#include <stdbool.h>
#include <stdint.h>
#include <string.h>

#include "lilliput-ae.h"


static void _process_associated_data(
    const uint8_t key[KEY_BYTES],
    size_t auth_data_len, const uint8_t auth_data[auth_data_len],
    uint8_t auth[BLOCK_BYTES]
)
{
}

static void _encrypt_message(
    const uint8_t key[KEY_BYTES],
    size_t message_len, const uint8_t message[message_len],
    const uint8_t nonce[NONCE_BYTES],

    size_t *ciphertext_len, uint8_t ciphertext[message_len+BLOCK_BYTES],
    uint8_t final[BLOCK_BYTES]
)
{
}

static void _decrypt_message(
    const uint8_t key[KEY_BYTES],
    size_t ciphertext_len, const uint8_t ciphertext[ciphertext_len],
    const uint8_t nonce[NONCE_BYTES],

    size_t *message_len, uint8_t message[ciphertext_len],
    uint8_t final[BLOCK_BYTES]
)
{
}

static void _generate_tag(
    const uint8_t final[BLOCK_BYTES],
    const uint8_t auth[BLOCK_BYTES],
    uint8_t tag[TAG_BYTES]
)
{
}


void lilliput_ae_encrypt(
    size_t message_len,    const uint8_t message[message_len],
    size_t  auth_data_len, const uint8_t auth_data[auth_data_len],
    const uint8_t key[KEY_BYTES],
    const uint8_t nonce[NONCE_BYTES],

    size_t *ciphertext_len, uint8_t ciphertext[message_len+BLOCK_BYTES],
    uint8_t tag[TAG_BYTES]
)
{
    uint8_t auth[BLOCK_BYTES];
    _process_associated_data(key, auth_data_len, auth_data, auth);

    uint8_t final[BLOCK_BYTES];
    _encrypt_message(key, message_len, message, nonce,
                     ciphertext_len, ciphertext, final);

    _generate_tag(final, auth, tag);
}

bool lilliput_ae_decrypt(
    size_t ciphertext_len, const uint8_t ciphertext[ciphertext_len],
    size_t auth_data_len,  const uint8_t auth_data[auth_data_len],
    const uint8_t key[KEY_BYTES],
    const uint8_t nonce[NONCE_BYTES],
    const uint8_t tag[TAG_BYTES],

    size_t *message_len, uint8_t message[ciphertext_len]
)
{
    uint8_t auth[BLOCK_BYTES];
    _process_associated_data(key, auth_data_len, auth_data, auth);

    uint8_t final[BLOCK_BYTES];
    _decrypt_message(key, ciphertext_len, ciphertext, nonce,
                     message_len, message, final);

    uint8_t effective_tag[TAG_BYTES];
    _generate_tag(final, auth, effective_tag);

    return memcmp(tag, effective_tag, TAG_BYTES) == 0;
}