Complete implementation of OAuth2 (the hard version) in about 10 lines of code

oauth2-is-pretty-good.py

from google.appengine.ext import webapp
from google.appengine.ext.webapp import util
from google.appengine.api import urlfetch
from django.utils import simplejson as json
import urllib

OAUTH_CLIENT_ID = "1027534278801.apps.googleusercontent.com"
OAUTH_CLIENT_SECRET = "X0ezwreyuXIzNx9vDUkUYmDZ"

class MainHandler(webapp.RequestHandler):
    def get(self):
      params = urllib.urlencode({
        "response_type": "code",
        "redirect_uri": "http://localhost:8081/oa2cb",
        "client_id":OAUTH_CLIENT_ID,
        "scope":"https://www.googleapis.com/auth/buzz"
      })
      url = "https://www.google.com/accounts/o8/oauth2/authorization?%s" % params
      self.response.out.write('<a href="%s">oauth!</a>' % url)

class OAuthHandler(webapp.RequestHandler):
  def get(self):
    payload = urllib.urlencode({
      "code": self.request.get('code'),
      "grant_type": "authorization_code",
      "redirect_uri": "http://localhost:8081/oa2cb",
      "client_id":OAUTH_CLIENT_ID,
      "client_secret":OAUTH_CLIENT_SECRET
    })
    
    url = "https://www.google.com/accounts/o8/oauth2/token"
    res_str = urlfetch.fetch(url, payload=payload, method=urlfetch.POST)
    obj = json.loads(res_str.content)
    access = obj["access_token"]
    self.response.out.write(obj)


def main():
    application = webapp.WSGIApplication([('/', MainHandler),
                                        ('/oa2cb', OAuthHandler)],
                                         debug=True)
    util.run_wsgi_app(application)


if __name__ == '__main__':
    main()