GHSA-W7PP-M8WF-VJ6R Cipher.update_into can corrupt memory if passed an immutable python object as the outbuf

Previously, Cipher.updateinto would accept Python objects which implement the buffer protocol, but provide only immutable buffers: pycon outbuf = b"\x00" 32 c = ciphers.CipherAESb"\x00" 32, modes.ECB.encryptor c.updateintob"\x00" 16, outbuf 16 outbuf...