django-defender 0.1

redis based Django app that locks out users after too many failed login attempts.

django-defender
===============

A simple Django reusable app that blocks people from brute forcing login
attempts. The goal is to make this as fast as possible, so that we do not
slow down the login attempts.

We will use a cache so that it doesn't have to hit the database in order to
check the database on each login attempt. The first version will be based on
Redis, but the goal is to make this configurable so that people can use what
they want for a backend, so it is configurable.

Build status
------------

[](https://travis-ci.org/kencochrane/django-defender) [](https://coveralls.io/r/kencochrane/django-defender)[](https://landscape.io/github/kencochrane/django-defender/master)

Sites using Defender:
=====================
- https://hub.docker.com

0.1 Features
============

- Log all login attempts to the database
- support for reverse proxies with different headers for IP addresses
- rate limit based on:
- username
- ip address
- use redis for the blacklist
- configuration
- redis server
- host
- port
- database
- password
- key_prefix
- block length
- number of incorrect attempts before block
- 95% code coverage
- full documentation
- admin pages
- list of blocked usernames and ip's
- ability to unblock people
- list of recent login attempts

Long term goals
===============

- pluggable backends, so people can use something other then redis.
- email users when their account is blocked
- add a whitelist for username and ip's that we will never block (admin's, etc)
- add a permanent black list
- ip address
- scan for known proxy ip's and don't block requests coming from those
(improve the chances that a good IP is blocked)
- add management command to prune old (configurable) login attempts.

Performance:
============
The goal of defender is to make it as fast as possible so that it doesn't slow
down the login process. In order to make sure our goals are met we need a way
to test the application to make sure we are on the right track. The best
way to do this is to compare how fast a normal Django login takes with defender
and django-axes.

The normal django login, would be our baseline, and we expect it to be the
fastest of the 3 methods, because there are no additional checks happening.

The defender login would most likely be slower then the django login, and
hopefully faster then the django-axes login. The goal is to make it as little
of a difference between the regular raw login, and defender.

The django-axes login speed, will probably be the slowest of the three since it
does more checks and does a lot of database queries.

The best way to determine the speed of a login is to do a load test against an
application with each setup, and compare the login times for each type.

Types of Load tests
-------------------
In order to make sure we cover all the different types of logins, in our load
test we need to have more then one test.

1. All success:
- We will do a load test with nothing but successful logins
2. Mixed: some success some failure:
- We will load test with some successful logins and some failures to see how
the failure effect the performance.
3. All Failures:
- We will load test with all failure logins and see the difference in
performance.

We will need a sample application that we can use for the load test, with the
only difference is the configuration where we either load defender, axes, or
none of them.

We can use a hosted load testing service, or something like jmeter. Either way
we need to be consistent for all of the tests. If we use jmeter, we should have
our jmeter configuration for others to run the tests on their own.

Results
-------
We will post the results here. We will explain each test, and show the results
along with some charts.


Why not django-axes
===================

django-axes is great but it puts everything in the database, and this causes
a bottle neck when you have a lot of data. It slows down the auth requests by
as much as 200-300ms. This might not be much for some sites, but for others it
is too long.

This started out as a fork of django-axes, and is using as much of their code
as possible, and removing the parts not needed, and speeding up the lookups
to improve the login.

requirements
============

- django: 1.6.x, 1.7.x
- redis
- python: 2.6.x, 2.7.x, 3.3.x, 3.4.x, PyPy

How it works
============

1. When someone tries to login, we first check to see if they are currently
blocked. We check the username they are trying to use, as well as the IP
address. If they are blocked, goto step 5. If not blocked go to step 2.

2. They are not blocked, so we check to see if the login was valid. If valid
go to step 6. If not valid go to step 3.

3. Login attempt wasn't valid. Add their username and IP address for this
attempt to the cache. If this brings them over the limit, add them to the
blocked list, and then goto step 5. If not over the limit goto step 4.

4. login was invalid, but not over the limit. Send them back to the login screen
to try again.

5. User is blocked: Send them to the blocked page, telling them they are
blocked, and give an estimate on when they will be unblocked.

6. Login is valid. Reset any failed login attempts, and forward to their
destination.


Cache backend:
==============

cache keys:
-----------

Counters:
- prefix:failed:ip:[ip] (count, TTL)
- prefix:failed:username:[username] (count, TTL)

Booleans (if present it is blocked):
- prefix:blocked:ip:[ip] (true, TTL)
- prefix:blocked:username:[username] (true, TTL)

Installing Django-defender
==========================

Download code, and run setup.

```
$ pip install django-defender

or

$ python setup.py install

or

$ pip install -e git+http://github.com/kencochrane/django-defender.git#egg=django_defender-dev

```

First of all, you must add this project to your list of ``INSTALLED_APPS`` in
``settings.py``::

```
INSTALLED_APPS = (
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.sites',
...
'defender',
...
)
```

Next, install the ``FailedLoginMiddleware`` middleware::

```
MIDDLEWARE_CLASSES = (
'django.middleware.common.CommonMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'defender.middleware.FailedLoginMiddleware'
)
```

If you want to manage the blocked users via the Django admin, then add the
following to your ``urls.py``

```
urlpatterns = patterns(
'',
(r'^admin/', include(admin.site.urls)), # normal admin
(r'^admin/defender/', include('defender.urls')), # defender admin
# your own patterns follow…
)
```


Admin Pages:
------------


Database tables:
----------------

You will need to create tables in your database that are necessary
for operation.

If you're using Django 1.7.x:
```bash
python manage.py migrate defender
```

On versions of Django prior to 1.7, you might use South (version >= 1.0).
```bash
python manage.py migrate defender
```

If you're not using South, a normal syncdb will work:
```bash
python manage.py syncdb
```

Customizing Defender
--------------------

You have a couple options available to you to customize ``django-defender`` a bit.
These should be defined in your ``settings.py`` file.

* ``DEFENDER_LOGIN_FAILURE_LIMIT``: Int: The number of login attempts allowed before a
record is created for the failed logins. [Default: ``3``]
* ``DEFENDER_USE_USER_AGENT``: Boolean: If ``True``, lock out / log based on an IP address
AND a user agent. This means requests from different user agents but from
the same IP are treated differently. [Default: ``False``]
* ``DEFENDER_COOLOFF_TIME``: Int: If set, defines a period of inactivity after which
old failed login attempts will be forgotten. An integer, will be interpreted as a
number of seconds. If ``0``, the locks will not expire. [Default: ``300``]
* ``DEFENDER_LOCKOUT_TEMPLATE``: String: [Default: ``None``] If set, specifies a template to render when a user is locked out. Template receives the following context variables:
- ``cooloff_time_seconds``: The cool off time in seconds
- ``cooloff_time_minutes``: The cool off time in minutes
- ``failure_limit``: The number of failures before you get blocked.
* ``DEFENDER_USERNAME_FORM_FIELD``: String: the name of the form field that contains your
users usernames. [Default: ``username``]
* ``DEFENDER_REVERSE_PROXY_HEADER``: String: the name of the http header with your
reverse proxy IP address [Default: ``HTTP_X_FORWARDED_FOR``]
* ``DEFENDER_CACHE_PREFIX``: String: The cache prefix for your defender keys.
[Default: ``defender``]
* ``DEFENDER_LOCKOUT_URL``: String: The URL you want to redirect to if someone is
locked out.
* ``DEFENDER_REDIS_URL``: String: the redis url for defender.
[Default: ``redis://localhost:6379/0``]
(Example with password: ``redis://:mypassword@localhost:6379/0``)
* ``DEFENDER_USE_CELERY``: Boolean: If you want to use Celery to store the login
attempt to the database, set to True. If False, it is saved inline.
[Default: ``False``]

Running Tests
=============

Tests can be run, after you clone the repository and having Django installed,
like:

```
$ PYTHONPATH=$PYTHONPATH:$PWD django-admin.py test defender --settings=defender.test_settings
```

With Code coverage:

```
PYTHONPATH=$PYTHONPATH:$PWD coverage run --source=defender $(which django-admin.py) test defender --settings=defender.test_settings
```