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WIP: Restricted OAuth Initial Design & Implementation #18117

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29 changes: 28 additions & 1 deletion lms/djangoapps/grades/api/views.py
Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,10 @@
from rest_framework.exceptions import AuthenticationFailed
from rest_framework.generics import GenericAPIView, ListAPIView
from rest_framework.response import Response

from rest_framework.permissions import IsAuthenticated
from edx_rest_framework_extensions.permissions import JWTRestrictedApplicationPermission
from edx_rest_framework_extensions.authentication import JwtAuthentication
from openedx.core.lib.api.authentication import OAuth2AuthenticationAllowInactiveUser
from courseware.access import has_access
from lms.djangoapps.courseware import courses
from lms.djangoapps.courseware.exceptions import CourseAccessRedirect
Expand Down Expand Up @@ -160,6 +163,19 @@ class UserGradeView(GradeViewMixin, GenericAPIView):
}]

"""
authentication_classes = (
JwtAuthentication,
OAuth2AuthenticationAllowInactiveUser,
)
permission_classes = (IsAuthenticated, JWTRestrictedApplicationPermission,)
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Please see https://github.com/edx/edx-platform/pull/17426
We need to use a common framework to make sure all endpoints enforce scopes. Otherwise, if a developer introduces a new endpoint that supports JwtAuthentication but forgets to add JWTRestrictedApplicationPermission, then malicious users can call that endpoint with a Restricted token without the appropriate scopes.

Once the work in the PR is complete, we should use the view_auth_classes decorator for this view.


# needed for passing JWTRestrictedApplicationPermission checks
# for RestrictedApplications (only). A RestrictedApplication can
# only call this method if it is allowed to receive a 'grades:read'
# scope
restricted_oauth_required = True
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Why is this boolean needed? If OAuth is always needed, then why does this view even add SessionAuthentication in its list?

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Reminder: this boolean can now be removed, right?

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yes, its removed now.

required_scopes = ['grades:read']

def get(self, request, course_id):
"""
Gets a course progress status.
Expand All @@ -171,6 +187,17 @@ def get(self, request, course_id):
Return:
A JSON serialized representation of the requesting user's current grade status.
"""
# See if the request has an explicit sattr(request, 'allowed_organizations'))
# which limits which OAuth2 clients can see the courses
# based on the association with a RestrictedApplication
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Rather than having a comment about this, consider Clean Code's recommendation to have self-describing code by creating a helper method with a self-describing name, such as "verify_content_organization_filter".

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Will remove the comments in the next commit

if hasattr(request, 'auth') and hasattr(request, 'filters'):
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To avoid namespace collisions by other apps storing values on the request object, we should add a namespace prefix to new fields we store on the shared request object. So filters should be prefixed by the app name that stores it.

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addressed in the latest commit.

course_key = CourseKey.from_string(course_id)
if course_key.org not in request.filters['content_org']:
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Since we are supporting different types of filters, we cannot assume that there's always a content_org filter. So we should check if a content_org filter exists, and if so, we should honor it. If it doesn't exist, we don't worry about filtering by content organization.

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addressed in the latest commit, good catch.

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You also need to check for the user=me filter, right?

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This code is for grades v0 and not for bulk grades; code validate current user earlier and throws valid exception. So, we don't need to validate user=me, we can discuss further if needed.

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Remainder: In the next PR, we will move the changes to Grades V1

return self.make_error_response(
status_code=status.HTTP_403_FORBIDDEN,
developer_message='The OAuth2 RestrictedApplication is not associated with org.',
error_code='course_org_not_associated_with_calling_application'
)

course = self._get_course(course_id, request.user, 'load')
if isinstance(course, Response):
Expand Down
20 changes: 18 additions & 2 deletions lms/envs/common.py
Original file line number Diff line number Diff line change
Expand Up @@ -498,20 +498,22 @@
OAUTH2_PROVIDER = {
'OAUTH2_VALIDATOR_CLASS': 'openedx.core.djangoapps.oauth_dispatch.dot_overrides.validators.EdxOAuth2Validator',
'REFRESH_TOKEN_EXPIRE_SECONDS': 20160,
'SCOPES_BACKEND_CLASS':'openedx.core.djangoapps.oauth_dispatch.scopes.DynamicScopes',
'SCOPES': {
'read': 'Read access',
'write': 'Write access',
'email': 'Know your email address',
# conform profile scope message that is presented to end-user
# to lms/templates/provider/authorize.html. This may be revised later.
'profile': 'Know your name and username',
'grades:read': 'Retrieve your grades for your enrolled courses'
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Note for later: Have this reviewed by someone on the edX Docs team.

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authorize.html needs to be updated so it presents the organization and filter type to the granting user. That is, the user needs to know that the requesting application will be limited to accessing grades only for its associated organization.

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Still working on it, we might need to override Authorize class & Url's from the provider library. Please update if you have other solution in addressing it.

},
'REQUEST_APPROVAL_PROMPT': 'auto_even_if_expired',
}
# This is required for the migrations in oauth_dispatch.models
# otherwise it fails saying this attribute is not present in Settings
OAUTH2_PROVIDER_APPLICATION_MODEL = 'oauth2_provider.Application'

##OAUTH2_PROVIDER_APPLICATION_MODEL = 'oauth2_provider.Application'
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Reminder: remove commented out code.

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done

OAUTH2_PROVIDER_APPLICATION_MODEL = 'oauth_dispatch.OauthRestrictedApplication'
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This will introduce backward compatibility concerns. We will need to provide some way to migrate existing Application models to the new ScopedApplication model.

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I think we definitely want to go this route (overriding the application model). We just want to make sure we have a rollout plan for this change in existing environments. It may be as simple as adding a data migration to this PR that copies the existing Application models to new ScopedApplication models. I just want to verify this is the "right" approach with our DevOps team.

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I checked with our DevOps team. We are good with adding a data migration that copies existing data from the old table to the new. This data migration would be adding after the existing migrations which add the new tables. Could you add that to this PR?

################################## TEMPLATE CONFIGURATION #####################################
# Mako templating
import tempfile
Expand Down Expand Up @@ -2402,6 +2404,8 @@ def _make_locale_paths(settings):
"reddit",
]

DEFAULT_JWT_ISSUER = 'test-issuer-1',
DEFAULT_RESTRICTED_JWT_ISSUER = 'test-issuer-2'
# JWT Settings
JWT_AUTH = {
# TODO Set JWT_SECRET_KEY to a secure value. By default, SECRET_KEY will be used.
Expand All @@ -2416,6 +2420,18 @@ def _make_locale_paths(settings):
'JWT_DECODE_HANDLER': 'edx_rest_framework_extensions.utils.jwt_decode_handler',
# Number of seconds before JWT tokens expire
'JWT_EXPIRATION': 30,
'JWT_ISSUERS': [
{
'ISSUER':'test-issuer-1',
'SECRET_KEY':'test-secret-key-1',
'AUDIENCE':'test-audience-1',
},
{
'ISSUER':'test-issuer-2',
'SECRET_KEY':'test-secret-key-2',
'AUDIENCE':'test-audience-2',
}
]
}

# The footer URLs dictionary maps social footer names
Expand Down
38 changes: 24 additions & 14 deletions openedx/core/djangoapps/oauth_dispatch/admin.py
Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,7 @@
from django.contrib.admin import ModelAdmin, site
from oauth2_provider import models

from .models import RestrictedApplication
from .models import RestrictedApplication, OauthRestrictOrganization, OauthRestrictedApplication
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How does OauthRestrictedApplication differ from RestrictedApplication? We need a better name.



def reregister(model_class):
Expand Down Expand Up @@ -52,17 +52,6 @@ class DOTRefreshTokenAdmin(ModelAdmin):
search_fields = [u'token', u'user__username', u'access_token__token']


@reregister(models.Application)
class DOTApplicationAdmin(ModelAdmin):
"""
Custom Application Admin
"""
list_display = [u'name', u'user', u'client_type', u'authorization_grant_type', u'client_id']
list_filter = [u'client_type', u'authorization_grant_type']
raw_id_fields = [u'user']
search_fields = [u'name', u'user__username', u'client_id']


@reregister(models.Grant)
class DOTGrantAdmin(ModelAdmin):
"""
Expand All @@ -79,7 +68,28 @@ class RestrictedApplicationAdmin(ModelAdmin):
"""
ModelAdmin for the Restricted Application
"""
list_display = [u'application']

list_display = [u'application', u'_org_associations']

site.register(RestrictedApplication, RestrictedApplicationAdmin)


@reregister(OauthRestrictedApplication)
class OauthRestrictedApplicationAdmin(ModelAdmin):
"""
ModelAdmin for the Restricted Application
"""
list_display = [u'name', u'user', u'client_type', u'authorization_grant_type', u'client_id']
list_filter = [u'client_type', u'authorization_grant_type']
raw_id_fields = [u'user']
search_fields = [u'name', u'user__username', u'client_id']


class OauthRestrictOrganizationAdmin(ModelAdmin):
"""
ModelAdmin for the Restricted Application
"""
list_display = [u'application','organization_type']
filter_horizontal = ('_org_associations',)

site.register(OauthRestrictOrganization, OauthRestrictOrganizationAdmin)

34 changes: 23 additions & 11 deletions openedx/core/djangoapps/oauth_dispatch/dot_overrides/validators.py
Original file line number Diff line number Diff line change
Expand Up @@ -13,9 +13,9 @@
from oauth2_provider.oauth2_validators import OAuth2Validator
from pytz import utc
from ratelimitbackend.backends import RateLimitMixin

from ..models import RestrictedApplication

from django.conf import settings
from ..models import RestrictedApplication, OauthRestrictedApplication
from openedx.core.djangoapps.oauth_dispatch.utils import is_oauth_scope_enforcement_enabled

@receiver(pre_save, sender=AccessToken)
def on_access_token_presave(sender, instance, *args, **kwargs): # pylint: disable=unused-argument
Expand All @@ -25,11 +25,8 @@ def on_access_token_presave(sender, instance, *args, **kwargs): # pylint: disab

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Need to update this docstring.

We do this as a pre-save hook on the ORM
"""

is_application_restricted = RestrictedApplication.objects.filter(application=instance.application).exists()
if is_application_restricted:
RestrictedApplication.set_access_token_as_expired(instance)

if not is_oauth_scope_enforcement_enabled():
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Nice name!

OauthRestrictedApplication.set_access_token_as_expired(instance)

# TODO: Remove Django 1.11 upgrade shim
# SHIM: Allow users that are inactive to still authenticate while keeping rate-limiting functionality.
Expand Down Expand Up @@ -112,8 +109,7 @@ def save_bearer_token(self, token, request, *args, **kwargs):

super(EdxOAuth2Validator, self).save_bearer_token(token, request, *args, **kwargs)

is_application_restricted = RestrictedApplication.objects.filter(application=request.client).exists()
if is_application_restricted:
if not is_oauth_scope_enforcement_enabled():
# Since RestrictedApplications will override the DOT defined expiry, so that access_tokens
# are always expired, we need to re-read the token from the database and then calculate the
# expires_in (in seconds) from what we stored in the database. This value should be a negative
Expand All @@ -122,7 +118,6 @@ def save_bearer_token(self, token, request, *args, **kwargs):
access_token = AccessToken.objects.get(token=token['access_token'])
utc_now = datetime.utcnow().replace(tzinfo=utc)
expires_in = (access_token.expires - utc_now).total_seconds()

# assert that RestrictedApplications only issue expired tokens
# blow up processing if we see otherwise
assert expires_in < 0
Expand All @@ -132,3 +127,20 @@ def save_bearer_token(self, token, request, *args, **kwargs):
# Restore the original request attributes
request.grant_type = grant_type
request.user = user

def validate_scopes(self, client_id, scopes, client, request, *args, **kwargs):
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As described in associate available scopes with applications, the more DOT standard way of doing this is to extend the SettingsScope backend and to set the new class as the value for the SCOPES_BACKEND_CLASS setting.

"""
Override the DOT implementation to add checks to make sure that a
RestrictedApplication is not granted scopes that it has not been
permitted to do
"""

restricted_application = RestrictedApplication.get_restricted_application(client)
if restricted_application:
# caller is restricted, so we must vet the allowed scopes for that restricted application
return set(scopes).issubset(restricted_application.allowed_scopes)

# not a restricted application, call into base implementation,
# which - basically - pulls the list of scopes from configuration settings as a global
# definition
return super(EdxOAuth2Validator, self).validate_scopes(client_id, scopes, client, request, *args, **kwargs)
Original file line number Diff line number Diff line change
@@ -0,0 +1,33 @@
# -*- coding: utf-8 -*-
# Generated by Django 1.11.12 on 2018-05-03 07:49
from __future__ import unicode_literals

from django.conf import settings
from django.db import migrations, models
import django.db.models.deletion


class Migration(migrations.Migration):

dependencies = [
('organizations', '0006_auto_20171207_0259'),
('oauth_dispatch', '0001_initial'),
]

operations = [
migrations.AddField(
model_name='restrictedapplication',
name='_allowed_scopes',
field=models.TextField(null=True),
),
migrations.AddField(
model_name='restrictedapplication',
name='_org_associations',
field=models.ForeignKey(default=b'', on_delete=django.db.models.deletion.CASCADE, to='organizations.Organization'),
),
migrations.AlterField(
model_name='restrictedapplication',
name='application',
field=models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, related_name='restricted_application', to=settings.OAUTH2_PROVIDER_APPLICATION_MODEL),
),
]
Original file line number Diff line number Diff line change
@@ -0,0 +1,54 @@
# -*- coding: utf-8 -*-
# Generated by Django 1.11.12 on 2018-05-15 17:50
from __future__ import unicode_literals

from django.conf import settings
from django.db import migrations, models
import django.db.models.deletion
import oauth2_provider.generators
import oauth2_provider.validators


class Migration(migrations.Migration):

dependencies = [
('organizations', '0006_auto_20171207_0259'),
migrations.swappable_dependency(settings.AUTH_USER_MODEL),
migrations.swappable_dependency(settings.OAUTH2_PROVIDER_APPLICATION_MODEL),
('oauth_dispatch', '0001_initial'),
]

operations = [
migrations.CreateModel(
name='OauthRestrictedApplication',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('client_id', models.CharField(db_index=True, default=oauth2_provider.generators.generate_client_id, max_length=100, unique=True)),
('redirect_uris', models.TextField(blank=True, help_text='Allowed URIs list, space separated', validators=[oauth2_provider.validators.validate_uris])),
('client_type', models.CharField(choices=[('confidential', 'Confidential'), ('public', 'Public')], max_length=32)),
('authorization_grant_type', models.CharField(choices=[('authorization-code', 'Authorization code'), ('implicit', 'Implicit'), ('password', 'Resource owner password-based'), ('client-credentials', 'Client credentials')], max_length=32)),
('client_secret', models.CharField(blank=True, db_index=True, default=oauth2_provider.generators.generate_client_secret, max_length=255)),
('name', models.CharField(blank=True, max_length=255)),
('skip_authorization', models.BooleanField(default=False)),
('allowed_scope', models.TextField(blank=True)),
('user', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='oauth_dispatch_oauthrestrictedapplication', to=settings.AUTH_USER_MODEL)),
],
options={
'abstract': False,
},
),
migrations.CreateModel(
name='OauthRestrictOrganization',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('organization_type', models.CharField(choices=[(b'content_provider', 'Content Provider'), (b'user_provider', 'User Provider')], default=b'content_provider', max_length=32)),
('_org_associations', models.ManyToManyField(to='organizations.Organization')),
('application', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.OAUTH2_PROVIDER_APPLICATION_MODEL)),
],
),
migrations.AlterField(
model_name='restrictedapplication',
name='application',
field=models.OneToOneField(on_delete=django.db.models.deletion.CASCADE, related_name='restricted_application', to=settings.OAUTH2_PROVIDER_APPLICATION_MODEL),
),
]
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