From 8378c1ff784a9601966b88f1c5587d50120038c3 Mon Sep 17 00:00:00 2001 From: Alex Gaynor Date: Mon, 27 Nov 2023 14:35:35 -0500 Subject: 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 f8776b732..45a644cf6 100644 --- a/src/cryptography/hazmat/backends/openssl/backend.py +++ b/src/cryptography/hazmat/backends/openssl/backend.py @@ -2454,9 +2454,12 @@ 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 138bc0f3b..559e1f274 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 -- 2.30.2