api: Migrate to Auth0 for API authorization

This change updates the OpenDC API to use Auth0 for API authorization.
This removes the hard dependency on Google for logging into OpenDC and
simplifies implementation as we do not have to store user information
anymore, other than the user identifier.

1 files changed, 10 insertions, 37 deletions

diff --git a/opendc-web/opendc-web-api/app.py b/opendc-web/opendc-web-api/app.py
index 7a687678..ee4b3d32 100755
--- a/opendc-web/opendc-web-api/app.py
+++ b/opendc-web/opendc-web-api/app.py
@@ -3,16 +3,14 @@ import json
 import os
 import sys
 import traceback
-import urllib.request
 
 from dotenv import load_dotenv
 from flask import Flask, request, jsonify
 from flask_compress import Compress
 from flask_cors import CORS
-from oauth2client import client, crypt
 
-from opendc.models.user import User
 from opendc.util import rest, path_parser, database
+from opendc.util.auth import AuthError, AuthManager, AsymmetricJwtAlgorithm
 from opendc.util.exceptions import AuthorizationTokenError, RequestInitializationError
 from opendc.util.json import JSONEncoder
 
@@ -50,46 +48,21 @@ CORS(app)
 compress = Compress()
 compress.init_app(app)
 
-API_VERSIONS = {'v2'}
-
-
-@app.route('/tokensignin', methods=['POST'])
-def sign_in():
-    """Authenticate a user with Google sign in"""
+auth = AuthManager(AsymmetricJwtAlgorithm(jwks_url=f"https://{os.environ['AUTH0_DOMAIN']}/.well-known/jwks.json"),
+                   issuer=f"https://{os.environ['AUTH0_DOMAIN']}/", audience=os.environ['AUTH0_AUDIENCE'])
 
-    try:
-        token = request.form['idtoken']
-    except KeyError:
-        return 'No idtoken provided', 401
-
-    try:
-        idinfo = client.verify_id_token(token, os.environ['OPENDC_OAUTH_CLIENT_ID'])
-
-        if idinfo['aud'] != os.environ['OPENDC_OAUTH_CLIENT_ID']:
-            raise crypt.AppIdentityError('Unrecognized client.')
-
-        if idinfo['iss'] not in ['accounts.google.com', 'https://accounts.google.com']:
-            raise crypt.AppIdentityError('Wrong issuer.')
-    except ValueError:
-        url = "https://www.googleapis.com/oauth2/v3/tokeninfo?id_token={}".format(token)
-        req = urllib.request.Request(url)
-        response = urllib.request.urlopen(url=req, timeout=30)
-        res = response.read()
-        idinfo = json.loads(res)
-    except crypt.AppIdentityError as e:
-        return 'Did not successfully authenticate'
-
-    user = User.from_google_id(idinfo['sub'])
-
-    data = {'isNewUser': user.obj is None}
+API_VERSIONS = {'v2'}
 
-    if user.obj is not None:
-        data['userId'] = user.get_id()
 
-    return jsonify(**data)
+@app.errorhandler(AuthError)
+def handle_auth_error(ex):
+    response = jsonify(ex.error)
+    response.status_code = ex.status_code
+    return response
 
 
 @app.route('/<string:version>/<path:endpoint_path>', methods=['GET', 'POST', 'PUT', 'DELETE'])
+@auth.require
 def api_call(version, endpoint_path):
     """Call an API endpoint directly over HTTP."""