From 82583865497ef3c2bc802fc951e36bcb32d96f82 Mon Sep 17 00:00:00 2001
From: tristangoogle <tvanech@google.com>
Date: Thu, 1 Sep 2016 11:44:27 -0700
Subject: [PATCH] Delete firebase_helper.py

---
 .../standard/firebase/auth/firebase_helper.py | 105 ------------------
 1 file changed, 105 deletions(-)
 delete mode 100644 appengine/standard/firebase/auth/firebase_helper.py

diff --git a/appengine/standard/firebase/auth/firebase_helper.py b/appengine/standard/firebase/auth/firebase_helper.py
deleted file mode 100644
index 21b06f9c1e7a..000000000000
--- a/appengine/standard/firebase/auth/firebase_helper.py
+++ /dev/null
@@ -1,105 +0,0 @@
-# Copyright 2016 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 json
-import logging
-import os
-import ssl
-
-from Crypto.Util import asn1
-from flask import request
-from google.appengine.api import urlfetch, urlfetch_errors
-import jwt
-from jwt.contrib.algorithms.pycrypto import RSAAlgorithm
-import jwt.exceptions
-
-
-# For App Engine, pyjwt needs to use PyCrypto instead of Cryptography.
-jwt.register_algorithm('RS256', RSAAlgorithm(RSAAlgorithm.SHA256))
-
-FIREBASE_PUBLIC_KEYS_URL = (
-    'https://www.googleapis.com/robot/v1/metadata/x509/'
-    'securetoken@system.gserviceaccount.com')
-
-
-def get_firebase_certificates():
-    """Fetches the firebase certificates from firebase.
-
-    Note: in a production application, you should cache this for at least
-    an hour.
-    """
-    try:
-        result = urlfetch.Fetch(FIREBASE_CERTIFICATES_URL,
-                                validate_certificate=True)
-        data = result.content
-    except urlfetch_errors.Error:
-        logging.error('Error while fetching Firebase certificates')
-        raise
-
-    certificates = json.loads(data)
-
-    return certificates
-
-
-def extract_public_key_from_certificate(x509_certificate):
-    """Extracts the PEM public key from an x509 certificate."""
-    der_certificate_string = ssl.PEM_cert_to_DER_cert(x509_certificate)
-
-    # Extract subjectPublicKeyInfo field from X.509 certificate (see RFC3280)
-    der_certificate = asn1.DerSequence()
-    der_certificate.decode(der_certificate_string)
-    tbs_certification = asn1.DerSequence()  # To Be Signed certificate
-    tbs_certification.decode(der_certificate[0])
-
-    subject_public_key_info = tbs_certification[6]
-
-    return subject_public_key_info
-
-
-def verify_auth_token():
-    """Verifies the JWT auth token in the request.
-    If none is found or if the token is invalid, returns None. Otherwise,
-    it returns a dictionary containing the JWT claims."""
-    if 'Authorization' not in request.headers:
-        return None
-
-    # Auth header is in format 'Bearer {jwt}'.
-    request_jwt = request.headers['Authorization'].split(' ').pop()
-
-    # Determine which certificate was used to sign the JWT.
-    header = jwt.get_unverified_header(request_jwt)
-    kid = header['kid']
-
-    certificates = get_firebase_certificates()
-
-    try:
-        certificate = certificates[kid]
-    except KeyError:
-        logging.warning('JWT signed with unkown kid {}'.format(header['kid']))
-        return None
-
-    # Get the public key from the certificate. This is used to verify the
-    # jwt signature.
-    public_key = extract_public_key_from_certificate(certificate)
-
-    try:
-        claims = jwt.decode(
-            request_jwt,
-            public_key,
-            algorithms=['RS256'],
-            audience=os.environ['FIREBASE_PROJECT_ID'])
-    except jwt.exceptions.InvalidTokenError as e:
-        logging.warning('JWT verification failed: {}'.format(e))
-        return None
-
-    return claims