Add basic LTI 1.3 support - #636

Preliminary launch steps are working, using updated code in our
django-lti-provider-example library.

CHANGES.txt

@@ -1,9 +1,12 @@
-1.0.0
+1.1.0
+==================
+* Add LTI 1.3 support
+
+1.0.0 (2023-10-26)
 ==================
 * Django 3 compatability
 * No longer testing against Django 2.2
 
-
 0.4.7
 ==================
 * Provide a default value for allow_ta_access setting.

lti_provider/urls.py

@@ -1,7 +1,11 @@
 from django.urls import re_path
 
-from lti_provider.views import LTIConfigView, LTILandingPage, LTIRoutingView, \
- LTICourseEnableView, LTIPostGrade, LTIFailAuthorization, LTICourseConfigure
+from lti_provider.views import (
+ LTIConfigView, LTILandingPage, LTIRoutingView,
+ LTICourseEnableView, LTIPostGrade, LTIFailAuthorization,
+ LTICourseConfigure,
+ login, launch, get_jwks, configure
+)
 
 
 urlpatterns = [
@@ -17,5 +21,12 @@
  re_path(r'^assignment/(?P<assignment_name>.*)/(?P<pk>\d+)/$',
  LTIRoutingView.as_view(), {}, 'lti-assignment-view'),
  re_path(r'^assignment/(?P<assignment_name>.*)/$',
- LTIRoutingView.as_view(), {}, 'lti-assignment-view')
+ LTIRoutingView.as_view(), {}, 'lti-assignment-view'),
+
+ # New pylti1.3 routes
+ re_path(r'^login/$', login, name='game-login'),
+ re_path(r'^launch/$', launch, name='game-launch'),
+ re_path(r'^jwks/$', get_jwks, name='jwks'),
+ re_path(r'^configure/(?P<launch_id>[\w-]+)/$', configure,
+ name='lti-configure')
 ]

lti_provider/views.py

@@ -1,4 +1,6 @@
 import time
+import os
+import pprint
 
 from django.conf import settings
 from django.contrib import messages
@@ -15,11 +17,16 @@
 from lti_provider.models import LTICourseContext
 from pylti.common import LTIPostMessageException, post_message
 
-
-try:
- from django.urls import reverse
-except ImportError:
- from django.core.urlresolvers import reverse
+from django.http import HttpResponse, HttpResponseForbidden, JsonResponse
+from django.shortcuts import render
+from django.views.decorators.http import require_POST
+from django.urls import reverse
+from pylti1p3.contrib.django import (
+ DjangoOIDCLogin, DjangoMessageLaunch, DjangoCacheDataStorage
+)
+from pylti1p3.deep_link_resource import DeepLinkResource
+from pylti1p3.tool_config import ToolConfJsonFile
+from pylti1p3.registration import Registration
 
 
 class LTIConfigView(TemplateView):
@@ -222,3 +229,109 @@ def post(self, request, *args, **kwargs):
  messages.add_message(request, messages.INFO, msg)
 
  return HttpResponseRedirect(redirect_url)
+
+
+#
+# New pylti1p3 funtionality below, adapted from pylti1.3-django-example
+#
+# https://github.com/dmitry-viskov/pylti1.3-django-example
+#
+class ExtendedDjangoMessageLaunch(DjangoMessageLaunch):
+
+ def validate_nonce(self):
+ """
+ Probably it is bug on "https://lti-ri.imsglobal.org":
+ site passes invalid "nonce" value during deep links launch.
+ Because of this in case of iss == http://imsglobal.org just
+ skip nonce validation.
+
+ """
+ iss = self.get_iss()
+ deep_link_launch = self.is_deep_link_launch()
+ if iss == "http://imsglobal.org" and deep_link_launch:
+ return self
+ return super().validate_nonce()
+
+
+def get_lti_config_path():
+ return os.path.join(settings.BASE_DIR, 'configs', 'config.json')
+
+
+def get_tool_conf():
+ tool_conf = ToolConfJsonFile(get_lti_config_path())
+ return tool_conf
+
+
+def get_jwk_from_public_key(key_name):
+ key_path = os.path.join(settings.BASE_DIR, 'configs', key_name)
+ f = open(key_path, 'r')
+ key_content = f.read()
+ jwk = Registration.get_jwk(key_content)
+ f.close()
+ return jwk
+
+
+def get_launch_data_storage():
+ return DjangoCacheDataStorage()
+
+
+def get_launch_url(request):
+ target_link_uri = request.POST.get(
+ 'target_link_uri', request.GET.get('target_link_uri'))
+ if not target_link_uri:
+ raise Exception('Missing "target_link_uri" param')
+ return target_link_uri
+
+
+def login(request):
+ tool_conf = get_tool_conf()
+ launch_data_storage = get_launch_data_storage()
+
+ oidc_login = DjangoOIDCLogin(
+ request, tool_conf, launch_data_storage=launch_data_storage)
+ target_link_uri = get_launch_url(request)
+ return oidc_login\
+ .enable_check_cookies()\
+ .redirect(target_link_uri)
+
+
+@require_POST
+def launch(request):
+ tool_conf = get_tool_conf()
+ launch_data_storage = get_launch_data_storage()
+ message_launch = ExtendedDjangoMessageLaunch(
+ request, tool_conf, launch_data_storage=launch_data_storage)
+ message_launch_data = message_launch.get_launch_data()
+ pprint.pprint(message_launch_data)
+
+ return render(request, 'game.html', {
+ 'page_title': 'Page Title',
+ 'is_deep_link_launch': message_launch.is_deep_link_launch(),
+ 'launch_data': message_launch.get_launch_data(),
+ 'launch_id': message_launch.get_launch_id(),
+ 'curr_user_name': message_launch_data.get('name', ''),
+ })
+
+
+def get_jwks(request):
+ tool_conf = get_tool_conf()
+ return JsonResponse(tool_conf.get_jwks(), safe=False)
+
+
+def configure(request, launch_id):
+ tool_conf = get_tool_conf()
+ launch_data_storage = get_launch_data_storage()
+ message_launch = ExtendedDjangoMessageLaunch.from_cache(
+ launch_id, request, tool_conf,
+ launch_data_storage=launch_data_storage)
+
+ if not message_launch.is_deep_link_launch():
+ return HttpResponseForbidden('Must be a deep link!')
+
+ launch_url = request.build_absolute_uri(reverse('game-launch'))
+
+ resource = DeepLinkResource()
+ resource.set_url(launch_url).set_title('Custom title!')
+
+ html = message_launch.get_deep_link().output_response_form([resource])
+ return HttpResponse(html)

setup.py

@@ -40,6 +40,7 @@
  "oauth2",
  "oauthlib",
  "pylti",
+ "pylti1p3",
  ],
  scripts=[],
  license="BSD",

test_reqs.txt

@@ -22,3 +22,12 @@ importlib-metadata<7.1 # for flake8
 entrypoints==0.4
 typing_extensions==4.10.0
 pyparsing==3.1.2
+
+certifi==2024.2.2 # requests
+idna==3.6 # requests
+charset_normalizer==3.3.2 # requests
+urllib3==2.2.1 # requests
+requests==2.31.0 # pylti1p3
+pyjwt==2.8.0 # pylti1p3
+jwcrypto==1.5.6 # pylti1p3
+pylti1p3==2.0.0