[LTI Provider] WIP: Simple LTI authentication

lms/djangoapps/lti_provider/migrations/0001_create_lti_consumer_model.py

@@ -0,0 +1,37 @@
+# -*- coding: utf-8 -*-
+# pylint: disable=invalid-name, missing-docstring, unused-argument, unused-import, line-too-long
+from south.utils import datetime_utils as datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Adding model 'LtiConsumer'
+        db.create_table('lti_provider_lticonsumer', (
+            ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('consumer_name', self.gf('django.db.models.fields.CharField')(max_length=255)),
+            ('consumer_key', self.gf('django.db.models.fields.CharField')(unique=True, max_length=32, db_index=True)),
+            ('consumer_secret', self.gf('django.db.models.fields.CharField')(unique=True, max_length=32)),
+        ))
+        db.send_create_signal('lti_provider', ['LtiConsumer'])
+
+
+    def backwards(self, orm):
+        # Deleting model 'LtiConsumer'
+        db.delete_table('lti_provider_lticonsumer')
+
+
+    models = {
+        'lti_provider.lticonsumer': {
+            'Meta': {'object_name': 'LtiConsumer'},
+            'consumer_key': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '32', 'db_index': 'True'}),
+            'consumer_name': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
+            'consumer_secret': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '32'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'})
+        }
+    }
+
+    complete_apps = ['lti_provider']

lms/djangoapps/lti_provider/migrations/0002_create_lti_user_model.py

@@ -0,0 +1,43 @@
+# -*- coding: utf-8 -*-
+from south.utils import datetime_utils as datetime
+from south.db import db
+from south.v2 import SchemaMigration
+from django.db import models
+
+
+class Migration(SchemaMigration):
+
+    def forwards(self, orm):
+        # Adding model 'LtiUser'
+        db.create_table('lti_provider_ltiuser', (
+            ('id', self.gf('django.db.models.fields.AutoField')(primary_key=True)),
+            ('lti_user_id', self.gf('django.db.models.fields.CharField')(unique=True, max_length=255, db_index=True)),
+            ('edx_user_id', self.gf('django.db.models.fields.CharField')(unique=True, max_length=30)),
+            ('edx_password', self.gf('django.db.models.fields.CharField')(max_length=255)),
+        ))
+        db.send_create_signal('lti_provider', ['LtiUser'])
+
+
+    def backwards(self, orm):
+        # Deleting model 'LtiUser'
+        db.delete_table('lti_provider_ltiuser')
+
+
+    models = {
+        'lti_provider.lticonsumer': {
+            'Meta': {'object_name': 'LtiConsumer'},
+            'consumer_key': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '32', 'db_index': 'True'}),
+            'consumer_name': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
+            'consumer_secret': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '32'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'})
+        },
+        'lti_provider.ltiuser': {
+            'Meta': {'object_name': 'LtiUser'},
+            'edx_password': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
+            'edx_user_id': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '30'}),
+            'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
+            'lti_user_id': ('django.db.models.fields.CharField', [], {'unique': 'True', 'max_length': '255', 'db_index': 'True'})
+        }
+    }
+
+    complete_apps = ['lti_provider']

lms/djangoapps/lti_provider/models.py

@@ -1,5 +1,12 @@
 """
 Database models for the LTI provider feature.
+
+This app uses migrations. If you make changes to this model, be sure to create
+an appropriate migration file and check it in at the same time as your model
+changes. To do that,
+
+1. Go to the edx-platform dir
+2. ./manage.py lms schemamigration lti_provider --auto "description" --settings=devstack
 """
 from django.db import models
 from django.dispatch import receiver
@@ -13,8 +20,14 @@ class LtiConsumer(models.Model):
     specific settings, such as the OAuth key/secret pair and any LTI fields
     that must be persisted.
     """
-    key = models.CharField(max_length=32, unique=True, db_index=True)
-    secret = models.CharField(max_length=32, unique=True)
+    consumer_name = models.CharField(max_length=255)
+    consumer_key = models.CharField(max_length=32, unique=True, db_index=True)
+    consumer_secret = models.CharField(max_length=32, unique=True)
+
+
+class LtiUser(models.Model):
+    lti_user_id = models.CharField(max_length=255, unique=True, db_index=True)
+    edx_user_id = models.CharField(max_length=30, unique=True)
 
 
 @receiver(SCORE_CHANGED)

lms/djangoapps/lti_provider/signature_validator.py

@@ -79,7 +79,7 @@ def validate_client_key(self, client_key, request):
 
         :return: True if the key is valid, False if it is not.
         """
-        return LtiConsumer.objects.filter(key=client_key).count() == 1
+        return LtiConsumer.objects.filter(consumer_key=client_key).count() == 1
 
     def get_client_secret(self, client_key, request):
         """
@@ -90,7 +90,7 @@ def get_client_secret(self, client_key, request):
         present, or None if the key does not exist in the database.
         """
         try:
-            return LtiConsumer.objects.get(key=client_key).secret
+            return LtiConsumer.objects.get(consumer_key=client_key).consumer_secret
         except ObjectDoesNotExist:
             return None
 

lms/djangoapps/lti_provider/tests/test_signature_validator.py

@@ -78,7 +78,7 @@ def test_validate_existing_key(self):
         Verify that validate_client_key succeeds if the client key exists in the
         database
         """
-        LtiConsumer.objects.create(key='client_key', secret='client_secret')
+        LtiConsumer.objects.create(consumer_key='client_key', consumer_secret='client_secret')
         self.assertTrue(SignatureValidator().validate_client_key('client_key', None))
 
     def test_validate_missing_key(self):
@@ -93,7 +93,7 @@ def test_get_existing_client_secret(self):
         Verify that get_client_secret returns the right value if the key is in
         the database
         """
-        LtiConsumer.objects.create(key='client_key', secret='client_secret')
+        LtiConsumer.objects.create(consumer_key='client_key', consumer_secret='client_secret')
         secret = SignatureValidator().get_client_secret('client_key', None)
         self.assertEqual(secret, 'client_secret')
 

lms/djangoapps/lti_provider/tests/test_views.py

@@ -8,6 +8,7 @@
 
 from lti_provider import views
 from lti_provider.signature_validator import SignatureValidator
+from opaque_keys.edx.keys import CourseKey, UsageKey
 from student.tests.factories import UserFactory
 
 
@@ -22,10 +23,11 @@
     'oauth_nonce': u'OAuth Nonce',
 }
 
-
+COURSE_KEY = CourseKey.from_string('some/course/id')
+USAGE_KEY = UsageKey.from_string('i4x://some/course/problem/uuid').map_into_course(COURSE_KEY)
 COURSE_PARAMS = {
-    'course_id': 'CourseID',
-    'usage_id': 'UsageID'
+    'course_key': COURSE_KEY,
+    'usage_key': USAGE_KEY
 }
 
 
@@ -72,7 +74,7 @@ def test_valid_launch(self, render):
         Verifies that the LTI launch succeeds when passed a valid request.
         """
         request = build_launch_request()
-        views.lti_launch(request, COURSE_PARAMS['course_id'], COURSE_PARAMS['usage_id'])
+        views.lti_launch(request, str(COURSE_PARAMS['course_key']), str(COURSE_PARAMS['usage_key']))
         render.assert_called_with(request, ALL_PARAMS)
 
     def launch_with_missing_parameter(self, missing_param):
@@ -112,10 +114,10 @@ def test_session_contents_after_launch(self, _run):
         properly stored in the session
         """
         request = build_launch_request()
-        views.lti_launch(request, COURSE_PARAMS['course_id'], COURSE_PARAMS['usage_id'])
+        views.lti_launch(request, str(COURSE_PARAMS['course_key']), str(COURSE_PARAMS['usage_key']))
         session = request.session[views.LTI_SESSION_KEY]
-        self.assertEqual(session['course_id'], 'CourseID', 'Course ID not set in the session')
-        self.assertEqual(session['usage_id'], 'UsageID', 'Usage ID not set in the session')
+        self.assertEqual(session['course_key'], COURSE_KEY, 'Course key not set in the session')
+        self.assertEqual(session['usage_key'], USAGE_KEY, 'Usage key not set in the session')
         for key in views.REQUIRED_PARAMETERS:
             self.assertEqual(session[key], request.POST[key], key + ' not set in the session')
 
@@ -126,7 +128,9 @@ def test_redirect_for_non_authenticated_user(self):
         URL
         """
         request = build_launch_request(False)
-        response = views.lti_launch(request, None, None)
+        response = views.lti_launch(
+            request, str(COURSE_PARAMS['course_key']), str(COURSE_PARAMS['usage_key'])
+        )
         self.assertEqual(response.status_code, 302)
         self.assertEqual(response['Location'], '/accounts/login?next=/lti_provider/lti_run')
 
@@ -170,7 +174,7 @@ def test_forbidden_if_session_incomplete(self):
         Verifies that the lti_run view returns a Forbidden status if the session
         is missing any of the required LTI parameters or course information.
         """
-        extra_keys = ['course_id', 'usage_id']
+        extra_keys = ['course_key', 'usage_key']
         for key in views.REQUIRED_PARAMETERS + extra_keys:
             request = build_run_request()
             del request.session[views.LTI_SESSION_KEY][key]
@@ -208,7 +212,6 @@ def setUp(self):
         self.module_mock = self.setup_patch('lti_provider.views.get_module_by_usage_id', (self.module_instance, None))
         self.access_mock = self.setup_patch('lti_provider.views.has_access', 'StaffAccess')
         self.course_mock = self.setup_patch('lti_provider.views.get_course_with_access', 'CourseWithAccess')
-        self.key_mock = self.setup_patch('lti_provider.views.CourseKey.from_string', 'CourseKey')
 
     def setup_patch(self, function_name, return_value):
         """
@@ -228,21 +231,13 @@ def test_valid_launch(self):
         response = views.render_courseware(request, ALL_PARAMS.copy())
         self.assertEqual(response, 'Rendered page')
 
-    def test_course_key(self):
-        """
-        Verify that the correct course key is requested
-        """
-        request = build_run_request()
-        views.render_courseware(request, ALL_PARAMS.copy())
-        self.key_mock.assert_called_with(ALL_PARAMS['course_id'])
-
     def test_course_with_access(self):
         """
         Verify that get_course_with_access is called with the right parameters
         """
         request = build_run_request()
         views.render_courseware(request, ALL_PARAMS.copy())
-        self.course_mock.assert_called_with(request.user, 'load', 'CourseKey')
+        self.course_mock.assert_called_with(request.user, 'load', COURSE_KEY)
 
     def test_has_access(self):
         """
@@ -258,7 +253,7 @@ def test_get_module(self):
         """
         request = build_run_request()
         views.render_courseware(request, ALL_PARAMS.copy())
-        self.module_mock.assert_called_with(request, ALL_PARAMS['course_id'], ALL_PARAMS['usage_id'])
+        self.module_mock.assert_called_with(request, str(ALL_PARAMS['course_key']), str(ALL_PARAMS['usage_key']))
 
     def test_render(self):
         """
@@ -278,7 +273,7 @@ def test_context(self):
             'disable_footer': True,
             'disable_tabs': True,
             'staff_access': 'StaffAccess',
-            'xqa_server': 'http://your_xqa_server.com',
+            'xqa_server': 'http://example.com/xqa',
         }
         request = build_run_request()
         views.render_courseware(request, ALL_PARAMS.copy())

lms/djangoapps/lti_provider/users.py

@@ -0,0 +1,42 @@
+import string
+import random
+import uuid
+
+from django.contrib.auth import authenticate, login, get_backends
+from django.contrib.auth.models import User
+from lti_provider.models import LtiUser
+
+
+def create_lti_user(params):
+    lti_user_id = params['user_id']
+    edx_user_id = generate_random_edx_username()
+    edx_password = uuid.uuid4()
+
+    edx_user = User.objects.create_user(
+        username=edx_user_id,
+        password=edx_password,
+        email='{}@lti.example.com'.format(edx_user_id)
+    )
+    edx_user.save()
+
+    lti_user = LtiUser(
+        lti_user_id=lti_user_id,
+        edx_user_id=edx_user_id,
+    )
+    lti_user.save()
+    return lti_user
+
+
+def switch_user(request, lti_user):
+    user = User.objects.get(username=lti_user.edx_user_id)
+    user.backend = 'nobody'
+    if user:
+        login(request, user)
+
+
+def generate_random_edx_username():
+    allowable_chars = string.ascii_letters + string.digits
+    username = ''
+    for _i in range(30):
+        username = username + random.SystemRandom().choice(allowable_chars)
+    return username