File CVE-2024-39329.patch of Package python-Django.34811

From 14fc40a7f990bae2d874c78d300c8af2d2c94809 Mon Sep 17 00:00:00 2001
From: Michael Manfre <mike@manfre.net>
Date: Fri, 14 Jun 2024 22:12:58 -0400
Subject: [PATCH] [4.2.x] Fixed CVE-2024-39329 -- Standarized timing of
 verify_password() when checking unusuable passwords.

Refs #20760.

Thanks Michael Manfre for the fix and to Adam Johnson for the review.
---
 django/contrib/auth/hashers.py   | 16 ++++++--
 tests/auth_tests/test_hashers.py | 68 ++++++++++++++++++++++++++++++++
 2 files changed, 81 insertions(+), 3 deletions(-)

diff --git a/django/contrib/auth/hashers.py b/django/contrib/auth/hashers.py
index c14ece20fb..59eceb4504 100644
--- a/django/contrib/auth/hashers.py
+++ b/django/contrib/auth/hashers.py
@@ -39,11 +39,21 @@ def check_password(password, encoded, setter=None, preferred='default'):
     If setter is specified, it'll be called when you need to
     regenerate the password.
     """
-    if password is None or not is_password_usable(encoded):
-        return False
+    fake_runtime = password is None or not is_password_usable(encoded)
 
     preferred = get_hasher(preferred)
-    hasher = identify_hasher(encoded)
+    try:
+        hasher = identify_hasher(encoded)
+    except ValueError:
+        # encoded is gibberish or uses a hasher that's no longer installed.
+        fake_runtime = True
+
+    if fake_runtime:
+        # Run the default password hasher once to reduce the timing difference
+        # between an existing user with an unusable password and a nonexistent
+        # user or missing hasher (similar to #20760).
+        make_password(get_random_string(UNUSABLE_PASSWORD_SUFFIX_LENGTH))
+        return False
 
     hasher_changed = hasher.algorithm != preferred.algorithm
     must_update = hasher_changed or preferred.must_update(encoded)
diff --git a/tests/auth_tests/test_hashers.py b/tests/auth_tests/test_hashers.py
index cf12fd4168..432d383c20 100644
--- a/tests/auth_tests/test_hashers.py
+++ b/tests/auth_tests/test_hashers.py
@@ -429,6 +429,74 @@ class TestUtilsHashPass(SimpleTestCase):
             check_password('wrong_password', encoded)
             self.assertEqual(hasher.harden_runtime.call_count, 1)
 
+    def test_check_password_calls_make_password_to_fake_runtime(self):
+        hasher = get_hasher("default")
+        cases = [
+            (None, None, None),  # no plain text password provided
+            ("foo", make_password(password=None), None),  # unusable encoded
+            ("letmein", make_password(password="letmein"), ValueError),  # valid encoded
+        ]
+        for password, encoded, hasher_side_effect in cases:
+            with (
+                self.subTest(encoded=encoded),
+                mock.patch(
+                    "django.contrib.auth.hashers.identify_hasher",
+                    side_effect=hasher_side_effect,
+                ) as mock_identify_hasher,
+                mock.patch(
+                    "django.contrib.auth.hashers.make_password"
+                ) as mock_make_password,
+                mock.patch(
+                    "django.contrib.auth.hashers.get_random_string",
+                    side_effect=lambda size: "x" * size,
+                ),
+                mock.patch.object(hasher, "verify"),
+            ):
+                # Ensure make_password is called to standardize timing.
+                check_password(password, encoded)
+                self.assertEqual(hasher.verify.call_count, 0)
+                self.assertEqual(mock_identify_hasher.mock_calls, [mock.call(encoded)])
+                self.assertEqual(
+                    mock_make_password.mock_calls,
+                    [mock.call("x" * UNUSABLE_PASSWORD_SUFFIX_LENGTH)],
+                )
+
+    def test_encode_invalid_salt(self):
+        hasher_classes = [
+            MD5PasswordHasher,
+            PBKDF2PasswordHasher,
+            PBKDF2SHA1PasswordHasher,
+            ScryptPasswordHasher,
+        ]
+        msg = "salt must be provided and cannot contain $."
+        for hasher_class in hasher_classes:
+            hasher = hasher_class()
+            for salt in [None, "", "sea$salt"]:
+                with self.subTest(hasher_class.__name__, salt=salt):
+                    with self.assertRaisesMessage(ValueError, msg):
+                        hasher.encode("password", salt)
+
+    def test_encode_password_required(self):
+        hasher_classes = [
+            MD5PasswordHasher,
+            PBKDF2PasswordHasher,
+            PBKDF2SHA1PasswordHasher,
+            ScryptPasswordHasher,
+        ]
+        msg = "password must be provided."
+        for hasher_class in hasher_classes:
+            hasher = hasher_class()
+            with self.subTest(hasher_class.__name__):
+                with self.assertRaisesMessage(TypeError, msg):
+                    hasher.encode(None, "seasalt")
+
+
+class BasePasswordHasherTests(SimpleTestCase):
+    not_implemented_msg = "subclasses of BasePasswordHasher must provide %s() method"
+
+    def setUp(self):
+        self.hasher = BasePasswordHasher()
+
     def test_load_library_no_algorithm(self):
         msg = "Hasher 'BasePasswordHasher' doesn't specify a library attribute"
         with self.assertRaisesMessage(ValueError, msg):
-- 
2.45.2