credstash.py 文件源码

def _seal_aes_ctr(plaintext, key, nonce, digest_method):
    data_key, hmac_key = _halve_key(key)
    encryptor = Cipher(
        algorithms.AES(data_key),
        modes.CTR(nonce),
        backend=default_backend()
    ).encryptor()

    ciphertext = encryptor.update(plaintext.encode("utf-8")) + encryptor.finalize()
    return ciphertext, _get_hmac(hmac_key, ciphertext, digest_method)