1',
               description='FrankCRM API')
class FrankApi(remote.Service):
    user = None
    token = None

    @classmethod
    def get_user_from_cookie(cls):
        serializer = securecookie.SecureCookieSerializer(SESSION_SECRET_KEY)
        cookie_string = os.environ.get('HTTP_COOKIE')
        cookie = Cookie.SimpleCookie()
        cookie.load(cookie_string)
        session = cookie['session'].value
        session_name = cookie['session_name'].value
        session_name_data = serializer.deserialize('session_name', session_name)
        session_dict = SessionDict(cls, data=session_name_data, new=False)

        if session_dict:
            session_final = dict(zip(SESSION_ATTRIBUTES, session_dict.get('_user')))
            _user, _token = cls.validate_token(session_final.get('user_id'), session_final.get('token'),
                                               token_ts=session_final.get('token_ts'))
            cls.user = _user
            cls.token = _token

    @classmethod
    def user_to_dict(cls, user):
        """Returns a dictionary based on a user object.

        Extra attributes to be retrieved must be set in this module's
        configuration.

        :param user:
            User object: an instance the custom user model.
        :returns:
            A dictionary with user data.
        """
        if not user:
            return None

        user_dict = dict((a, getattr(user, a)) for a in [])
        user_dict['user_id'] = user.get_id()
        return user_dict

    @classmethod
    def get_user_by_auth_token(cls, user_id, token):
        """Returns a user dict based on user_id and auth token.

        :param user_id:
            User id.
        :param token:
            Authentication token.
        :returns:
            A tuple ``(user_dict, token_timestamp)``. Both values can be None.
            The token timestamp will be None if the user is invalid or it
            is valid but the token requires renewal.
        """
        user, ts = User.get_by_auth_token(user_id, token)
        return cls.user_to_dict(user), ts

    @classmethod
    def validate_token(cls, user_id, token, token_ts=None):
        """Validates a token.

        Tokens are random strings used to authenticate temporarily. They are
        used to validate sessions or service requests.

        :param user_id:
            User id.
        :param token:
            Token to be checked.
        :param token_ts:
            Optional token timestamp used to pre-validate the token age.
        :returns:
            A tuple ``(user_dict, token)``.
        """
        now = int(time.time())
        delete = token_ts and ((now - token_ts) > TOKEN_CONFIG['token_max_age'])
        create = False

        if not delete:
            # Try to fetch the user.
            user, ts = cls.get_user_by_auth_token(user_id, token)
            if user:
                # Now validate the real timestamp.
                delete = (now - ts) > TOKEN_CONFIG['token_max_age']
                create = (now - ts) > TOKEN_CONFIG['token_new_age']

        if delete or create or not user:
            if delete or create:
                # Delete token from db.
                User.delete_auth_token(user_id, token)

                if delete:
                    user = None

            token = None

        return user, token

    @endpoints.method(IdContactMsg, ContactList,
                      path='contact/list', http_method='GET',
                      name='contact.list')
    def list_contacts(self, request):

        self.get_user_from_cookie()

        if not self.user:
            raise endpoints.UnauthorizedException('Invalid token.')

        model_list = Contact.query().fetch(20)
        contact_list = []
        for contact in model_list:
            contact_list.append(contact.to_full_contact_message())

        return ContactList(contact_list=contact_list)

    @endpoints.method(FullContactMsg, IdContactMsg,
                      path='contact/add', http_method='POST',
                      name='contact.add')
    def add_contact(self, request):
        self.get_user_from_cookie()

        if not self.user:
           raise endpoints.UnauthorizedException('Invalid token.')


        new_contact = Contact.put_from_message(request)

        logging.info(new_contact.key.id())

        return IdContactMsg(id=new_contact.key.id())

    @endpoints.method(FullContactMsg, IdContactMsg,
                      path='contact/update', http_method='POST',
                      name='contact.update')
    def update_contact(self, request):
        self.get_user_from_cookie()

        if not self.user:
           raise endpoints.UnauthorizedException('Invalid token.')


        new_contact = Contact.put_from_message(request)

        logging.info(new_contact.key.id())

        return IdContactMsg(id=new_contact.key.id())

    @endpoints.method(IdContactMsg, SimpleResponseMsg,
                      path='contact/delete', http_method='POST',
                      name='contact.delete')
    def delete_contact(self, request):
        self.get_user_from_cookie()

        if not self.user:
           raise endpoints.UnauthorizedException('Invalid token.')


        if request.id:
            contact_to_delete_key = ndb.Key(Contact, request.id)
            if contact_to_delete_key.get():
                contact_to_delete_key.delete()
                return SimpleResponseMsg(success=True)

        return SimpleResponseMsg(success=False)


APPLICATION = endpoints.api_server([FrankApi],
                                   restricted=False)