| From 9fbf84efc861668755ab645530ec7be9cf3c6696 Mon Sep 17 00:00:00 2001 |
| From: Alex Gaynor <alex.gaynor@gmail.com> |
| Date: Tue, 7 Feb 2023 11:34:18 -0500 |
| Subject: [PATCH] Don't allow update_into to mutate immutable objects (#8230) |
| |
| CVE: CVE-2023-23931 |
| |
| Upstream-Status: Backport [https://github.com/pyca/cryptography/commit/9fbf84efc861668755ab645530ec7be9cf3c6696] |
| |
| Signed-off-by: Narpat Mali <narpat.mali@windriver.com> |
| --- |
| 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 286583f93..075d68fb9 100644 |
| --- a/src/cryptography/hazmat/backends/openssl/ciphers.py |
| +++ b/src/cryptography/hazmat/backends/openssl/ciphers.py |
| @@ -156,7 +156,7 @@ class _CipherContext: |
| 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 02127dd9c..bf3b047de 100644 |
| --- a/tests/hazmat/primitives/test_ciphers.py |
| +++ b/tests/hazmat/primitives/test_ciphers.py |
| @@ -318,6 +318,14 @@ class TestCipherUpdateInto: |
| 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) |
| -- |
| 2.40.0 |