Add a KUnit test suite for the AES-CCM library API. It consists of: - All the shared test cases from aead-test-template.h. These include extensive consistency tests, a "Monte-Carlo test", and a benchmark. - Tests against hardcoded AES-CCM test vectors from external sources. - Tests for CCM-specific message length validation. To generate the expected aes_ccm_monte_carlo_checksum[] value, add a script gen-aead-testvecs.py which computes it using python-cryptography. Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Link: https://patch.msgid.link/20260802233005.161467-5-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@kernel.org>