88 lines
3.6 KiB
Diff
88 lines
3.6 KiB
Diff
From 156d3186c96e3ec2ca73b8b25dc2ef366e38df14 Mon Sep 17 00:00:00 2001
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From: Michael Manfre <mike@manfre.net>
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Date: Fri, 14 Jun 2024 22:12:58 -0400
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Subject: [PATCH] [4.2.x] Fixed CVE-2024-39329 -- Standarized timing of
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verify_password() when checking unusuable passwords.
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Refs #20760.
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Thanks Michael Manfre for the fix and to Adam Johnson for the review.
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---
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django/contrib/auth/hashers.py | 10 ++++++++--
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tests/auth_tests/test_hashers.py | 32 ++++++++++++++++++++++++++++++++
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2 files changed, 40 insertions(+), 2 deletions(-)
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diff --git a/django/contrib/auth/hashers.py b/django/contrib/auth/hashers.py
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index 9db5a12e13..f11bc8a0f3 100644
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--- a/django/contrib/auth/hashers.py
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+++ b/django/contrib/auth/hashers.py
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@@ -43,14 +43,20 @@ def check_password(password, encoded, setter=None, preferred="default"):
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If setter is specified, it'll be called when you need to
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regenerate the password.
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"""
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- if password is None or not is_password_usable(encoded):
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- return False
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+ fake_runtime = password is None or not is_password_usable(encoded)
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preferred = get_hasher(preferred)
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try:
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hasher = identify_hasher(encoded)
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except ValueError:
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# encoded is gibberish or uses a hasher that's no longer installed.
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+ fake_runtime = True
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+
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+ if fake_runtime:
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+ # Run the default password hasher once to reduce the timing difference
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+ # between an existing user with an unusable password and a nonexistent
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+ # user or missing hasher (similar to #20760).
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+ make_password(get_random_string(UNUSABLE_PASSWORD_SUFFIX_LENGTH))
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return False
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hasher_changed = hasher.algorithm != preferred.algorithm
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diff --git a/tests/auth_tests/test_hashers.py b/tests/auth_tests/test_hashers.py
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index 36f22d5f09..3da495f2be 100644
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--- a/tests/auth_tests/test_hashers.py
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+++ b/tests/auth_tests/test_hashers.py
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@@ -613,6 +613,38 @@ class TestUtilsHashPass(SimpleTestCase):
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check_password("wrong_password", encoded)
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self.assertEqual(hasher.harden_runtime.call_count, 1)
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+ def test_check_password_calls_make_password_to_fake_runtime(self):
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+ hasher = get_hasher("default")
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+ cases = [
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+ (None, None, None), # no plain text password provided
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+ ("foo", make_password(password=None), None), # unusable encoded
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+ ("letmein", make_password(password="letmein"), ValueError), # valid encoded
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+ ]
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+ for password, encoded, hasher_side_effect in cases:
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+ with (
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+ self.subTest(encoded=encoded),
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+ mock.patch(
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+ "django.contrib.auth.hashers.identify_hasher",
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+ side_effect=hasher_side_effect,
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+ ) as mock_identify_hasher,
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+ mock.patch(
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+ "django.contrib.auth.hashers.make_password"
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+ ) as mock_make_password,
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+ mock.patch(
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+ "django.contrib.auth.hashers.get_random_string",
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+ side_effect=lambda size: "x" * size,
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+ ),
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+ mock.patch.object(hasher, "verify"),
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+ ):
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+ # Ensure make_password is called to standardize timing.
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+ check_password(password, encoded)
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+ self.assertEqual(hasher.verify.call_count, 0)
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+ self.assertEqual(mock_identify_hasher.mock_calls, [mock.call(encoded)])
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+ self.assertEqual(
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+ mock_make_password.mock_calls,
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+ [mock.call("x" * UNUSABLE_PASSWORD_SUFFIX_LENGTH)],
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+ )
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+
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def test_encode_invalid_salt(self):
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hasher_classes = [
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MD5PasswordHasher,
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--
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2.45.2
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