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

#include "ae-common.h"
#include "cipher.h"
#include "lilliput-ae.h"



static void _generate_tag(
    const uint8_t key[KEY_BYTES],
    size_t        M_len,
    const uint8_t M[M_len],
    const uint8_t N[NONCE_BYTES],
    const uint8_t Auth[BLOCK_BYTES],
    uint8_t       tag[TAG_BYTES]
)
{
}

static void _encrypt_message(
    const uint8_t key[KEY_BYTES],
    size_t        M_len,
    const uint8_t M[M_len],
    const uint8_t N[NONCE_BYTES],
    const uint8_t tag[TAG_BYTES],
    uint8_t       C[M_len]
)
{
}

static void _decrypt_message(
    const uint8_t key[KEY_BYTES],
    size_t C_len,
    const uint8_t C[C_len],
    const uint8_t N[NONCE_BYTES],
    const uint8_t tag[TAG_BYTES],
    uint8_t       M[C_len]
)
{
}


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],
    uint8_t       ciphertext[message_len],
    uint8_t       tag[TAG_BYTES]
)
{
    uint8_t auth[BLOCK_BYTES];
    process_associated_data(key, auth_data_len, auth_data, auth);

    _generate_tag(key, message_len, message, nonce, auth, tag);

    _encrypt_message(key, message_len, message, nonce, tag, ciphertext);
}

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],
    uint8_t       message[ciphertext_len]
)
{
    _decrypt_message(key, ciphertext_len, ciphertext, nonce, tag, message);

    uint8_t auth[BLOCK_BYTES];
    process_associated_data(key, auth_data_len, auth_data, auth);

    uint8_t effective_tag[TAG_BYTES];
    _generate_tag(key, ciphertext_len, message, nonce, auth, effective_tag);

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