oauth google using python

Question

i am fairly new to programming for web. and i want to start from scratch here. i tried to search the net but ended up completely confused. now what i want to learn is how to authenticate a google account through a python script. can anyone please provide me with a code fragment or any example.

thanks a lot in advance.

Answer 1

I spent a whole day on coding this, after several failed attempts over the past few weeks. This only gets you as far as the first step, but it does so without any external libraries. And yes, I know it's close to two years after the OP, but from what I could see it still needed to be done.

#!/usr/bin/python
'demo Google OAuth'
import sys, os, urllib, urllib2, time, httplib
import hmac, hashlib, random, re, base64
PARAMETERS = {
 'oauth_consumer_key': os.getenv('OAUTH_CONSUMER_KEY') or 'anonymous',
 'oauth_signature_method': 'HMAC-SHA1',
 'oauth_signature': '',
 'oauth_timestamp': os.getenv('OAUTH_TIMESTAMP') or '%d' % time.time(),
 'oauth_nonce': os.getenv('OAUTH_NONCE') or '%x' % random.getrandbits(64),
 'oauth_version': '1.0',
 'oauth_callback': os.getenv('OAUTH_CALLBACK') or 'callback',
}
SCOPE = {'scope': 'https://www.google.com/calendar/feeds/'}
SECRET = os.getenv('OAUTH_CONSUMER_SECRET') or 'anonymous'
def google_oauth():
 'OAuthGetRequestToken, OAuthAuthorizeToken, OAuthGetAccessToken'
 request_token = get_request_token()
 return request_token
def get_request_token():
 'ask Google for a request token'
 url = 'https://www.google.com/accounts/OAuthGetRequestToken'
 token_secret = ''  # we don't have a token secret yet
 PARAMETERS['oauth_signature'] = sign('&'.join((SECRET, token_secret)),
  '&'.join(map(urlencode, ('GET', url, parameters('signing')))))
 body = urllib.urlencode(SCOPE)
 request = urllib2.Request(url + '?' + body)
 request.add_header('Authorization', 'OAuth ' + parameters('header'))
 opener = urllib2.build_opener(urllib2.HTTPSHandler(debuglevel = 1))
 response = opener.open(request)
 reply = response.read()
 response.close()
 return reply
def byte_encode(match):
 'for use with re.sub'
 return '%%%02X' % ord(match.group())
def urlencode(string):
 "unreserved = ALPHA, DIGIT, '-', '.', '_', '~'"
 return re.sub(re.compile('[^0-9A-Za-z._~-]'),
  byte_encode, string.encode('utf8'))
def sign(secret, text):
 print >>sys.stderr, 'signature base string: "%s", secret: %s' % (
  repr(text), repr(secret))
 digest = hmac.new(secret, text, hashlib.sha1).digest()
 return urlencode(base64.encodestring(digest).rstrip())
def base64string(hexstring):
 recoded = urlencode(base64.encodestring(hexstring.decode('hex')).rstrip())
 print >>sys.stderr, 'recoded:', recoded
 return recoded
def parameters(format):
 if format == 'header':
  formatted = ', '.join(['%s="%s"' % (key, value)
   for key, value in PARAMETERS.items()])
 elif format == 'signing':
  formatted = '&'.join(sorted(['%s=%s' % (key,
   urlencode(value.encode('utf8'))) for
   key, value in (PARAMETERS.items() + SCOPE.items()) if
   key not in ['oauth_signature']]))
 #print >>sys.stderr, format, formatted
 return formatted
def hmac_sha1_test():
 'from tools.ietf.org/html/rfc2202'
 assert sign('\x0b' * 20, 'Hi There') == base64string(
  'b617318655057264e28bc0b6fb378c8ef146be00')
 assert sign('Jefe', 'what do ya want for nothing?') == base64string(
  'effcdf6ae5eb2fa2d27416d5f184df9c259a7c79')
 assert sign('\xaa' * 20, '\xdd' * 50) == base64string(
  '125d7342b9ac11cd91a39af48aa17b4f63f175d3')
 # last test from http://oauth.net/core/1.0/#rfc.section.9.1.1, app. A.5.2
 assert sign('kd94hf93k423kf44&pfkkdhi9sl3r4s00',
  'GET&http%3A%2F%2Fphotos.example.net%2Fphotos&file%3Dvacation.jpg%26' + \
  'oauth_consumer_key%3Ddpf43f3p2l4k3l03%26oauth_nonce%3D' + \
  'kllo9940pd9333jh%26oauth_signature_method%3DHMAC-SHA1%26' + \
  'oauth_timestamp%3D1191242096%26oauth_token%3Dnnch734d00sl2jdk%26' + \
  'oauth_version%3D1.0%26size%3Doriginal') == urlencode(
   'tR3+Ty81lMeYAr/Fid0kMTYa/WM=')
 return True
if __name__ == '__main__':
 command = os.path.splitext(os.path.basename(sys.argv[0]))[0]
 print eval(command)(*sys.argv[1:])

Save it as google_oauth.py, and you can link to it like so:

ln -s google_oauth.py hmac_sha1_test.py

to test any of the subroutines. Combined with the use of environment variables, you can compare your results with those of Google's OAuth Playground (other folks here provided the link) and see where you are going wrong. I found many problems with the script that way; there may well be many more. But if you invoke ./google_oauth.py, you should see something like this:

jcomeau@intrepid:~/rentacoder/marchie$ ./google_oauth.py 
signature base string: "'GET&https%3A%2F%2Fwww.google.com%2Faccounts%2FOAuthGetRequestToken&oauth_callback%3Dcallback%26oauth_consumer_key%3Danonymous%26oauth_nonce%3Da64720fda018906b%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D1302253695%26oauth_version%3D1.0%26scope%3Dhttps%253A%252F%252Fwww.google.com%252Fcalendar%252Ffeeds%252F'", secret: 'anonymous&'
send: 'GET /accounts/OAuthGetRequestToken?scope=https%3A%2F%2Fwww.google.com%2Fcalendar%2Ffeeds%2F HTTP/1.1\r\nAccept-Encoding: identity\r\nHost: www.google.com\r\nConnection: close\r\nAuthorization: OAuth oauth_nonce="a64720fda018906b", oauth_timestamp="1302253695", oauth_consumer_key="anonymous", oauth_signature_method="HMAC-SHA1", oauth_version="1.0", oauth_signature="LSJxopFXWN71sTSIBIkNeGgsOjc%3D", oauth_callback="callback"\r\nUser-Agent: Python-urllib/2.6\r\n\r\n'
reply: 'HTTP/1.1 200 OK\r\n'
header: Content-Type: text/plain; charset=UTF-8
header: Date: Fri, 08 Apr 2011 09:08:20 GMT
header: Expires: Fri, 08 Apr 2011 09:08:20 GMT
header: Cache-Control: private, max-age=0
header: X-Content-Type-Options: nosniff
header: X-XSS-Protection: 1; mode=block
header: Content-Length: 118
header: Server: GSE
header: Connection: close
oauth_token=4%2FfvSIWW9WBHXa_CjInpOf4FdNYhCj&oauth_token_secret=qhB1EGIKjL1pG9POF2ZOcQk3&oauth_callback_confirmed=true

Answer 2

Some good links above (the playground is invaluable).

I use a mixture of Leah Culver's oAuth code (the example in b3rx's post) and FireEagle's Python OAuth code. The former, the last time I looked, was lacking scope methods.

Also, make sure you are clear on whether you are using 2 or 3 legged OAuth:

Answer 3

Good intro: http://code.google.com/apis/accounts/docs/OAuth.html

Great working, playable example: http://googlecodesamples.com/oauth_playground/

Answer 4

See the document on Google Data API docs:

• Getting Started with the Google Data Python Library

There's a ClientLogin sample under "Hello World".

Answer 5

try this example