tjh.dev
1commit 08dbad8552ecca85d3e38072f94eb864b143d218
2Author: Niklas Hambüchen <mail@nh2.me>
3Date: Mon Jan 22 12:52:06 2024 +0000
4
5 Cherry-pick fix for CVE-2023-49083
6
7 Cherry-Picked-From: f09c261ca10a31fe41b1262306db7f8f1da0e48a
8 Cherry-Picked-By: Niklas Hambüchen <mail@nh2.me>
9
10diff --git a/src/cryptography/hazmat/backends/openssl/backend.py b/src/cryptography/hazmat/backends/openssl/backend.py
11index a3fe1bce4..58e7207c4 100644
12--- a/src/cryptography/hazmat/backends/openssl/backend.py
13+++ b/src/cryptography/hazmat/backends/openssl/backend.py
14@@ -2383,9 +2383,12 @@ class Backend:
15 _Reasons.UNSUPPORTED_SERIALIZATION,
16 )
17
18+ certs: list[x509.Certificate] = []
19+ if p7.d.sign == self._ffi.NULL:
20+ return certs
21+
22 sk_x509 = p7.d.sign.cert
23 num = self._lib.sk_X509_num(sk_x509)
24- certs = []
25 for i in range(num):
26 x509 = self._lib.sk_X509_value(sk_x509, i)
27 self.openssl_assert(x509 != self._ffi.NULL)
28diff --git a/tests/hazmat/primitives/test_pkcs7.py b/tests/hazmat/primitives/test_pkcs7.py
29index 4e61c5ef5..d8170bfb9 100644
30--- a/tests/hazmat/primitives/test_pkcs7.py
31+++ b/tests/hazmat/primitives/test_pkcs7.py
32@@ -89,6 +89,12 @@ class TestPKCS7Loading:
33 mode="rb",
34 )
35
36+ def test_load_pkcs7_empty_certificates(self, backend):
37+ der = b"\x30\x0B\x06\x09\x2A\x86\x48\x86\xF7\x0D\x01\x07\x02"
38+
39+ certificates = pkcs7.load_der_pkcs7_certificates(der)
40+ assert certificates == []
41+
42
43 # We have no public verification API and won't be adding one until we get
44 # some requirements from users so this function exists to give us basic