Change signin control from text list to buttons.

AUTHORS

@@ -141,3 +141,4 @@ William Desloge <william.desloge@ionis-group.com>
 Marco Re <mrc.re@tiscali.it>
 Jonas Jelten <jelten@in.tum.de>
 Christine Lytwynec <clytwynec@edx.org>
+John Cox <johncox@google.com>

CHANGELOG.rst

@@ -5,6 +5,8 @@ These are notable changes in edx-platform.  This is a rolling list of changes,
 in roughly chronological order, most recent first.  Add your entries at or near
 the top.  Include a label indicating the component affected.
 
+Common: Add extensible third-party auth module.
+
 Blades: Handle situation if no response were sent from XQueue to LMS in Matlab
 problem after Run Code button press. BLD-994.
 

common/djangoapps/student/views.py

@@ -16,6 +16,7 @@
 from django.contrib.auth.models import User, AnonymousUser
 from django.contrib.auth.decorators import login_required
 from django.contrib.auth.views import password_reset_confirm
+from django.contrib import messages
 from django.core.cache import cache
 from django.core.context_processors import csrf
 from django.core.mail import send_mail
@@ -85,6 +86,8 @@
     validate_password_dictionary
 )
 
+from third_party_auth import pipeline, provider
+
 log = logging.getLogger("edx.student")
 AUDIT_LOG = logging.getLogger("audit")
 
@@ -363,11 +366,16 @@ def signin_user(request):
     context = {
         'course_id': request.GET.get('course_id'),
         'enrollment_action': request.GET.get('enrollment_action'),
+        # Bool injected into JS to submit form if we're inside a running third-
+        # party auth pipeline; distinct from the actual instance of the running
+        # pipeline, if any.
+        'pipeline_running': 'true' if pipeline.running(request) else 'false',
         'platform_name': microsite.get_value(
             'platform_name',
             settings.PLATFORM_NAME
         ),
     }
+
     return render_to_response('login.html', context)
 
 
@@ -385,17 +393,34 @@ def register_user(request, extra_context=None):
 
     context = {
         'course_id': request.GET.get('course_id'),
+        'email': '',
         'enrollment_action': request.GET.get('enrollment_action'),
+        'name': '',
+        'running_pipeline': None,
         'platform_name': microsite.get_value(
             'platform_name',
             settings.PLATFORM_NAME
         ),
+        'selected_provider': '',
+        'username': '',
     }
+
     if extra_context is not None:
         context.update(extra_context)
 
     if context.get("extauth_domain", '').startswith(external_auth.views.SHIBBOLETH_DOMAIN_PREFIX):
         return render_to_response('register-shib.html', context)
+
+    # If third-party auth is enabled, prepopulate the form with data from the
+    # selected provider.
+    if settings.FEATURES.get('ENABLE_THIRD_PARTY_AUTH') and pipeline.running(request):
+        running_pipeline = pipeline.get(request)
+        current_provider = provider.Registry.get_by_backend_name(running_pipeline.get('backend'))
+        overrides = current_provider.get_register_form_data(running_pipeline.get('kwargs'))
+        overrides['running_pipeline'] = running_pipeline
+        overrides['selected_provider'] = current_provider.NAME
+        context.update(overrides)
+
     return render_to_response('register.html', context)
 
 
@@ -532,8 +557,17 @@ def dashboard(request):
         'language_options': language_options,
         'current_language': current_language,
         'current_language_code': cur_lang_code,
+        'user': user,
+        'duplicate_provider': None,
+        'logout_url': reverse(logout_user),
+        'platform_name': settings.PLATFORM_NAME,
+        'provider_states': [],
     }
 
+    if settings.FEATURES.get('ENABLE_THIRD_PARTY_AUTH'):
+        context['duplicate_provider'] = pipeline.get_duplicate_provider(messages.get_messages(request))
+        context['provider_user_states'] = pipeline.get_provider_user_states(user)
+
     return render_to_response('dashboard.html', context)
 
 
@@ -690,31 +724,70 @@ def accounts_login(request):
             return external_auth.views.course_specific_login(request, course_id)
 
     context = {
+        'pipeline_running': 'false',
         'platform_name': settings.PLATFORM_NAME,
     }
     return render_to_response('login.html', context)
 
 
 # Need different levels of logging
 @ensure_csrf_cookie
-def login_user(request, error=""):
+def login_user(request, error=""):  # pylint: disable-msg=too-many-statements,unused-argument
     """AJAX request to log in the user."""
-    if 'email' not in request.POST or 'password' not in request.POST:
-        return JsonResponse({
-            "success": False,
-            "value": _('There was an error receiving your login information. Please email us.'),  # TODO: User error message
-        })  # TODO: this should be status code 400  # pylint: disable=fixme
 
-    email = request.POST['email']
-    password = request.POST['password']
-    try:
-        user = User.objects.get(email=email)
-    except User.DoesNotExist:
-        if settings.FEATURES['SQUELCH_PII_IN_LOGS']:
-            AUDIT_LOG.warning(u"Login failed - Unknown user email")
-        else:
-            AUDIT_LOG.warning(u"Login failed - Unknown user email: {0}".format(email))
-        user = None
+    backend_name = None
+    email = None
+    password = None
+    redirect_url = None
+    response = None
+    running_pipeline = None
+    third_party_auth_requested = settings.FEATURES.get('ENABLE_THIRD_PARTY_AUTH') and pipeline.running(request)
+    third_party_auth_successful = False
+    trumped_by_first_party_auth = bool(request.POST.get('email')) or bool(request.POST.get('password'))
+    user = None
+
+    if third_party_auth_requested and not trumped_by_first_party_auth:
+        # The user has already authenticated via third-party auth and has not
+        # asked to do first party auth by supplying a username or password. We
+        # now want to put them through the same logging and cookie calculation
+        # logic as with first-party auth.
+        running_pipeline = pipeline.get(request)
+        username = running_pipeline['kwargs'].get('username')
+        backend_name = running_pipeline['backend']
+        requested_provider = provider.Registry.get_by_backend_name(backend_name)
+
+        try:
+            user = pipeline.get_authenticated_user(username, backend_name)
+            third_party_auth_successful = True
+        except User.DoesNotExist:
+            AUDIT_LOG.warning(
+                u'Login failed - user with username {username} has no social auth with backend_name {backend_name}'.format(
+                    username=username, backend_name=backend_name))
+            return JsonResponse({
+                "success": False,
+                # Translators: provider_name is the name of an external, third-party user authentication service (like
+                # Google or LinkedIn).
+                "value": _('There is no {platform_name} account associated with your {provider_name} account. Please use your {platform_name} credentials or pick another provider.').format(
+                    platform_name=settings.PLATFORM_NAME, provider_name=requested_provider.NAME)
+            })  # TODO: this should be a status code 401  # pylint: disable=fixme
+
+    else:
+
+        if 'email' not in request.POST or 'password' not in request.POST:
+            return JsonResponse({
+                "success": False,
+                "value": _('There was an error receiving your login information. Please email us.'),  # TODO: User error message
+            })  # TODO: this should be status code 400  # pylint: disable=fixme
+
+        email = request.POST['email']
+        password = request.POST['password']
+        try:
+            user = User.objects.get(email=email)
+        except User.DoesNotExist:
+            if settings.FEATURES['SQUELCH_PII_IN_LOGS']:
+                AUDIT_LOG.warning(u"Login failed - Unknown user email")
+            else:
+                AUDIT_LOG.warning(u"Login failed - Unknown user email: {0}".format(email))
 
     # check if the user has a linked shibboleth account, if so, redirect the user to shib-login
     # This behavior is pretty much like what gmail does for shibboleth.  Try entering some @stanford.edu
@@ -753,14 +826,17 @@ def login_user(request, error=""):
     # username so that authentication is guaranteed to fail and we can take
     # advantage of the ratelimited backend
     username = user.username if user else ""
-    try:
-        user = authenticate(username=username, password=password, request=request)
-    # this occurs when there are too many attempts from the same IP address
-    except RateLimitException:
-        return JsonResponse({
-            "success": False,
-            "value": _('Too many failed login attempts. Try again later.'),
-        })  # TODO: this should be status code 429  # pylint: disable=fixme
+
+    if not third_party_auth_successful:
+        try:
+            user = authenticate(username=username, password=password, request=request)
+        # this occurs when there are too many attempts from the same IP address
+        except RateLimitException:
+            return JsonResponse({
+                "success": False,
+                "value": _('Too many failed login attempts. Try again later.'),
+            })  # TODO: this should be status code 429  # pylint: disable=fixme
+
     if user is None:
         # tick the failed login counters if the user exists in the database
         if user_found_by_email_lookup and LoginFailures.is_feature_enabled():
@@ -801,7 +877,9 @@ def login_user(request, error=""):
 
         redirect_url = try_change_enrollment(request)
 
-        dog_stats_api.increment("common.student.successful_login")
+        if third_party_auth_successful:
+            redirect_url = pipeline.get_complete_url(backend_name)
+
         response = JsonResponse({
             "success": True,
             "redirect_url": redirect_url,
@@ -1027,16 +1105,20 @@ def _do_create_account(post_vars):
 
 
 @ensure_csrf_cookie
-def create_account(request, post_override=None):
+def create_account(request, post_override=None):  # pylint: disable-msg=too-many-statements
     """
     JSON call to create new edX account.
     Used by form in signup_modal.html, which is included into navigation.html
     """
-    js = {'success': False}
+    js = {'success': False}  # pylint: disable-msg=invalid-name
 
     post_vars = post_override if post_override else request.POST
     extra_fields = getattr(settings, 'REGISTRATION_EXTRA_FIELDS', {})
 
+    if settings.FEATURES.get('ENABLE_THIRD_PARTY_AUTH') and pipeline.running(request):
+        post_vars = dict(post_vars.items())
+        post_vars.update({'password': pipeline.make_random_password()})
+
     # if doing signup for an external authorization, then get email, password, name from the eamap
     # don't use the ones from the form, since the user could have hacked those
     # unless originally we didn't get a valid email or name from the external auth
@@ -1234,9 +1316,17 @@ def create_account(request, post_override=None):
             login_user.save()
             AUDIT_LOG.info(u"Login activated on extauth account - {0} ({1})".format(login_user.username, login_user.email))
 
+    dog_stats_api.increment("common.student.account_created")
+    redirect_url = try_change_enrollment(request)
+
+    # Resume the third-party-auth pipeline if necessary.
+    if settings.FEATURES.get('ENABLE_THIRD_PARTY_AUTH') and pipeline.running(request):
+        running_pipeline = pipeline.get(request)
+        redirect_url = pipeline.get_complete_url(running_pipeline['backend'])
+
     response = JsonResponse({
         'success': True,
-        'redirect_url': try_change_enrollment(request),
+        'redirect_url': redirect_url,
     })
 
     # set the login cookie for the edx marketing site

common/djangoapps/third_party_auth/middleware.py

@@ -0,0 +1,18 @@
+"""Middleware classes for third_party_auth."""
+
+from social.apps.django_app.middleware import SocialAuthExceptionMiddleware
+
+from . import pipeline
+
+
+class ExceptionMiddleware(SocialAuthExceptionMiddleware):
+    """Custom middleware that handles conditional redirection."""
+
+    def get_redirect_uri(self, request, exception):
+        # Safe because it's already been validated by
+        # pipeline.parse_query_params. If that pipeline step ever moves later
+        # in the pipeline stack, we'd need to validate this value because it
+        # would be an injection point for attacker data.
+        auth_entry = request.session.get(pipeline.AUTH_ENTRY_KEY)
+        # Fall back to django settings's SOCIAL_AUTH_LOGIN_ERROR_URL.
+        return '/' + auth_entry if auth_entry else super(ExceptionMiddleware, self).get_redirect_uri(request, exception)