From b54622437248d1b50b3ecec11a681b2867a91f09 Mon Sep 17 00:00:00 2001
From: William Boman <william+github@redwill.se>
Date: Tue, 10 Apr 2018 15:21:37 +0200
Subject: [PATCH] send signals when blocking username or ip (#114)

---
 README.md           | 20 ++++++++++++++++++++
 defender/signals.py | 17 +++++++++++++++++
 defender/tests.py   | 26 ++++++++++++++++++++++++++
 defender/utils.py   |  3 +++
 4 files changed, 66 insertions(+)
 create mode 100644 defender/signals.py

diff --git a/README.md b/README.md
index b36eefc..2ae3c37 100644
--- a/README.md
+++ b/README.md
@@ -442,6 +442,26 @@ class BasicAuthenticationDefender(BasicAuthentication):
 
 To make it works add `BasicAuthenticationDefender` to `DEFAULT_AUTHENTICATION_CLASSES` above all other authentication methods in your `settings.py`.
 
+
+Django Signals
+--------------------
+
+`django-defender` will send signals when blocking a username or an IP address. To set up signal receiver functions:
+
+```python
+from django.dispatch import receiver
+from defender import signals
+
+@receiver(signals.username_block)
+def username_blocked(username, **kwargs):
+    print("%s was blocked!" % username)
+
+@receiver(signals.ip_block)
+def ip_blocked(ip_address, **kwargs):
+    print("%s was blocked!" % ip_address)
+
+```
+
 Running Tests
 =============
 
diff --git a/defender/signals.py b/defender/signals.py
new file mode 100644
index 0000000..4aaaec3
--- /dev/null
+++ b/defender/signals.py
@@ -0,0 +1,17 @@
+from django.dispatch import Signal
+
+username_block = Signal(providing_args=['username'])
+ip_block = Signal(providing_args=['ip_address'])
+
+class BlockSignal:
+    """
+    Providing a sender is mandatory when sending signals, hence
+    this empty sender class.
+    """
+    pass
+
+def send_username_block_signal(username):
+    username_block.send(sender=BlockSignal, username=username)
+
+def send_ip_block_signal(ip_address):
+    ip_block.send(sender=BlockSignal, ip_address=ip_address)
diff --git a/defender/tests.py b/defender/tests.py
index 59b708a..11f2d81 100644
--- a/defender/tests.py
+++ b/defender/tests.py
@@ -23,6 +23,7 @@ except ImportError:
 
 from . import utils
 from . import config
+from .signals import ip_block as ip_block_signal, username_block as username_block_signal
 from .connection import parse_redis_url, get_redis_connection
 from .decorators import watch_login
 from .models import AccessAttempt
@@ -875,6 +876,31 @@ class AccessAttemptTest(DefenderTestCase):
             self.assertEqual(data_out, [])
 
 
+class SignalTest(DefenderTestCase):
+    """ Test that signals are properly sent when blocking usernames and IPs.
+    """
+
+    def test_should_send_signal_when_blocking_ip(self):
+        self.blocked_ip = None
+
+        def handler(sender, ip_address, **kwargs):
+            self.blocked_ip = ip_address
+
+        ip_block_signal.connect(handler)
+        utils.block_ip('8.8.8.8')
+        self.assertEqual(self.blocked_ip, '8.8.8.8')
+
+    def test_should_send_signal_when_blocking_username(self):
+        self.blocked_username = None
+
+        def handler(sender, username, **kwargs):
+            self.blocked_username = username
+
+        username_block_signal.connect(handler)
+        utils.block_username('richard_hendricks')
+        self.assertEqual(self.blocked_username, 'richard_hendricks')
+
+
 class DefenderTestCaseTest(DefenderTestCase):
     """ Make sure that we're cleaning the cache between tests """
     key = 'test_key'
diff --git a/defender/utils.py b/defender/utils.py
index 43476ae..b94dba8 100644
--- a/defender/utils.py
+++ b/defender/utils.py
@@ -9,6 +9,7 @@ from django.core.exceptions import ValidationError
 from .connection import get_redis_connection
 from . import config
 from .data import store_login_attempt
+from .signals import send_username_block_signal, send_ip_block_signal
 
 REDIS_SERVER = get_redis_connection()
 
@@ -171,6 +172,7 @@ def block_ip(ip_address):
         REDIS_SERVER.set(key, 'blocked', config.COOLOFF_TIME)
     else:
         REDIS_SERVER.set(key, 'blocked')
+    send_ip_block_signal(ip_address)
 
 
 def block_username(username):
@@ -186,6 +188,7 @@ def block_username(username):
         REDIS_SERVER.set(key, 'blocked', config.COOLOFF_TIME)
     else:
         REDIS_SERVER.set(key, 'blocked')
+    send_username_block_signal(username)
 
 
 def record_failed_attempt(ip_address, username):