.

physics/migrations/0015_exam_valid_users.py

@@ -0,0 +1,19 @@
+# Generated by Django 3.2.8 on 2021-12-11 13:01
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('generic', '0015_ciduser_ciduserexam'),
+        ('physics', '0014_alter_exam_open_access'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='exam',
+            name='valid_users',
+            field=models.ManyToManyField(blank=True, related_name='physics_exams', to='generic.CidUser'),
+        ),
+    ]

physics/models.py

@@ -12,7 +12,7 @@ from django.utils.translation import ugettext_lazy as _
 
 from sortedm2m.fields import SortedManyToManyField
 
-from generic.models import ExamBase, QuestionNote
+from generic.models import CidUser, ExamBase, QuestionNote
 
 import reversion
 
@@ -154,6 +154,7 @@ class Exam(ExamBase):
                                     help_text='Author of exam',
                                     related_name="physics_exam_author")
 
+    valid_users = models.ManyToManyField(CidUser, blank=True, related_name="physics_exams")
 
 
 @reversion.register

physics/views.py

@@ -315,13 +315,19 @@ def exam_finish(request, pk, cid):
     )
 
 
-def exam_take(request, pk, sk, cid):
+def exam_take(request, pk, sk, cid, passcode=None):
 
     exam = get_object_or_404(Exam, pk=pk)
 
     if not exam.active:
         raise Http404("Exam not found")
 
+    if exam.valid_users is not None:
+        user = exam.valid_users.filter(cid=cid)
+
+        if not user or user.passcode != passcode:
+            raise Http404("Exam not found")
+
     question = exam.exam_questions.all()[sk]
 
     exam_length = len(exam.exam_questions.all())