Update oauth2client to v2.0.1 and googleapiclient to v1.5.0.

appengine/third_party/oauth2client/xsrfutil.py

-#
-# Copyright 2014 the Melange authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#   http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-"""Helper methods for creating & verifying XSRF tokens."""
-
-__authors__ = [
-    '"Doug Coker" <dcoker@google.com>',
-    '"Joe Gregorio" <jcgregorio@google.com>',
-]
-
-
-import base64
-import hmac
-import time
-
-import six
-from oauth2client import util
-
-
-# Delimiter character
-DELIMITER = b':'
-
-
-# 1 hour in seconds
-DEFAULT_TIMEOUT_SECS = 1*60*60
-
-
-def _force_bytes(s):
-    if isinstance(s, bytes):
-        return s
-    s = str(s)
-    if isinstance(s, six.text_type):
-        return s.encode('utf-8')
-    return s
-
-
-@util.positional(2)
-def generate_token(key, user_id, action_id="", when=None):
-  """Generates a URL-safe token for the given user, action, time tuple.
-
-  Args:
-    key: secret key to use.
-    user_id: the user ID of the authenticated user.
-    action_id: a string identifier of the action they requested
-      authorization for.
-    when: the time in seconds since the epoch at which the user was
-      authorized for this action. If not set the current time is used.
-
-  Returns:
-    A string XSRF protection token.
-  """
-  when = _force_bytes(when or int(time.time()))
-  digester = hmac.new(_force_bytes(key))
-  digester.update(_force_bytes(user_id))
-  digester.update(DELIMITER)
-  digester.update(_force_bytes(action_id))
-  digester.update(DELIMITER)
-  digester.update(when)
-  digest = digester.digest()
-
-  token = base64.urlsafe_b64encode(digest + DELIMITER + when)
-  return token
-
-
-@util.positional(3)
-def validate_token(key, token, user_id, action_id="", current_time=None):
-  """Validates that the given token authorizes the user for the action.
-
-  Tokens are invalid if the time of issue is too old or if the token
-  does not match what generateToken outputs (i.e. the token was forged).
-
-  Args:
-    key: secret key to use.
-    token: a string of the token generated by generateToken.
-    user_id: the user ID of the authenticated user.
-    action_id: a string identifier of the action they requested
-      authorization for.
-
-  Returns:
-    A boolean - True if the user is authorized for the action, False
-    otherwise.
-  """
-  if not token:
-    return False
-  try:
-    decoded = base64.urlsafe_b64decode(token)
-    token_time = int(decoded.split(DELIMITER)[-1])
-  except (TypeError, ValueError):
-    return False
-  if current_time is None:
-    current_time = time.time()
-  # If the token is too old it's not valid.
-  if current_time - token_time > DEFAULT_TIMEOUT_SECS:
-    return False
-
-  # The given token should match the generated one with the same time.
-  expected_token = generate_token(key, user_id, action_id=action_id,
-                                  when=token_time)
-  if len(token) != len(expected_token):
-    return False
-
-  # Perform constant time comparison to avoid timing attacks
-  different = 0
-  for x, y in zip(bytearray(token), bytearray(expected_token)):
-    different |= x ^ y
-  return not different