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API Implicit Authentication with Python

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API Authentication with Python

I am working on an desktop inbox notifier for StackOverflow, using the API with Python.

The script I am working on first logs the user in on StackExchange, and then requests authorisation for the application.

Assuming the application has been authorised through web-browser interaction of the user. The application should be able to make requests to the API with authentication, hence it needs the access token specific to the user. This is done with the URL: https://stackexchange.com/oauth/dialog?client_id=54&scope=read_inbox&redirect_uri=https://stackexchange.com/oauth/login_success

When requesting authorisation via the web-browser the redirect is taking place and an access code is returned after a #. However, when requesting this same URL with Python (urllib2), no hash or key is returned in the response.

Why is this and how do I get it to work?

Here is my script (it's experimental) and remember: it assumes the user has already authorised the application.

#!/usr/bin/env python

import urllib
import urllib2
import cookielib
from BeautifulSoup import BeautifulSoup
from getpass import getpass    

# Define URLs
parameters = [ 'client_id=54',
               'scope=read_inbox',
               'redirect_uri=https://stackexchange.com/oauth/login_success'
             ]

dialog_url = 'https://stackexchange.com/oauth/dialog?' + '&'.join(parameters)
login_url = 'https://openid.stackexchange.com/account/login'
submit_url = 'https://openid.stackexchange.com/account/login/submit'
authentication_url = 'http://stackexchange.com/users/authenticate?openid_identifier='

# Set counter for requests:
counter = 0

# Build opener
jar = cookielib.CookieJar()
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(jar))


def authenticate(username='', password=''):

    '''
        Authenticates to StackExchange using user-provided username and password
    '''

    # Build up headers
    user_agent = 'Mozilla/5.0 (Ubuntu; X11; Linux i686; rv:8.0) Gecko/20100101 Firefox/8.0'
    headers = {'User-Agent' : user_agent}

    # Set Data to None
    data = None

    # 1. Build up URL request with headers and data    
    request = urllib2.Request(login_url, data, headers)
    response = opener.open(request)

    # Build up POST data for authentication
    html = response.read()
    fkey = BeautifulSoup(html).findAll(attrs={'name' : 'fkey'})[0].get('value').encode()

    values = {'email' : username,
              'password' : password,
              'fkey' : fkey}
    
    data = urllib.urlencode(values)
    
    # 2. Build up URL for authentication
    request = urllib2.Request(submit_url, data, headers)
    response = opener.open(request)
    

    # Check if logged in
    if response.url == 'https://openid.stackexchange.com/user':
        print ' Logged in! :) '
    else:
        print ' Login failed! :( '
    
    # Find user ID URL    
    html = response.read()
    id_url = BeautifulSoup(html).findAll('code')[0].text.split('"')[-2].encode()


    # 3. Build up URL for OpenID authentication
    data = None
    url = authentication_url + urllib.quote_plus(id_url)
    request = urllib2.Request(url, data, headers)
    response = opener.open(request)
    
    # 4. Build up URL request with headers and data
    request = urllib2.Request(dialog_url, data, headers)
    response = opener.open(request)
    
    if '#' in response.url:
        print 'Access code provided in URL.'
    else:
        print 'No access code provided in URL.'


if __name__ == '__main__':
    username = raw_input('Enter your username: ')
    password = getpass('Enter your password: ')
    authenticate(username, password)