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.
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| 1 | #!/usr/bin/env python3 | ||
| 2 | # SPDX-License-Identifier: GPL-2.0-or-later | ||
| 3 | # | ||
| 4 | # Script that generates known-good data used in the AEAD tests. | ||
| 5 | # | ||
| 6 | # Requires that python-cryptography be installed. | ||
| 7 | # | ||
| 8 | # Copyright 2026 Google LLC | ||
| 9 | |||
| 10 | import hashlib | ||
| 11 | import sys | ||
| 12 | import cryptography.hazmat.primitives.ciphers.aead | ||
| 13 | |||
| 14 | |||
| 15 | # Deterministically generate 'length' random bytes. | ||
| 16 | def rand_bytes(length): | ||
| 17 | seed = length | ||
| 18 | out = [] | ||
| 19 | for _ in range(length): | ||
| 20 | seed = (seed * 25214903917 + 11) % 2**48 | ||
| 21 | out.append((seed >> 16) % 256) | ||
| 22 | return bytes(out) | ||
| 23 | |||
| 24 | |||
| 25 | # Deterministically generate many different AEAD inputs using exactly the same | ||
| 26 | # method that the test uses; encrypt them using an independent implementation of | ||
| 27 | # the algorithm; compute the checksum of all the resulting (ciphertext, authtag) | ||
| 28 | # pairs concatenated to each other; and print the checksum as a C struct. | ||
| 29 | def gen_monte_carlo_checksum(alg): | ||
| 30 | blake2s = hashlib.blake2s() | ||
| 31 | for data_len in range(1025): | ||
| 32 | ad_len = data_len % 293 | ||
| 33 | pt = rand_bytes(data_len) | ||
| 34 | ad = rand_bytes(ad_len) | ||
| 35 | if alg == "aes-ccm": | ||
| 36 | key_len = [16, 24, 32][data_len % 3] | ||
| 37 | key = rand_bytes(key_len) | ||
| 38 | nonce = rand_bytes([7, 8, 9, 10, 11, 12, 13][data_len % 7]) | ||
| 39 | tag_len = [4, 6, 8, 10, 12, 14, 16][data_len % 7] | ||
| 40 | ccm = cryptography.hazmat.primitives.ciphers.aead.AESCCM( | ||
| 41 | key, tag_length=tag_len | ||
| 42 | ) | ||
| 43 | ct_and_tag = ccm.encrypt(nonce, pt, ad) | ||
| 44 | |||
| 45 | blake2s.update(ct_and_tag) | ||
| 46 | |||
| 47 | name = f"{alg.replace('-', '_')}_monte_carlo_checksum" | ||
| 48 | value = blake2s.digest() | ||
| 49 | print(f"static const u8 {name}[BLAKE2S_HASH_SIZE] = {{") | ||
| 50 | for i in range(0, len(value), 11): | ||
| 51 | line = "\t" + "".join(f"0x{b:02x}, " for b in value[i : i + 11]) | ||
| 52 | print(f"{line.rstrip()}") | ||
| 53 | print("};") | ||
| 54 | |||
| 55 | |||
| 56 | if len(sys.argv) != 2 or sys.argv[1] not in ("aes-ccm"): | ||
| 57 | sys.stderr.write("Usage: gen-aead-testvecs.py [aes-ccm]\n") | ||
| 58 | sys.exit(1) | ||
| 59 | |||
| 60 | gen_monte_carlo_checksum(sys.argv[1]) | ||