saml: Sanity-check configuration in both login and signup codepaths.

zerver/tests/test_auth_backends.py

@@ -1053,6 +1053,12 @@ class SAMLAuthBackendTest(SocialAuthBase):
             self.assertEqual(result.status_code, 302)
             self.assertEqual(result.url, self.CONFIG_ERROR_URL)
 
+            # Test the signup path too:
+            result = self.social_auth_test(account_data_dict, is_signup='1',
+                                           subdomain='zulip', next='/user_uploads/image')
+            self.assertEqual(result.status_code, 302)
+            self.assertEqual(result.url, self.CONFIG_ERROR_URL)
+
     def test_saml_auth_works_without_private_public_keys(self) -> None:
         with self.settings(SOCIAL_AUTH_SAML_SP_PUBLIC_CERT='', SOCIAL_AUTH_SAML_SP_PRIVATE_KEY=''):
             self.test_social_auth_success()

zerver/views/auth.py

@@ -38,7 +38,8 @@ from zerver.models import PreregistrationUser, UserProfile, remote_user_to_email
 from zerver.signals import email_on_new_login
 from zproject.backends import password_auth_enabled, dev_auth_enabled, \
     ldap_auth_enabled, ZulipLDAPConfigurationError, ZulipLDAPAuthBackend, \
-    AUTH_BACKEND_NAME_MAP, auth_enabled_helper, saml_auth_enabled
+    AUTH_BACKEND_NAME_MAP, auth_enabled_helper, saml_auth_enabled, SAMLAuthBackend, \
+    redirect_to_config_error
 from version import ZULIP_VERSION
 
 import jwt
@@ -162,9 +163,6 @@ def redirect_to_subdomain_login_url() -> HttpResponseRedirect:
     redirect_url = login_url + '?subdomain=1'
     return HttpResponseRedirect(redirect_url)
 
-def redirect_to_config_error(error_type: str) -> HttpResponseRedirect:
-    return HttpResponseRedirect("/config-error/%s" % (error_type,))
-
 def login_or_register_remote_user(request: HttpRequest, remote_username: str,
                                   user_profile: Optional[UserProfile], full_name: str='',
                                   mobile_flow_otp: Optional[str]=None,
@@ -355,15 +353,9 @@ def start_social_login(request: HttpRequest, backend: str, extra_arg: Optional[s
     backend_url = reverse('social:begin', args=[backend])
     extra_url_params = {}  # type: Dict[str, str]
     if backend == "saml":
-        obligatory_saml_settings_list = [
-            settings.SOCIAL_AUTH_SAML_SP_ENTITY_ID,
-            settings.SOCIAL_AUTH_SAML_ORG_INFO,
-            settings.SOCIAL_AUTH_SAML_TECHNICAL_CONTACT,
-            settings.SOCIAL_AUTH_SAML_SUPPORT_CONTACT,
-            settings.SOCIAL_AUTH_SAML_ENABLED_IDPS
-        ]
-        if any(not setting for setting in obligatory_saml_settings_list):
-            return redirect_to_config_error("saml")
+        result = SAMLAuthBackend.check_config()
+        if result is not None:
+            return result
 
         # This backend requires the name of the IdP (from the list of configured ones)
         # to be passed as the parameter.
@@ -387,6 +379,10 @@ def start_social_signup(request: HttpRequest, backend: str, extra_arg: Optional[
     backend_url = reverse('social:begin', args=[backend])
     extra_url_params = {}  # type: Dict[str, str]
     if backend == "saml":
+        result = SAMLAuthBackend.check_config()
+        if result is not None:
+            return result
+
         if not extra_arg or extra_arg not in settings.SOCIAL_AUTH_SAML_ENABLED_IDPS:
             logging.info("Attempted to initiate SAML authentication with wrong idp argument: {}"
                          .format(extra_arg))

zproject/backends.py

@@ -115,6 +115,9 @@ def any_social_backend_enabled(realm: Optional[Realm]=None) -> bool:
                             for social_auth_subclass in SOCIAL_AUTH_BACKENDS]
     return auth_enabled_helper(social_backend_names, realm)
 
+def redirect_to_config_error(error_type: str) -> HttpResponseRedirect:
+    return HttpResponseRedirect("/config-error/%s" % (error_type,))
+
 def require_email_format_usernames(realm: Optional[Realm]=None) -> bool:
     if ldap_auth_enabled(realm):
         if settings.LDAP_EMAIL_ATTR or settings.LDAP_APPEND_DOMAIN:
@@ -1233,6 +1236,20 @@ class SAMLAuthBackend(SocialAuthMixin, SAMLAuth):
 
         return result
 
+    @classmethod
+    def check_config(cls) -> Optional[HttpResponse]:
+        obligatory_saml_settings_list = [
+            settings.SOCIAL_AUTH_SAML_SP_ENTITY_ID,
+            settings.SOCIAL_AUTH_SAML_ORG_INFO,
+            settings.SOCIAL_AUTH_SAML_TECHNICAL_CONTACT,
+            settings.SOCIAL_AUTH_SAML_SUPPORT_CONTACT,
+            settings.SOCIAL_AUTH_SAML_ENABLED_IDPS
+        ]
+        if any(not setting for setting in obligatory_saml_settings_list):
+            return redirect_to_config_error("saml")
+
+        return None
+
 SocialBackendDictT = TypedDict('SocialBackendDictT', {
     'name': str,
     'display_name': str,