Commit 67325669 authored by Alex Gaynor's avatar Alex Gaynor
Browse files

Bump the default iterations for PBKDF2. 

The rate at which we've increased this has not been keeping up with hardware (and software) improvements, and we're now considerably behind where we should be. The delta between our performance and an optimized implementation's performance prevents us from improving that further, but hopefully once Python 2.7.8 and 3.4+ get into more hands we can more aggressively increase this number.
parent ebb13bbd

django/contrib/auth/hashers.py

+2 −2
Original line number Diff line number Diff line
@@ -222,12 +222,12 @@ class PBKDF2PasswordHasher(BasePasswordHasher): 
    """

    Secure password hashing using the PBKDF2 algorithm (recommended)



    Configured to use PBKDF2 + HMAC + SHA256 with 12000 iterations.

    Configured to use PBKDF2 + HMAC + SHA256 with 20000 iterations.

    The result is a 64 byte binary string.  Iterations may be changed

    safely but you must rename the algorithm if you change SHA256.

    """

    algorithm = "pbkdf2_sha256"

    iterations = 12000

    iterations = 20000

    digest = hashlib.sha256



    def encode(self, password, salt, iterations=None):

django/contrib/auth/tests/test_hashers.py

+3 −3
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ class TestUtilsHashPass(SimpleTestCase): 
    def test_pkbdf2(self):

        encoded = make_password('lètmein', 'seasalt', 'pbkdf2_sha256')

        self.assertEqual(encoded,

            'pbkdf2_sha256$12000$seasalt$Ybw8zsFxqja97tY/o6G+Fy1ksY4U/Hw3DRrGED6Up4s=')

            'pbkdf2_sha256$20000$seasalt$oBSd886ysm3AqYun62DOdin8YcfbU1z9cksZSuLP9r0=')

        self.assertTrue(is_password_usable(encoded))

        self.assertTrue(check_password('lètmein', encoded))

        self.assertFalse(check_password('lètmeinz', encoded))
@@ -211,14 +211,14 @@ class TestUtilsHashPass(SimpleTestCase): 
        hasher = PBKDF2PasswordHasher()

        encoded = hasher.encode('lètmein', 'seasalt2')

        self.assertEqual(encoded,

            'pbkdf2_sha256$12000$seasalt2$hlDLKsxgkgb1aeOppkM5atCYw5rPzAjCNQZ4NYyUROw=')

            'pbkdf2_sha256$20000$seasalt2$Flpve/uAcyo6+IFI6YAhjeABGPVbRQjzHDxRhqxewgw=')

        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$12000$seasalt2$JeMRVfjjgtWw3/HzlnlfqBnQ6CA=')

            'pbkdf2_sha1$20000$seasalt2$pJt86NmjAweBY1StBvxCu7l1o9o=')

        self.assertTrue(hasher.verify('lètmein', encoded))



    def test_upgrade(self):

django/utils/crypto.py

+8 −6
Original line number Diff line number Diff line
@@ -145,12 +145,14 @@ else: 


        HMAC+SHA256 is used as the default pseudo random function.



        As of 2011, 10,000 iterations was the recommended default which

        took 100ms on a 2.2Ghz Core 2 Duo. This is probably the bare

        minimum for security given 1000 iterations was recommended in

        2001. This code is very well optimized for CPython and is only

        four times slower than openssl's implementation. Look in

        django.contrib.auth.hashers for the present default.

        As of 2014, 100,000 iterations was the recommended default which took

        100ms on a 2.7Ghz Intel i7 with an optimized implementation. This is

        probably the bare minimum for security given 1000 iterations was

        recommended in 2001. This code is very well optimized for CPython and

        is about five times slower than OpenSSL's implementation. Look in

        django.contrib.auth.hashers for the present default, it is lower than

        the recommended 100,000 because of the performance difference between

        this and an optimized implementation.

        """

        assert iterations > 0

        if not digest:

docs/internals/howto-release-django.txt

+1 −1
Original line number Diff line number Diff line
@@ -91,7 +91,7 @@ any time leading up to the actual release: 


#. If this is a major release, make sure the tests pass, then increase

   the default PBKDF2 iterations in

   ``django.contrib.auth.hashers.PBKDF2PasswordHasher`` by about 10%

   ``django.contrib.auth.hashers.PBKDF2PasswordHasher`` by about 20%

   (pick a round number). Run the tests, and update the 3 failing

   hasher tests with the new values. Make sure this gets noted in the

   release notes (see release notes on 1.6 for an example).