Fix CVE-2023-23931

Don't allow update_into to mutate immutable objects

Resolves: RHEL-4932

0006-CVE-2023-23931.patch

@@ -0,0 +1,42 @@
+From 94a50a9731f35405f0357fa5f3b177d46a726ab3 Mon Sep 17 00:00:00 2001
+From: Alex Gaynor <alex.gaynor@gmail.com>
+Date: Tue, 31 Jan 2023 08:33:54 -0500
+Subject: [PATCH] Don't allow update_into to mutate immutable objects
+
+---
+ src/cryptography/hazmat/backends/openssl/ciphers.py | 2 +-
+ tests/hazmat/primitives/test_ciphers.py             | 8 ++++++++
+ 2 files changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/src/cryptography/hazmat/backends/openssl/ciphers.py b/src/cryptography/hazmat/backends/openssl/ciphers.py
+index 286583f9325..075d68fb905 100644
+--- a/src/cryptography/hazmat/backends/openssl/ciphers.py
++++ b/src/cryptography/hazmat/backends/openssl/ciphers.py
+@@ -156,7 +156,7 @@ def update_into(self, data: bytes, buf: bytes) -> int:
+         data_processed = 0
+         total_out = 0
+         outlen = self._backend._ffi.new("int *")
+-        baseoutbuf = self._backend._ffi.from_buffer(buf)
++        baseoutbuf = self._backend._ffi.from_buffer(buf, require_writable=True)
+         baseinbuf = self._backend._ffi.from_buffer(data)
+ 
+         while data_processed != total_data_len:
+diff --git a/tests/hazmat/primitives/test_ciphers.py b/tests/hazmat/primitives/test_ciphers.py
+index 02127dd9cab..bf3b047dec2 100644
+--- a/tests/hazmat/primitives/test_ciphers.py
++++ b/tests/hazmat/primitives/test_ciphers.py
+@@ -318,6 +318,14 @@ def test_update_into_buffer_too_small(self, backend):
+         with pytest.raises(ValueError):
+             encryptor.update_into(b"testing", buf)
+ 
++    def test_update_into_immutable(self, backend):
++        key = b"\x00" * 16
++        c = ciphers.Cipher(AES(key), modes.ECB(), backend)
++        encryptor = c.encryptor()
++        buf = b"\x00" * 32
++        with pytest.raises((TypeError, BufferError)):
++            encryptor.update_into(b"testing", buf)
++
+     @pytest.mark.supported(
+         only_if=lambda backend: backend.cipher_supported(
+             AES(b"\x00" * 16), modes.GCM(b"\x00" * 12)

python-cryptography.spec

@@ -11,7 +11,7 @@
 
 Name:           python-%{srcname}
 Version:        3.3.1
-Release:        2%{?dist}
+Release:        3%{?dist}
 Summary:        PyCA's cryptography library
 
 License:        ASL 2.0 or BSD
@@ -29,6 +29,10 @@ Source2:        gpgkey-05FD_9FA1_6CF7_5735_0D91_A560_235A_E5F1_29F9_ED98.gpg
 # See: https://projects.engineering.redhat.com/browse/RCM-72605
 ExcludeArch: i686
 
+# Security fix for CVE-2023-23931
+# Resolved upstream: https://github.com/pyca/cryptography/pull/8230
+Patch0006:      0006-CVE-2023-23931.patch
+
 BuildRequires:  openssl-devel
 BuildRequires:  gcc
 BuildRequires:  gnupg2
@@ -168,6 +172,10 @@ PYTHONPATH=%{buildroot}%{python3_sitearch} %{__python3} -m pytest -k "not (test_
 
 
 %changelog
+* Tue Aug 15 2023 Christian Heimes <cheimes@redhat.com> - 3.3.1-3
+- Fix CVE-2023-23931: Don't allow update_into to mutate immutable objects,
+- Resolves RHEL-4932
+
 * Mon Jan 18 2021 Tomas Orsava <torsava@redhat.com> - 3.3.1-2
 - Convert from Fedora to the python39 module in RHEL8
 - Resolves: rhbz#1877430