Source code for oauth_dropins.github

"""GitHub OAuth drop-in.

API docs:
https://developer.github.com/v4/
https://developer.github.com/apps/building-oauth-apps/authorization-options-for-oauth-apps/#web-application-flow
"""
import json
import logging
import urllib
import urlparse

import appengine_config
import handlers
from models import BaseAuth
from webutil import util

from google.appengine.ext import ndb
from webob import exc

# URL templates. Can't (easily) use urlencode() because I want to keep
# the %(...)s placeholders as is and fill them in later in code.
GET_AUTH_CODE_URL = str('&'.join((
    'https://github.com/login/oauth/authorize?'
    'client_id=%(client_id)s',
    # https://developer.github.com/apps/building-oauth-apps/scopes-for-oauth-apps/
    'scope=%(scope)s',
    # if provided, must be the same in the access token request, or a subpath!
    'redirect_uri=%(redirect_uri)s',
    'state=%(state)s',
    )))

GET_ACCESS_TOKEN_URL = 'https://github.com/login/oauth/access_token'

API_GRAPHQL = 'https://api.github.com/graphql'
# https://developer.github.com/v4/object/user/
GRAPHQL_USER = {
  'query': """
query {
  viewer {
    id
    login
    name
    url
    avatarUrl
    id
    location
    websiteUrl
    bio
  }
}""",
}


[docs]class GitHubAuth(BaseAuth): """An authenticated GitHub user. Provides methods that return information about this user and make OAuth-signed requests to the GitHub REST API. Stores OAuth credentials in the datastore. See models.BaseAuth for usage details. GitHub-specific details: implements get() but not urlopen(), http(), or api(). The key name is the username. """ access_token_str = ndb.StringProperty(required=True) user_json = ndb.TextProperty()
[docs] def site_name(self): return 'GitHub'
[docs] def user_display_name(self): """Returns the user's full name or username. """ return self.key.string_id()
[docs] def access_token(self): """Returns the OAuth access token string. """ return self.access_token_str
[docs] def get(self, *args, **kwargs): """Wraps requests.get() and adds the Bearer token header. TODO: unify with medium.py. """ return self._requests_call(util.requests_get, *args, **kwargs)
[docs] def post(self, *args, **kwargs): """Wraps requests.post() and adds the Bearer token header. TODO: unify with medium.py. """ return self._requests_call(util.requests_post, *args, **kwargs)
def _requests_call(self, fn, *args, **kwargs): headers = kwargs.setdefault('headers', {}) headers['Authorization'] = 'Bearer ' + self.access_token_str resp = fn(*args, **kwargs) assert 'errors' not in resp, resp try: resp.raise_for_status() except BaseException, e: util.interpret_http_exception(e) raise return resp
[docs]class StartHandler(handlers.StartHandler): """Starts GitHub auth. Requests an auth code and expects a redirect back. """ DEFAULT_SCOPE = ''
[docs] def redirect_url(self, state=None): assert (appengine_config.GITHUB_CLIENT_ID and appengine_config.GITHUB_CLIENT_SECRET), ( "Please fill in the github_client_id and " "github_client_secret files in your app's root directory.") return str(GET_AUTH_CODE_URL % { 'client_id': appengine_config.GITHUB_CLIENT_ID, 'redirect_uri': urllib.quote_plus(self.to_url()), # TODO: does GitHub require non-empty state? 'state': urllib.quote_plus(state if state else ''), 'scope': self.scope, })
[docs]class CallbackHandler(handlers.CallbackHandler): """The OAuth callback. Fetches an access token and stores it. """ def get(self): # handle errors error = self.request.get('error') if error: if error == 'access_denied': logging.info('User declined') self.finish(None, state=self.request.get('state')) return else: msg = 'Error: %s: %s' % (error, self.request.get('error_description')) logging.info(msg) raise exc.HTTPBadRequest(msg) # extract auth code and request access token auth_code = util.get_required_param(self, 'code') data = { 'code': auth_code, 'client_id': appengine_config.GITHUB_CLIENT_ID, 'client_secret': appengine_config.GITHUB_CLIENT_SECRET, # redirect_uri here must be the same in the oauth code request! # (the value here doesn't actually matter since it's requested server side.) 'redirect_uri': self.request.path_url, } resp = util.requests_post(GET_ACCESS_TOKEN_URL, data=urllib.urlencode(data)).text logging.debug('Access token response: %s', resp) resp = urlparse.parse_qs(resp) error = resp.get('error') if error: msg = 'Error: %s: %s' % (error[0], resp.get('error_description')) logging.info(msg) raise exc.HTTPBadRequest(msg) access_token = resp['access_token'][0] resp = GitHubAuth(access_token_str=access_token).post( API_GRAPHQL, json=GRAPHQL_USER).json() logging.debug('GraphQL data.viewer response: %s', resp) user_json = resp['data']['viewer'] auth = GitHubAuth(id=user_json['login'], access_token_str=access_token, user_json=json.dumps(user_json)) auth.put() self.finish(auth, state=self.request.get('state'))