!66 Fixed crash when loading a PKCS#7 bundle with no certificates

From: @li_ning_jie 
Reviewed-by: @dillon_chen 
Signed-off-by: @dillon_chen

backport-Fixed-crash-when-loading-a-PKCS-7-bundle-with-no-certificates.patch

@@ -0,0 +1,49 @@
+From 6d71ead8d1910857e8cd778bc34c46c06e870a69 Mon Sep 17 00:00:00 2001
+From: Alex Gaynor <alex.gaynor@gmail.com>
+Date: Wed, 29 Nov 2023 11:37:52 +0800
+Subject: [PATCH] Fixed crash when loading a PKCS#7 bundle with no certificates
+ (#9926)
+
+---
+ 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 a3fe1bc..58e7207 100644
+--- a/src/cryptography/hazmat/backends/openssl/backend.py
++++ b/src/cryptography/hazmat/backends/openssl/backend.py
+@@ -2383,9 +2383,12 @@ class Backend:
+                 _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 4e61c5e..d8170bf 100644
+--- a/tests/hazmat/primitives/test_pkcs7.py
++++ b/tests/hazmat/primitives/test_pkcs7.py
+@@ -89,6 +89,12 @@ class TestPKCS7Loading:
+                 mode="rb",
+             )
+ 
++    def test_load_pkcs7_empty_certificates(self, backend):
++        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
+-- 
+2.33.0
+

python-cryptography.spec

@@ -1,7 +1,7 @@
 %global pypi_name cryptography
 Name:           python-%{pypi_name}
 Version:        40.0.2
-Release:        2
+Release:        3
 Summary:        PyCA's cryptography library
 License:        ASL 2.0 or BSD
 URL:            https://cryptography.io/en/latest/  
@@ -10,6 +10,7 @@ Source1:        cargo-vendor-cache.tar.gz
 
 Patch6002:      backport-provide-openssl-apis-related-to-SM-for-python.patch
 Patch6003:      backport-CVE-2023-38325.patch
+Patch6004:      backport-Fixed-crash-when-loading-a-PKCS-7-bundle-with-no-certificates.patch
 
 BuildRequires:  openssl-devel cargo
 BuildRequires:  gcc
@@ -86,6 +87,9 @@ EOF
 %doc README.rst docs
 
 %changelog
+* Wed Nov 29 2023 liningjie <liningjie@xfusion.com> - 40.0.2-3
+- Fixed crash when loading a PKCS#7 bundle with no certificates
+
 * Tue Jul 25 2023 shixuantong <shixuantong1@huawei.com> - 40.0.2-2
 - fix CVE-2023-38325