Increased the default PBKDF2 iterations.

django/contrib/auth/hashers.py

@@ -226,7 +226,7 @@ class PBKDF2PasswordHasher(BasePasswordHasher):
     safely but you must rename the algorithm if you change SHA256.
     """
     algorithm = "pbkdf2_sha256"
-    iterations = 20000
+    iterations = 24000
     digest = hashlib.sha256
 
     def encode(self, password, salt, iterations=None):

django/contrib/auth/tests/test_hashers.py

@@ -46,7 +46,7 @@ class TestUtilsHashPass(SimpleTestCase):
     def test_pkbdf2(self):
         encoded = make_password('lètmein', 'seasalt', 'pbkdf2_sha256')
         self.assertEqual(encoded,
-            'pbkdf2_sha256$20000$seasalt$oBSd886ysm3AqYun62DOdin8YcfbU1z9cksZSuLP9r0=')
+            'pbkdf2_sha256$24000$seasalt$V9DfCAVoweeLwxC/L2mb+7swhzF0XYdyQMqmusZqiTc=')
         self.assertTrue(is_password_usable(encoded))
         self.assertTrue(check_password('lètmein', encoded))
         self.assertFalse(check_password('lètmeinz', encoded))
@@ -210,14 +210,14 @@ class TestUtilsHashPass(SimpleTestCase):
         hasher = PBKDF2PasswordHasher()
         encoded = hasher.encode('lètmein', 'seasalt2')
         self.assertEqual(encoded,
-            'pbkdf2_sha256$20000$seasalt2$Flpve/uAcyo6+IFI6YAhjeABGPVbRQjzHDxRhqxewgw=')
+            'pbkdf2_sha256$24000$seasalt2$TUDkfilKHVC7BkaKSZgIKhm0aTtXlmcw/5C1FeS/DPk=')
         self.assertTrue(hasher.verify('lètmein', encoded))
 
     def test_low_level_pbkdf2_sha1(self):
         hasher = PBKDF2SHA1PasswordHasher()
         encoded = hasher.encode('lètmein', 'seasalt2')
         self.assertEqual(encoded,
-            'pbkdf2_sha1$20000$seasalt2$pJt86NmjAweBY1StBvxCu7l1o9o=')
+            'pbkdf2_sha1$24000$seasalt2$L37ETdd9trqrsJDwapU3P+2Edhg=')
         self.assertTrue(hasher.verify('lètmein', encoded))
 
     def test_upgrade(self):

docs/releases/1.9.txt

@@ -38,7 +38,10 @@ Minor features
 :mod:`django.contrib.auth`
 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-* ...
+* The default iteration count for the PBKDF2 password hasher has been increased
+  by 20%. This backwards compatible change will not affect users who have
+  subclassed ``django.contrib.auth.hashers.PBKDF2PasswordHasher`` to change the
+  default value.
 
 :mod:`django.contrib.gis`
 ^^^^^^^^^^^^^^^^^^^^^^^^^^