Fix #847 Log an exception when response status is not OK (#848)

* Fix #847 Log an exception if the response from authentication server is not successful

By providing the status code and its reason to logger, the error message would be more explicit for debugger whenever there is an issue related to resource token or other errors.

* Test to check logger information when auth response is not correct

* Lint code to change bad quotes and add author information

* Change import position

* Add CHANGLOG for fix #847

Author: Chouvic

AUTHORS

@@ -29,3 +29,4 @@ pySilver
 Rodney Richardson
 Silvano Cerza
 Stéphane Raimbault
+Jun Zhou

CHANGELOG.md

@@ -19,6 +19,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### added
 * added `select_related` in intospect view for better query performance
 
+### Fixed
+* #847: Fix inappropriate message when response from authentication server is not OK.
 
 ## [1.3.2] 2020-03-24
 

oauth2_provider/oauth2_validators.py

@@ -1,5 +1,6 @@
 import base64
 import binascii
+import http.client
 import logging
 from collections import OrderedDict
 from datetime import datetime, timedelta
@@ -304,6 +305,14 @@ def _get_token_from_authentication_server(
             log.exception("Introspection: Failed POST to %r in token lookup", introspection_url)
             return None
 
+        # Log an exception when response from auth server is not successful
+        if response.status_code != http.client.OK:
+            log.exception("Introspection: Failed to get a valid response "
+                          "from authentication server. Status code: {}, "
+                          "Reason: {}.".format(response.status_code,
+                                               response.reason))
+            return None
+
         try:
             content = response.json()
         except ValueError:

tests/test_oauth2_validators.py

@@ -2,7 +2,7 @@
 import datetime
 
 from django.contrib.auth import get_user_model
-from django.test import TransactionTestCase
+from django.test import TestCase, TransactionTestCase
 from django.utils import timezone
 from oauthlib.common import Request
 
@@ -392,3 +392,26 @@ def test_validate_bearer_token_adds_error_to_the_request_when_a_invalid_custom_t
         self.assertDictEqual(self.request.oauth2_error, {
             "error": "invalid_token",
         })
+
+
+class TestOAuth2ValidatorErrorResourceToken(TestCase):
+    """The following tests check logger information when response from oauth2
+    is unsuccessful.
+    """
+
+    def setUp(self):
+        self.token = "test_token"
+        self.introspection_url = "http://example.com/token/introspection/"
+        self.introspection_token = "test_introspection_token"
+        self.validator = OAuth2Validator()
+
+    def test_response_when_auth_server_response_return_404(self):
+        with self.assertLogs(logger="oauth2_provider") as mock_log:
+            self.validator._get_token_from_authentication_server(
+                self.token, self.introspection_url,
+                self.introspection_token, None)
+            self.assertIn("ERROR:oauth2_provider:Introspection: Failed to "
+                          "get a valid response from authentication server. "
+                          "Status code: 404, Reason: "
+                          "Not Found.\nNoneType: None",
+                          mock_log.output)