text: # ***** BEGIN LICENSE BLOCK *****
  # Version: MPL 1.1/GPL 2.0/LGPL 2.1
  # 
  # The contents of this file are subject to the Mozilla Public License Version
  # 1.1 (the "License"); you may not use this file except in compliance with
  # the License. You may obtain a copy of the License at
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  # 
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  # WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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  # License.
  # 
  # The Original Code is Mozilla Sheriff Duty.
  # 
  # The Initial Developer of the Original Code is Mozilla Corporation.
  # Portions created by the Initial Developer are Copyright (C) 2011
  # the Initial Developer. All Rights Reserved.
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  # Contributor(s):
  # 
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  # either the GNU General Public License Version 2 or later (the "GPL"), or
  # the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  # in which case the provisions of the GPL or the LGPL are applicable instead
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  # ***** END LICENSE BLOCK *****
  
  from django.contrib.auth.models import User
  
  
  class EmailOrUsernameModelBackend(object):
  
      supports_object_permissions = False
      supports_anonymous_user = False
      supports_inactive_user = False
  
      def authenticate(self, username=None, password=None):
          if '@' in username:
              kwargs = {'email__iexact': username}
          else:
              kwargs = {'username': username}
          try:
              user = User.objects.get(**kwargs)
              if user.check_password(password):
                  return user
          except User.DoesNotExist:
              return None
  
      def get_user(self, user_id):
          try:
              return User.objects.get(pk=user_id)
          except User.DoesNotExist:  # pragma: no cover
              return None
  