45 lines
1.3 KiB
Diff
45 lines
1.3 KiB
Diff
|
From d2655d370586cb830e49acfb450f87598da60be8 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Simo Sorce <simo@redhat.com>
|
||
|
|
Date: Thu, 7 Dec 2023 12:49:07 -0500
|
||
|
|
Subject: [PATCH] Fix potential DoS issue with p2c header
|
||
|
|
|
||
|
|
Unbounded p2c headers may be used to cause an application that accept
|
||
|
|
PBES algorithms to spend alot of resources running PBKDF2 with a very
|
||
|
|
high number of iterations.
|
||
|
|
|
||
|
|
Clamp the default maximum to 16384 (double the default of 8192).
|
||
|
|
An application that wants to use more iterations will have to chenge the
|
||
|
|
jwa default max.
|
||
|
|
|
||
|
|
Fixes CVE-2023-6681
|
||
|
|
|
||
|
|
Signed-off-by: Simo Sorce <simo@redhat.com>
|
||
|
|
---
|
||
|
|
jwcrypto/jwa.py | 5 +++++
|
||
|
|
jwcrypto/tests.py | 12 ++++++++++++
|
||
|
|
2 files changed, 17 insertions(+)
|
||
|
|
|
||
|
|
diff --git a/jwcrypto/jwa.py b/jwcrypto/jwa.py
|
||
|
|
index de7a79f..ca4568e 100644
|
||
|
|
--- a/jwcrypto/jwa.py
|
||
|
|
+++ b/jwcrypto/jwa.py
|
||
|
|
@@ -29,6 +29,8 @@
|
||
|
|
|
||
|
|
# Implements RFC 7518 - JSON Web Algorithms (JWA)
|
||
|
|
|
||
|
|
+default_max_pbkdf2_iterations = 16384
|
||
|
|
+
|
||
|
|
|
||
|
|
@six.add_metaclass(abc.ABCMeta)
|
||
|
|
class JWAAlgorithm(object):
|
||
|
|
@@ -588,6 +590,9 @@ def __init__(self):
|
||
|
|
self.aeskwmap = {128: _A128KW, 192: _A192KW, 256: _A256KW}
|
||
|
|
|
||
|
|
def _get_key(self, alg, key, p2s, p2c):
|
||
|
|
+ if p2c > default_max_pbkdf2_iterations:
|
||
|
|
+ raise ValueError('Invalid p2c value, too large')
|
||
|
|
+
|
||
|
|
if isinstance(key, bytes):
|
||
|
|
plain = key
|
||
|
|
else:
|