cryptography NULL pointer deference with pkcs12.serialize_key_and_certificates when called with a non-matching certificate and private key and an hmac_hash override

Vulnerability Description

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Starting in version 38.0.0 and prior to version 42.0.4, if `pkcs12.serialize_key_and_certificates` is called with both a certificate whose public key did not match the provided private key and an `encryption_algorithm` with `hmac_hash` set (via `PrivateFormat.PKCS12.encryption_builder().hmac_hash(...)`, then a NULL pointer dereference would occur, crashing the Python process. This has been resolved in version 42.0.4, the first version in which a `ValueError` is properly raised.

References

• https://github.com/pyca/cryptography/security/advisories/GHSA-6vqw-3v5j-54x4
• https://github.com/pyca/cryptography/pull/10423
• https://github.com/pyca/cryptography/commit/97d231672763cdb5959a3b191e692a362f1b9e55