Expire auth code after 10 minutes

homeassistant/components/auth/__init__.py

@@ -102,6 +102,7 @@
     "token_type": "Bearer"
 }
 """
+from datetime import timedelta
 import logging
 import uuid
 
@@ -114,6 +115,7 @@
     FlowManagerIndexView, FlowManagerResourceView)
 from homeassistant.components.http.view import HomeAssistantView
 from homeassistant.components.http.data_validator import RequestDataValidator
+from homeassistant.util import dt as dt_util
 
 from . import indieauth
 
@@ -349,12 +351,26 @@ def _create_cred_store():
     def store_credentials(client_id, credentials):
         """Store credentials and return a code to retrieve it."""
         code = uuid.uuid4().hex
-        temp_credentials[(client_id, code)] = credentials
+        temp_credentials[(client_id, code)] = (dt_util.utcnow(), credentials)
         return code
 
     @callback
     def retrieve_credentials(client_id, code):
         """Retrieve credentials."""
-        return temp_credentials.pop((client_id, code), None)
+        key = (client_id, code)
+
+        if key not in temp_credentials:
+            return None
+
+        created, credentials = temp_credentials.pop(key)
+
+        # OAuth 4.2.1
+        # The authorization code MUST expire shortly after it is issued to
+        # mitigate the risk of leaks.  A maximum authorization code lifetime of
+        # 10 minutes is RECOMMENDED.
+        if dt_util.utcnow() - created < timedelta(minutes=10):
+            return credentials
+
+        return None
 
     return store_credentials, retrieve_credentials

tests/components/auth/test_init.py

@@ -1,4 +1,10 @@
 """Integration tests for the auth component."""
+from datetime import timedelta
+from unittest.mock import patch
+
+from homeassistant.util.dt import utcnow
+from homeassistant.components import auth
+
 from . import async_setup_auth
 
 from tests.common import CLIENT_ID, CLIENT_REDIRECT_URI
@@ -58,3 +64,25 @@ async def test_login_new_user_and_refresh_token(hass, aiohttp_client):
         'authorization': 'Bearer {}'.format(tokens['access_token'])
     })
     assert resp.status == 200
+
+
+def test_credential_store_expiration():
+    """Test that the credential store will not return expired tokens."""
+    store, retrieve = auth._create_cred_store()
+    client_id = 'bla'
+    credentials = 'creds'
+    now = utcnow()
+
+    with patch('homeassistant.util.dt.utcnow', return_value=now):
+        code = store(client_id, credentials)
+
+    with patch('homeassistant.util.dt.utcnow',
+               return_value=now + timedelta(minutes=10)):
+        assert retrieve(client_id, code) is None
+
+    with patch('homeassistant.util.dt.utcnow', return_value=now):
+        code = store(client_id, credentials)
+
+    with patch('homeassistant.util.dt.utcnow',
+               return_value=now + timedelta(minutes=9, seconds=59)):
+        assert retrieve(client_id, code) == credentials