Add auth via JWT providers (#2768)

* authentication via JWT providers
* add support for IAP JWT auth
* remove jwt_auth Blueprint and /headers endpoint
* fix pep8: imports

Author: SakuradaJun

redash/authentication/__init__.py

@@ -6,8 +6,11 @@
 import logging
 
 from flask import redirect, request, jsonify, url_for
+from werkzeug.exceptions import Unauthorized
 
 from redash import models, settings
+from redash.settings.organization import settings as org_settings
+from redash.authentication import jwt_auth
 from redash.authentication.org_resolving import current_org
 from redash.tasks import record_event
 
@@ -48,6 +51,21 @@ def load_user(user_id):
         return None
 
 
+def request_loader(request):
+    user = None
+    if settings.AUTH_TYPE == 'hmac':
+        user = hmac_load_user_from_request(request)
+    elif settings.AUTH_TYPE == 'api_key':
+        user = api_key_load_user_from_request(request)
+    else:
+        logger.warning("Unknown authentication type ({}). Using default (HMAC).".format(settings.AUTH_TYPE))
+        user = hmac_load_user_from_request(request)
+
+    if org_settings['auth_jwt_login_enabled'] and user is None:
+        user = jwt_token_load_user_from_request(request)
+    return user
+
+
 def hmac_load_user_from_request(request):
     signature = request.args.get('signature')
     expires = float(request.args.get('expires') or 0)
@@ -116,6 +134,40 @@ def api_key_load_user_from_request(request):
     return user
 
 
+def jwt_token_load_user_from_request(request):
+    org = current_org._get_current_object()
+
+    payload = None
+
+    if org_settings['auth_jwt_auth_cookie_name']:
+        jwt_token = request.cookies.get(org_settings['auth_jwt_auth_cookie_name'], None)
+    elif org_settings['auth_jwt_auth_header_name']:
+        jwt_token = request.headers.get(org_settings['auth_jwt_auth_header_name'], None)
+    else:
+        return None
+
+    if jwt_token:
+        payload, token_is_valid = jwt_auth.verify_jwt_token(
+            jwt_token,
+            expected_issuer=org_settings['auth_jwt_auth_issuer'],
+            expected_audience=org_settings['auth_jwt_auth_audience'],
+            algorithms=org_settings['auth_jwt_auth_algorithms'],
+            public_certs_url=org_settings['auth_jwt_auth_public_certs_url'],
+        )
+        if not token_is_valid:
+            raise Unauthorized('Invalid JWT token')
+
+    if not payload:
+        return
+
+    try:
+        user = models.User.get_by_email_and_org(payload['email'], org)
+    except models.NoResultFound:
+        user = create_and_login_user(current_org, payload['email'], payload['email'])
+
+    return user
+
+
 def log_user_logged_in(app, user):
     event = {
         'org_id': current_org.id,
@@ -168,14 +220,7 @@ def setup_authentication(app):
     app.register_blueprint(ldap_auth.blueprint)
 
     user_logged_in.connect(log_user_logged_in)
-
-    if settings.AUTH_TYPE == 'hmac':
-        login_manager.request_loader(hmac_load_user_from_request)
-    elif settings.AUTH_TYPE == 'api_key':
-        login_manager.request_loader(api_key_load_user_from_request)
-    else:
-        logger.warning("Unknown authentication type ({}). Using default (HMAC).".format(settings.AUTH_TYPE))
-        login_manager.request_loader(hmac_load_user_from_request)
+    login_manager.request_loader(request_loader)
 
 
 def create_and_login_user(org, name, email, picture=None):

redash/authentication/jwt_auth.py

@@ -0,0 +1,65 @@
+import logging
+import json
+import jwt
+import requests
+
+logger = logging.getLogger('jwt_auth')
+
+
+def get_public_keys(url):
+    """
+    Returns:
+        List of RSA public keys usable by PyJWT.
+    """
+    key_cache = get_public_keys.key_cache
+    if url in key_cache:
+        return key_cache[url]
+    else:
+        r = requests.get(url)
+        r.raise_for_status()
+        data = r.json()
+        if 'keys' in data:
+            public_keys = []
+            for key_dict in data['keys']:
+                public_key = jwt.algorithms.RSAAlgorithm.from_jwk(json.dumps(key_dict))
+                public_keys.append(public_key)
+
+            get_public_keys.key_cache[url] = public_keys
+            return public_keys
+        else:
+            get_public_keys.key_cache[url] = data
+            return data
+
+
+get_public_keys.key_cache = {}
+
+
+def verify_jwt_token(jwt_token, expected_issuer, expected_audience, algorithms, public_certs_url):
+    # https://developers.cloudflare.com/access/setting-up-access/validate-jwt-tokens/
+    # https://cloud.google.com/iap/docs/signed-headers-howto
+    # Loop through the keys since we can't pass the key set to the decoder
+    keys = get_public_keys(public_certs_url)
+
+    key_id = jwt.get_unverified_header(jwt_token).get('kid', '')
+    if key_id and isinstance(keys, dict):
+        keys = [keys.get(key_id)]
+
+    valid_token = False
+    payload = None
+    for key in keys:
+        try:
+            # decode returns the claims which has the email if you need it
+            payload = jwt.decode(
+                jwt_token,
+                key=key,
+                audience=expected_audience,
+                algorithms=algorithms
+            )
+            issuer = payload['iss']
+            if issuer != expected_issuer:
+                raise Exception('Wrong issuer: {}'.format(issuer))
+            valid_token = True
+            break
+        except Exception as e:
+            logging.exception(e)
+    return payload, valid_token

redash/settings/organization.py

@@ -17,11 +17,26 @@
 
 DATE_FORMAT = os.environ.get("REDASH_DATE_FORMAT", "DD/MM/YY")
 
+JWT_LOGIN_ENABLED = parse_boolean(os.environ.get("REDASH_JWT_LOGIN_ENABLED", "false"))
+JWT_AUTH_ISSUER = os.environ.get("REDASH_JWT_AUTH_ISSUER", "")
+JWT_AUTH_PUBLIC_CERTS_URL = os.environ.get("REDASH_JWT_AUTH_PUBLIC_CERTS_URL", "")
+JWT_AUTH_AUDIENCE = os.environ.get("REDASH_JWT_AUTH_AUDIENCE", "")
+JWT_AUTH_ALGORITHMS = os.environ.get("REDASH_JWT_AUTH_ALGORITHMS", "HS256,RS256,ES256").split(',')
+JWT_AUTH_COOKIE_NAME = os.environ.get("REDASH_JWT_AUTH_COOKIE_NAME", "")
+JWT_AUTH_HEADER_NAME = os.environ.get("REDASH_JWT_AUTH_HEADER_NAME", "")
+
 settings = {
     "auth_password_login_enabled": PASSWORD_LOGIN_ENABLED,
     "auth_saml_enabled": SAML_LOGIN_ENABLED,
     "auth_saml_entity_id": SAML_ENTITY_ID,
     "auth_saml_metadata_url": SAML_METADATA_URL,
     "auth_saml_nameid_format": SAML_NAMEID_FORMAT,
-    "date_format": DATE_FORMAT
+    "date_format": DATE_FORMAT,
+    "auth_jwt_login_enabled": JWT_LOGIN_ENABLED,
+    "auth_jwt_auth_issuer": JWT_AUTH_ISSUER,
+    "auth_jwt_auth_public_certs_url": JWT_AUTH_PUBLIC_CERTS_URL,
+    "auth_jwt_auth_audience": JWT_AUTH_AUDIENCE,
+    "auth_jwt_auth_algorithms": JWT_AUTH_ALGORITHMS,
+    "auth_jwt_auth_cookie_name": JWT_AUTH_COOKIE_NAME,
+    "auth_jwt_auth_header_name": JWT_AUTH_HEADER_NAME,
 }

requirements.txt

@@ -44,6 +44,7 @@ semver==2.2.1
 xlsxwriter==0.9.3
 pystache==0.5.4
 parsedatetime==2.1
+PyJWT==1.6.4
 cryptography==2.0.2
 simplejson==3.10.0
 ua-parser==0.7.3