[SOLVED] OAuth2 with python gdata

Some time ago I wrote an app in python that uses Google's python gdata api. I started following the gdata_api example, and it worked alright. At some point google turned off uid/pwd authentication, and enforced OAuth2. So i modified the app to run with OAuth2.

It has worked fine for a few years, until some day it stopped, and began to return error 400 (= bad request) when trying to request the access token (the one that comes from https://www.googleapis.com/oauth2/v3/token , to be clear). This doesn't happen the first time (meaning right after one requests a new authorization token, and uses it for the first time), but every time after that.

I have seen posts saying that they fixed the redirect uri, and then they got it working, but they didn't write what to use. I also don't know whether it would be the proper fix. The stripped down version of my OAuth2 implementation is the following (and, i repeat, it has worked alright for years):

import sys
import os

# WARNING!! you need also TLSLITE inside gdata/oauth subdir.
# This is how supported google shits are nowadays.
# See: https://github.com/google/gdata-python-client/issues/44

sys.path.append("~/gdatalib/gdata-python-client-master/src") #Quick and dirty way to get the latest version in. It doesnt make much of a difference anyway

import gdata
import gdata.contacts.data
import gdata.contacts.client
import urllib
import urllib2
import json
import subprocess

clientId = ""  # your app's client ID  , get one at https://console.developers.google.com/projectselector/apis/credentials?supportedpurview=project
clientSecret = "" # your app's client secret
oauthPath = ""
userAgent = "fuBar"

class OAuth2Auth(object):
    def __init__(self, sUserName, sAccountPassword):
        #gather all data
        self.username           = sUserName.split("@")[0] # remove @whatever, if any
        self.password           = sAccountPassword
        self.clientid           = clientId
        self.clientsecret       = clientSecret
        self.rediruri           = '''urn:ietf:wg:oauth:2.0:oob'''

        self.authrequesturl     = ("https://accounts.google.com/o/oauth2/auth?scope=https://www.google.com/m8/feeds/"
                                  "&redirect_uri=%s"
                                  "&response_type=code"
                                  "&client_id=%s"
                                  "&login_hint=%s") # % (redir_uri,client_id,sAccountName+"@gmail.com")
        self.oauth2_endpoint    = "https://www.googleapis.com/oauth2/v3/token"



        self.tokensPath         = os.path.join(oauthPath, self.username)
        #print self.tokensPathata should be a b
        self.accessToken        = None
        self.refreshToken       = None

        self._getTokens()
        #create an OAuth2Token
        print "Creating Oauth2Token...",
        self.oauth2token = gdata.gauth.OAuth2Token(client_id = self.clientid,
                                          client_secret = self.clientsecret,
                                          scope = 'https://www.google.com/m8/feeds/',
                                          user_agent = userAgent,
                                          access_token = self.accessToken,
                                          refresh_token = self.refreshToken)
        print " done."
        pass

    def __del__(self):
        #check that the access token in the OAuth2Token is the same as the read one.
        if (self.accessToken != self.oauth2token.access_token):
            #if not, update the file
            print "Access token has been updated by gdata_api. Updating the storage."
            self.accessToken = self.oauth2token.access_token
            self._storeTokens()
        pass

    def _storeTokens(self):
        if self.accessToken and self.refreshToken:
            f= open(self.tokensPath,'w+');
            f.seek(0);
            f.truncate();
            data = [ self.accessToken + '\n', self.refreshToken+'\n' ]
            f.writelines(data)
            f.close()

    def _readTokens(self):
        if not os.path.isfile(self.tokensPath):
            raise Exception('Expecting to find token file, but the file is not present!')

        f= open(self.tokensPath,'r')
        tokenlist = [ l.rstrip('\n') for l in f.readlines() ]
        f.close()

        if ( len(tokenlist) < 2 ):
            raise Exception('Not enough data in token file!')

        self.accessToken        = tokenlist[0]
        self.refreshToken       = tokenlist[1]


    def _getTokens(self):
        if not os.path.isfile(self.tokensPath):
            print "TokenPath doesn't exist. requesting new tokens"
            self._requestNewTokens()
            self._storeTokens()
        else:
            print "TokenPath exists"
        self._readTokens()


    def _requestNewTokens(self):
        #print '\nSTEP 1: Create OAuth2 request token URL.'
        request_url = self.authrequesturl % (self.rediruri,self.clientid,self.username+"@gmail.com")

        #print '\nSTEP 2: Spawn grob with adequate URL.'

        CHROME = os.path.join('C:\\', 'Program Files (x86)', 'Google', 'Chrome', 'Application', 'chrome.exe')
        CHROME = "/usr/bin/google-chrome" # for linux
        #CHROME = "" # or use whatever browser
        #subprocess.call([CHROME, '--incognito', request_url])   #use this the first time, after, you can also hardcode the token below
        request_token = """<your request token here to avoid storing and retrieving it>""" # You can hardcode the token here, if you got, and comment the line above spawning a chrome

        #print 'Request Token fetched: %s' % request_token
        #print '\nSTEP 3: Exchange auth token for access and refresh OAuth2 tokens.'


        request_args = { 'code':request_token, 
                         'client_id': self.clientid , 
                         'client_secret': self.clientsecret,
                         'redirect_uri':self.rediruri,
                         'grant_type':'authorization_code' }

        data = urllib.urlencode(request_args)
        fullUrl = self.oauth2_endpoint + "/" + data
        request = urllib2.Request(self.oauth2_endpoint, data)

        try:
            response = urllib2.urlopen(request)  # ===== FAILS HERE =====
            json_data = response.read()
            parsed_json = json.loads(json_data)
            self.accessToken = parsed_json['access_token']
            self.refreshToken =parsed_json['refresh_token']
            print parsed_json
        except Exception, e:
            print fullUrl
            print request.get_full_url()
            print request.get_selector()
            print e


def main():
    testuser="someuser@gmail.com"
    testpass="somepass"
    manager = OAuth2Auth(testuser,testpass)


if __name__ == '__main__':
    main()

According to https://developers.google.com/identity/protocols/OAuth2WebServer#offline, one should add access_type = "offline" in requesting the access token, to also get a refresh token. However, i tried this and it doesn't work.

OAuth2 with python gdata_api : 400 Bad request