Python cloud print authorization

Question

I'm trying to use Google's app api to authorize my python program to query google-cloud-print queues. I'm using all of the information from https://developers.google.com/cloud-print/docs/pythonCode. After including my login, password, and client-id I made from the cloud app in google. I still get 404 errors. The Gaia method returns nothing in the token dictionary. Has anyone had experience with this? or with using their new OAuth2 system? I can't seem to find anything on google about this problem.

Here is my program with my login details redacted.

import base64
import httplib
import sys
import os
import time
import logging
import mimetools
import urllib
import urllib2
import optparse
import string
import ConfigParser
import json

CRLF = '\r\n'
BOUNDARY = mimetools.choose_boundary()

# The following are used for authentication functions.
FOLLOWUP_HOST = 'www.google.com/cloudprint'
FOLLOWUP_URI = 'select%2Fgaiaauth'
GAIA_HOST = 'www.google.com'
LOGIN_URI = '/accounts/ServiceLoginAuth'
LOGIN_URL = 'https://www.google.com/accounts/ClientLogin'
SERVICE = 'cloudprint'
OAUTH = '175351968146.apps.googleusercontent.com'

# The following are used for general backend access.
CLOUDPRINT_URL = 'http://www.google.com/cloudprint'
# CLIENT_NAME should be some string identifier for the client you are writing.
CLIENT_NAME = 'google-cloud-print'

# The following object is used in the sample code, but is not necessary.
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)




def EncodeMultiPart(fields, files, file_type='application/xml'):
    """Encodes list of parameters and files for HTTP multipart format.

    Args:
      fields: list of tuples containing name and value of parameters.
      files: list of tuples containing param name, filename, and file contents.
      file_type: string if file type different than application/xml.
    Returns:
      A string to be sent as data for the HTTP post request.
    """
    lines = []
    for (key, value) in fields:
      lines.append('--' + BOUNDARY)
      lines.append('Content-Disposition: form-data; name="%s"' % key)
      lines.append('')  # blank line
      lines.append(value)
    for (key, filename, value) in files:
      lines.append('--' + BOUNDARY)
      lines.append(
          'Content-Disposition: form-data; name="%s"; filename="%s"'
          % (key, filename))
      lines.append('Content-Type: %s' % file_type)
      lines.append('')  # blank line
      lines.append(value)
    lines.append('--' + BOUNDARY + '--')
    lines.append('')  # blank line
    return CRLF.join(lines)

def GetUrl(url, tokens, data=None, cookies=False, anonymous=False):
  """Get URL, with GET or POST depending data, adds Authorization header.

  Args:
    url: Url to access.
    tokens: dictionary of authentication tokens for specific user.
    data: If a POST request, data to be sent with the request.
    cookies: boolean, True = send authentication tokens in cookie headers.
    anonymous: boolean, True = do not send login credentials.
  Returns:
    String: response to the HTTP request.
  """
  request = urllib2.Request(url)
  if not anonymous:
    if cookies:
      logger.debug('Adding authentication credentials to cookie header')
      request.add_header('Cookie', 'SID=%s; HSID=%s; SSID=%s' % (
          tokens['SID'], tokens['HSID'], tokens['SSID']))
    else:  # Don't add Auth headers when using Cookie header with auth tokens.   
      request.add_header('Authorization', 'GoogleLogin auth=%s' % tokens['Auth'])
  request.add_header('X-CloudPrint-Proxy', 'api-prober')
  if data:
    request.add_data(data)
    request.add_header('Content-Length', str(len(data)))
    request.add_header('Content-Type', 'multipart/form-data;boundary=%s' % BOUNDARY)

  # In case the gateway is not responding, we'll retry.
  retry_count = 0
  while retry_count < 5:
    try:
      result = urllib2.urlopen(request).read()
      return result
    except urllib2.HTTPError, e:
      # We see this error if the site goes down. We need to pause and retry.
      err_msg = 'Error accessing %s\n%s' % (url, e)
      logger.error(err_msg)
      logger.info('Pausing %d seconds', 60)
      time.sleep(60)
      retry_count += 1
      if retry_count == 5:
        return err_msg

def GetCookie(cookie_key, cookie_string):
    """Extract the cookie value from a set-cookie string.

    Args:
      cookie_key: string, cookie identifier.
      cookie_string: string, from a set-cookie command.
    Returns:
      string, value of cookie.
    """
    logger.debug('Getting cookie from %s', cookie_string)
    id_string = cookie_key + '='
    cookie_crumbs = cookie_string.split(';')
    for c in cookie_crumbs:
      if id_string in c:
        cookie = c.split(id_string)
        return cookie[1]
    return None

def ConvertJson(json_str):    
  """Convert json string to a python object.

  Args:
    json_str: string, json response.
  Returns:
    dictionary of deserialized json string.
  """
  j = {}
  try:
    j = json.loads(json_str)
    j['json'] = True
  except ValueError, e:
    # This means the format from json_str is probably bad.
    logger.error('Error parsing json string %s\n%s', json_str, e)
    j['json'] = False
    j['error'] = e

  return j

def GetKeyValue(line, sep=':'):
    """Return value from a key value pair string.

    Args:
      line: string containing key value pair.
      sep: separator of key and value.
    Returns:
      string: value from key value string.
    """
    s = line.split(sep)
    return StripPunc(s[1])

def StripPunc(s):
  """Strip puncuation from string, except for - sign.

  Args:
    s: string.
  Returns:
    string with puncuation removed.
  """
  for c in string.punctuation:
    if c == '-':  # Could be negative number, so don't remove '-'.
      continue
    else:
      s = s.replace(c, '')
  return s.strip()

def Validate(response):
  """Determine if JSON response indicated success."""
  if response.find('"success": true') > 0:
    return True
  else:
    return False

def GetMessage(response):
  """Extract the API message from a Cloud Print API json response.

  Args:
    response: json response from API request.
  Returns:
    string: message content in json response.
  """
  lines = response.split('\n')
  for line in lines:
    if '"message":' in line:
      msg = line.split(':')
      return msg[1]

  return None

def ReadFile(pathname):
  """Read contents of a file and return content.

  Args:
    pathname: string, (path)name of file.
  Returns:
    string: contents of file.
  """
  try:
    f = open(pathname, 'rb')
    try:
      s = f.read()
    except IOError, e:
      logger('Error reading %s\n%s', pathname, e)
    finally:
      f.close()
      return s
  except IOError, e:
    logger.error('Error opening %s\n%s', pathname, e)
    return None

def WriteFile(file_name, data):
  """Write contents of data to a file_name.

  Args:
    file_name: string, (path)name of file.
    data: string, contents to write to file.
  Returns:
    boolean: True = success, False = errors.
  """
  status = True

  try:
    f = open(file_name, 'wb')
    try:
      f.write(data)
    except IOError, e:
      logger.error('Error writing %s\n%s', file_name, e)
      status = False
    finally:
      f.close()
  except IOError, e:
    logger.error('Error opening %s\n%s', file_name, e)
    status = False

  return status

def Base64Encode(pathname):
  """Convert a file to a base64 encoded file.

  Args:
    pathname: path name of file to base64 encode..
  Returns:
    string, name of base64 encoded file.
  For more info on data urls, see:
    http://en.wikipedia.org/wiki/Data_URI_scheme
  """
  b64_pathname = pathname + '.b64'
  file_type = mimetypes.guess_type(pathname)[0] or 'application/octet-stream'
  data = ReadFile(pathname)

  # Convert binary data to base64 encoded data.
  header = 'data:%s;base64,' % file_type
  b64data = header + base64.b64encode(data)

  if WriteFile(b64_pathname, b64data):
    return b64_pathname
  else:
    return None



def GaiaLogin(email, password):
    """Login to gaia using HTTP post to the gaia login page.

    Args:
      email: string,
      password: string
    Returns:
      dictionary of authentication tokens.
    """
    tokens = {}
    cookie_keys = ['SID', 'LSID', 'HSID', 'SSID']
    email = email.replace('+', '%2B')
    # Needs to be some random string.
    galx_cookie = base64.b64encode('%s%s' % (email, time.time()))

    # Simulate submitting a gaia login form.
    form = ('ltmpl=login&fpui=1&rm=hide&hl=en-US&alwf=true'
            '&continue=https%%3A%%2F%%2F%s%%2F%s'
            '&followup=https%%3A%%2F%%2F%s%%2F%s'
            '&service=%s&Email=%s&Passwd=%s&GALX=%s' % (FOLLOWUP_HOST,
            FOLLOWUP_URI, FOLLOWUP_HOST, FOLLOWUP_URI, SERVICE, email,
            password, galx_cookie))
    login = httplib.HTTPS(GAIA_HOST, 443)
    login.putrequest('POST', LOGIN_URI)
    login.putheader('Host', GAIA_HOST)
    login.putheader('content-type', 'application/x-www-form-urlencoded')
    login.putheader('content-length', str(len(form)))
    login.putheader('Cookie', 'GALX=%s' % galx_cookie)
    logger.info('Sent POST content: %s', form)
    login.endheaders()
    logger.info('HTTP POST to https://%s%s', GAIA_HOST, LOGIN_URI)
    login.send(form)

    (errcode, errmsg, headers) = login.getreply()
    login_output = login.getfile()
    logger.info(headers)
    login_output.close()
    login.close()
    logger.info('Login complete.')

    if errcode != 302:
      logger.error('Gaia HTTP post returned %d, expected 302', errcode)
      logger.error('Message: %s', errmsg)

    for line in str(headers).split('\r\n'):
      if not line: continue
      (name, content) = line.split(':', 1)
      if name.lower() == 'set-cookie':
        for k in cookie_keys:
          if content.strip().startswith(k):
            tokens[k] = GetCookie(k, content)

    if not tokens:
      logger.error('No cookies received, check post parameters.')
      return None
    else:
      logger.debug('Received the following authorization tokens.')
      for t in tokens:
        logger.debug(t)
      return tokens

def GetAuthTokens(email, password):
    """Assign login credentials from GAIA accounts service.

    Args:
      email: Email address of the Google account to use.
      password: Cleartext password of the email account.
    Returns:
      dictionary containing Auth token.
    """
    # First get GAIA login credentials using our GaiaLogin method.
    logger.debug("GetAuthTokens")
    tokens = GaiaLogin(email, password)
    print tokens
    if tokens:

      # We still need to get the Auth token.    
      params = {'accountType': 'GOOGLE',
                'Email': email,
                'Passwd': password,
                'service': SERVICE,
                'source': CLIENT_NAME}
      stream = urllib.urlopen(LOGIN_URL, urllib.urlencode(params))

      for line in stream:
        if line.strip().startswith('Auth='):
          tokens['Auth'] = line.strip().replace('Auth=', '')

# All of the calls to GetUrl assume you've run something like this:
tokens = GetAuthTokens('email', 'password')

All of this code is straight from the google-cloud-print developer site.

Here is the last bit of the output.

INFO:__main__:Login complete.
ERROR:__main__:Gaia HTTP post returned 404, expected 302
ERROR:__main__:Message: Not Found
ERROR:__main__:No cookies received, check post parameters.
None

Thanks in advance!

Answer 1

replace this code

GAIA_HOST = 'www.google.com'
LOGIN_URI = '/accounts/ServiceLoginAuth'

by this

GAIA_HOST = 'accounts.google.com'
LOGIN_URI = '/ServiceLoginAuth'

Answer 2

I had the same problem. If you wish you can use a simple library and command line program I just published.

https://github.com/escube/GoogleCloudSpooler