Remove the review bot app.

reviewbot/third_party/google-api-python-client/oauth2client/crypt.py

-#!/usr/bin/python2.4
-# -*- coding: utf-8 -*-
-#
-# Copyright (C) 2011 Google Inc.
-#
-# 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.
-
-import base64
-import hashlib
-import logging
-import time
-
-from anyjson import simplejson
-
-
-CLOCK_SKEW_SECS = 300  # 5 minutes in seconds
-AUTH_TOKEN_LIFETIME_SECS = 300  # 5 minutes in seconds
-MAX_TOKEN_LIFETIME_SECS = 86400  # 1 day in seconds
-
-
-logger = logging.getLogger(__name__)
-
-
-class AppIdentityError(Exception):
-  pass
-
-
-try:
-  from OpenSSL import crypto
-
-
-  class OpenSSLVerifier(object):
-    """Verifies the signature on a message."""
-
-    def __init__(self, pubkey):
-      """Constructor.
-
-      Args:
-        pubkey, OpenSSL.crypto.PKey, The public key to verify with.
-      """
-      self._pubkey = pubkey
-
-    def verify(self, message, signature):
-      """Verifies a message against a signature.
-
-      Args:
-        message: string, The message to verify.
-        signature: string, The signature on the message.
-
-      Returns:
-        True if message was signed by the private key associated with the public
-        key that this object was constructed with.
-      """
-      try:
-        crypto.verify(self._pubkey, signature, message, 'sha256')
-        return True
-      except:
-        return False
-
-    @staticmethod
-    def from_string(key_pem, is_x509_cert):
-      """Construct a Verified instance from a string.
-
-      Args:
-        key_pem: string, public key in PEM format.
-        is_x509_cert: bool, True if key_pem is an X509 cert, otherwise it is
-          expected to be an RSA key in PEM format.
-
-      Returns:
-        Verifier instance.
-
-      Raises:
-        OpenSSL.crypto.Error if the key_pem can't be parsed.
-      """
-      if is_x509_cert:
-        pubkey = crypto.load_certificate(crypto.FILETYPE_PEM, key_pem)
-      else:
-        pubkey = crypto.load_privatekey(crypto.FILETYPE_PEM, key_pem)
-      return OpenSSLVerifier(pubkey)
-
-
-  class OpenSSLSigner(object):
-    """Signs messages with a private key."""
-
-    def __init__(self, pkey):
-      """Constructor.
-
-      Args:
-        pkey, OpenSSL.crypto.PKey (or equiv), The private key to sign with.
-      """
-      self._key = pkey
-
-    def sign(self, message):
-      """Signs a message.
-
-      Args:
-        message: string, Message to be signed.
-
-      Returns:
-        string, The signature of the message for the given key.
-      """
-      return crypto.sign(self._key, message, 'sha256')
-
-    @staticmethod
-    def from_string(key, password='notasecret'):
-      """Construct a Signer instance from a string.
-
-      Args:
-        key: string, private key in PKCS12 or PEM format.
-        password: string, password for the private key file.
-
-      Returns:
-        Signer instance.
-
-      Raises:
-        OpenSSL.crypto.Error if the key can't be parsed.
-      """
-      if key.startswith('-----BEGIN '):
-        pkey = crypto.load_privatekey(crypto.FILETYPE_PEM, key)
-      else:
-        pkey = crypto.load_pkcs12(key, password).get_privatekey()
-      return OpenSSLSigner(pkey)
-
-except ImportError:
-  OpenSSLVerifier = None
-  OpenSSLSigner = None
-
-
-try:
-  from Crypto.PublicKey import RSA
-  from Crypto.Hash import SHA256
-  from Crypto.Signature import PKCS1_v1_5
-
-
-  class PyCryptoVerifier(object):
-    """Verifies the signature on a message."""
-
-    def __init__(self, pubkey):
-      """Constructor.
-
-      Args:
-        pubkey, OpenSSL.crypto.PKey (or equiv), The public key to verify with.
-      """
-      self._pubkey = pubkey
-
-    def verify(self, message, signature):
-      """Verifies a message against a signature.
-
-      Args:
-        message: string, The message to verify.
-        signature: string, The signature on the message.
-
-      Returns:
-        True if message was signed by the private key associated with the public
-        key that this object was constructed with.
-      """
-      try:
-        return PKCS1_v1_5.new(self._pubkey).verify(
-            SHA256.new(message), signature)
-      except:
-        return False
-
-    @staticmethod
-    def from_string(key_pem, is_x509_cert):
-      """Construct a Verified instance from a string.
-
-      Args:
-        key_pem: string, public key in PEM format.
-        is_x509_cert: bool, True if key_pem is an X509 cert, otherwise it is
-          expected to be an RSA key in PEM format.
-
-      Returns:
-        Verifier instance.
-
-      Raises:
-        NotImplementedError if is_x509_cert is true.
-      """
-      if is_x509_cert:
-        raise NotImplementedError(
-            'X509 certs are not supported by the PyCrypto library. '
-            'Try using PyOpenSSL if native code is an option.')
-      else:
-        pubkey = RSA.importKey(key_pem)
-      return PyCryptoVerifier(pubkey)
-
-
-  class PyCryptoSigner(object):
-    """Signs messages with a private key."""
-
-    def __init__(self, pkey):
-      """Constructor.
-
-      Args:
-        pkey, OpenSSL.crypto.PKey (or equiv), The private key to sign with.
-      """
-      self._key = pkey
-
-    def sign(self, message):
-      """Signs a message.
-
-      Args:
-        message: string, Message to be signed.
-
-      Returns:
-        string, The signature of the message for the given key.
-      """
-      return PKCS1_v1_5.new(self._key).sign(SHA256.new(message))
-
-    @staticmethod
-    def from_string(key, password='notasecret'):
-      """Construct a Signer instance from a string.
-
-      Args:
-        key: string, private key in PEM format.
-        password: string, password for private key file. Unused for PEM files.
-
-      Returns:
-        Signer instance.
-
-      Raises:
-        NotImplementedError if they key isn't in PEM format.
-      """
-      if key.startswith('-----BEGIN '):
-        pkey = RSA.importKey(key)
-      else:
-        raise NotImplementedError(
-            'PKCS12 format is not supported by the PyCrpto library. '
-            'Try converting to a "PEM" '
-            '(openssl pkcs12 -in xxxxx.p12 -nodes -nocerts > privatekey.pem) '
-            'or using PyOpenSSL if native code is an option.')
-      return PyCryptoSigner(pkey)
-
-except ImportError:
-  PyCryptoVerifier = None
-  PyCryptoSigner = None
-
-
-if OpenSSLSigner:
-  Signer = OpenSSLSigner
-  Verifier = OpenSSLVerifier
-elif PyCryptoSigner:
-  Signer = PyCryptoSigner
-  Verifier = PyCryptoVerifier
-else:
-  raise ImportError('No encryption library found. Please install either '
-                    'PyOpenSSL, or PyCrypto 2.6 or later')
-
-
-def _urlsafe_b64encode(raw_bytes):
-  return base64.urlsafe_b64encode(raw_bytes).rstrip('=')
-
-
-def _urlsafe_b64decode(b64string):
-  # Guard against unicode strings, which base64 can't handle.
-  b64string = b64string.encode('ascii')
-  padded = b64string + '=' * (4 - len(b64string) % 4)
-  return base64.urlsafe_b64decode(padded)
-
-
-def _json_encode(data):
-  return simplejson.dumps(data, separators = (',', ':'))
-
-
-def make_signed_jwt(signer, payload):
-  """Make a signed JWT.
-
-  See http://self-issued.info/docs/draft-jones-json-web-token.html.
-
-  Args:
-    signer: crypt.Signer, Cryptographic signer.
-    payload: dict, Dictionary of data to convert to JSON and then sign.
-
-  Returns:
-    string, The JWT for the payload.
-  """
-  header = {'typ': 'JWT', 'alg': 'RS256'}
-
-  segments = [
-          _urlsafe_b64encode(_json_encode(header)),
-          _urlsafe_b64encode(_json_encode(payload)),
-  ]
-  signing_input = '.'.join(segments)
-
-  signature = signer.sign(signing_input)
-  segments.append(_urlsafe_b64encode(signature))
-
-  logger.debug(str(segments))
-
-  return '.'.join(segments)
-
-
-def verify_signed_jwt_with_certs(jwt, certs, audience):
-  """Verify a JWT against public certs.
-
-  See http://self-issued.info/docs/draft-jones-json-web-token.html.
-
-  Args:
-    jwt: string, A JWT.
-    certs: dict, Dictionary where values of public keys in PEM format.
-    audience: string, The audience, 'aud', that this JWT should contain. If
-      None then the JWT's 'aud' parameter is not verified.
-
-  Returns:
-    dict, The deserialized JSON payload in the JWT.
-
-  Raises:
-    AppIdentityError if any checks are failed.
-  """
-  segments = jwt.split('.')
-
-  if (len(segments) != 3):
-    raise AppIdentityError(
-      'Wrong number of segments in token: %s' % jwt)
-  signed = '%s.%s' % (segments[0], segments[1])
-
-  signature = _urlsafe_b64decode(segments[2])
-
-  # Parse token.
-  json_body = _urlsafe_b64decode(segments[1])
-  try:
-    parsed = simplejson.loads(json_body)
-  except:
-    raise AppIdentityError('Can\'t parse token: %s' % json_body)
-
-  # Check signature.
-  verified = False
-  for (keyname, pem) in certs.items():
-    verifier = Verifier.from_string(pem, True)
-    if (verifier.verify(signed, signature)):
-      verified = True
-      break
-  if not verified:
-    raise AppIdentityError('Invalid token signature: %s' % jwt)
-
-  # Check creation timestamp.
-  iat = parsed.get('iat')
-  if iat is None:
-    raise AppIdentityError('No iat field in token: %s' % json_body)
-  earliest = iat - CLOCK_SKEW_SECS
-
-  # Check expiration timestamp.
-  now = long(time.time())
-  exp = parsed.get('exp')
-  if exp is None:
-    raise AppIdentityError('No exp field in token: %s' % json_body)
-  if exp >= now + MAX_TOKEN_LIFETIME_SECS:
-    raise AppIdentityError(
-      'exp field too far in future: %s' % json_body)
-  latest = exp + CLOCK_SKEW_SECS
-
-  if now < earliest:
-    raise AppIdentityError('Token used too early, %d < %d: %s' %
-      (now, earliest, json_body))
-  if now > latest:
-    raise AppIdentityError('Token used too late, %d > %d: %s' %
-      (now, latest, json_body))
-
-  # Check audience.
-  if audience is not None:
-    aud = parsed.get('aud')
-    if aud is None:
-      raise AppIdentityError('No aud field in token: %s' % json_body)
-    if aud != audience:
-      raise AppIdentityError('Wrong recipient, %s != %s: %s' %
-          (aud, audience, json_body))
-
-  return parsed