Fixed #109 -- Catch gateway errors

Should be updated to update the wizard form as well, so
no input field or next button is shown.

two_factor/templates/two_factor/core/setup.html

@@ -24,12 +24,20 @@ <h1>{% block title %}{% trans "Enable Two-Factor Authentication" %}{% endblock %
     <p>{% blocktrans %}Please enter the phone number you wish to be called on.
       This number will be validated in the next step. {% endblocktrans %}</p>
   {% elif wizard.steps.current == 'validation' %}
-    {% if device.method == 'call' %}
-      <p>{% blocktrans %}We are calling your phone right now, please enter the
-        digits you hear.{% endblocktrans %}</p>
-    {% elif device.method == 'sms' %}
-      <p>{% blocktrans %}We sent you a text message, please enter the tokens we
-        sent.{% endblocktrans %}</p>
+    {% if challenge_succeeded %}
+      {% if device.method == 'call' %}
+        <p>{% blocktrans %}We are calling your phone right now, please enter the
+          digits you hear.{% endblocktrans %}</p>
+      {% elif device.method == 'sms' %}
+        <p>{% blocktrans %}We sent you a text message, please enter the tokens we
+          sent.{% endblocktrans %}</p>
+      {% endif %}
+    {% else %}
+      <p class="alert alert-warning" role="alert">{% blocktrans %}We've
+        encountered an issue with the selected authentication method. Please
+        go back and verify that you entered your information correctly, try
+        again, or use a different authentication method instead. If the issue
+        persists, contact the site administrator.{% endblocktrans %}</p>
     {% endif %}
   {% elif wizard.steps.current == 'yubikey' %}
     <p>{% blocktrans %}To identify and verify your YubiKey, please insert a

two_factor/views/core.py

@@ -1,5 +1,6 @@
 from binascii import unhexlify
 from base64 import b32encode
+import logging
 
 from django.conf import settings
 from django.contrib.auth import login as login, REDIRECT_FIELD_NAME
@@ -40,6 +41,8 @@
                      backup_phones)
 from .utils import (IdempotentSessionWizardView, class_view_decorator)
 
+logger = logging.getLogger(__name__)
+
 
 @class_view_decorator(sensitive_post_parameters())
 @class_view_decorator(never_cache)
@@ -238,7 +241,12 @@ def render_next_step(self, form, **kwargs):
         """
         next_step = self.steps.next
         if next_step == 'validation':
-            self.get_device().generate_challenge()
+            try:
+                self.get_device().generate_challenge()
+                kwargs["challenge_succeeded"] = True
+            except:
+                logger.exception("Could not generate challenge")
+                kwargs["challenge_succeeded"] = False
         return super(SetupView, self).render_next_step(form, **kwargs)
 
     def done(self, form_list, **kwargs):