File CVE-2023-49083.patch of Package python-cryptography.32695
From 66cb448876b1e95b637461d13560b970bae09e08 Mon Sep 17 00:00:00 2001
From: Alex Gaynor <alex.gaynor@gmail.com>
Date: Wed, 22 Nov 2023 16:49:56 -0500
Subject: [PATCH] Fixed crash when loading a PKCS#7 bundle with no certificates
---
src/cryptography/hazmat/backends/openssl/backend.py | 5 ++++-
tests/hazmat/primitives/test_pkcs7.py | 6 ++++++
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/src/cryptography/hazmat/backends/openssl/backend.py b/src/cryptography/hazmat/backends/openssl/backend.py
index 7c08862b307..adfd7aefe5f 100644
--- a/src/cryptography/hazmat/backends/openssl/backend.py
+++ b/src/cryptography/hazmat/backends/openssl/backend.py
@@ -1111,9 +1111,12 @@ def _load_pkcs7_certificates(self, p7) -> list[x509.Certificate]:
_Reasons.UNSUPPORTED_SERIALIZATION,
)
+ certs: list[x509.Certificate] = []
+ if p7.d.sign == self._ffi.NULL:
+ return certs
+
sk_x509 = p7.d.sign.cert
num = self._lib.sk_X509_num(sk_x509)
- certs = []
for i in range(num):
x509 = self._lib.sk_X509_value(sk_x509, i)
self.openssl_assert(x509 != self._ffi.NULL)
diff --git a/tests/hazmat/primitives/test_pkcs7.py b/tests/hazmat/primitives/test_pkcs7.py
index ceb84e5fb48..434a361057f 100644
--- a/tests/hazmat/primitives/test_pkcs7.py
+++ b/tests/hazmat/primitives/test_pkcs7.py
@@ -89,6 +89,12 @@ def test_load_pkcs7_unsupported_type(self, backend):
mode="rb",
)
+ def test_load_pkcs7_empty_certificates(self):
+ der = b"\x30\x0B\x06\x09\x2A\x86\x48\x86\xF7\x0D\x01\x07\x02"
+
+ certificates = pkcs7.load_der_pkcs7_certificates(der)
+ assert certificates == []
+
# We have no public verification API and won't be adding one until we get
# some requirements from users so this function exists to give us basic