treat the ssiExamLocator as potentially case insensitive, since I've seen…

treat the ssiExamLocator as potentially case insensitive, since I've seen different casing used in different user-cases

edx_proctoring/backends/software_secure.py

@@ -152,7 +152,10 @@ class SoftwareSecureBackendProvider(ProctoringBackendProvider):
                 raise StudentExamAttemptDoesNotExistsException(err_msg)
 
         # then make sure we have the right external_id
-        if attempt_obj.external_id != external_id:
+        # note that SoftwareSecure might send a case insensitive
+        # ssiRecordLocator than what it returned when we registered the
+        # exam
+        if attempt_obj.external_id.lower() != external_id.lower():
             err_msg = (
                 'Found attempt_code {attempt_code}, but the recorded external_id did not '
                 'match the ssiRecordLocator that had been recorded previously. Has {existing} '

edx_proctoring/callbacks.py

@@ -18,6 +18,8 @@ from edx_proctoring.api import (
     mark_exam_attempt_as_ready,
     update_exam_attempt)
 
+from edx_proctoring.exceptions import ProctoredBaseException
+
 from edx_proctoring.backends import get_backend_provider
 
 log = logging.getLogger(__name__)
@@ -77,7 +79,15 @@ class ExamReviewCallback(APIView):
         provider = get_backend_provider()
 
         # call down into the underlying provider code
-        provider.on_review_callback(request.DATA)
+        try:
+            provider.on_review_callback(request.DATA)
+        except ProctoredBaseException, ex:
+            return Response(
+                data={
+                    'reason': unicode(ex)
+                },
+                status=400
+            )
 
         return Response(
             data='OK',

edx_proctoring/tests/test_views.py

@@ -1004,6 +1004,80 @@ class TestStudentProctoredExamAttempt(LoggedInTestCase):
         )
         self.assertEqual(response.status_code, 200)
 
+    def test_review_caseinsensitive(self):
+        """
+        Simulates a callback from the proctoring service with the
+        review data
+        """
+
+        exam_id = create_exam(
+            course_id='foo/bar/baz',
+            content_id='content',
+            exam_name='Sample Exam',
+            time_limit_mins=10,
+            is_proctored=True
+        )
+
+        # be sure to use the mocked out SoftwareSecure handlers
+        with HTTMock(mock_response_content):
+            attempt_id = create_exam_attempt(
+                exam_id,
+                self.user.id,
+                taking_as_proctored=True
+            )
+
+        attempt = get_exam_attempt_by_id(attempt_id)
+        self.assertIsNotNone(attempt['external_id'])
+
+        test_payload = Template(TEST_REVIEW_PAYLOAD).substitute(
+            attempt_code=attempt['attempt_code'],
+            external_id=attempt['external_id'].upper()
+        )
+
+        response = self.client.post(
+            reverse('edx_proctoring.anonymous.proctoring_review_callback'),
+            data=test_payload,
+            content_type='application/json'
+        )
+        self.assertEqual(response.status_code, 200)
+
+    def test_review_mismatch(self):
+        """
+        Simulates a callback from the proctoring service with the
+        review data but the external_ids don't match
+        """
+
+        exam_id = create_exam(
+            course_id='foo/bar/baz',
+            content_id='content',
+            exam_name='Sample Exam',
+            time_limit_mins=10,
+            is_proctored=True
+        )
+
+        # be sure to use the mocked out SoftwareSecure handlers
+        with HTTMock(mock_response_content):
+            attempt_id = create_exam_attempt(
+                exam_id,
+                self.user.id,
+                taking_as_proctored=True
+            )
+
+        attempt = get_exam_attempt_by_id(attempt_id)
+        self.assertIsNotNone(attempt['external_id'])
+
+        test_payload = Template(TEST_REVIEW_PAYLOAD).substitute(
+            attempt_code=attempt['attempt_code'],
+            external_id='mismatch'
+        )
+
+        response = self.client.post(
+            reverse('edx_proctoring.anonymous.proctoring_review_callback'),
+            data=test_payload,
+            content_type='application/json'
+        )
+        self.assertEqual(response.status_code, 400)
+
     def test_review_callback_get(self):
         """
         We don't support any http METHOD other than GET