/*

 * Copyright (c) 2023 Markus Friedl.  All rights reserved.

 * Copyright (c) 2025 Loganaden Velvindron. All rights reserved.

 * Copyright (c) 2025 Jaykishan Mutkawoa. All rights reserved.

 * Copyright (c) 2025 Keshwarsingh "Kavish" Nadan. All rights reserved.

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "includes.h"

#include <sys/types.h>

#include <stdio.h>

#ifdef HAVE_STDINT_H

#include <stdint.h>

#endif

#include <stdbool.h>

#include <string.h>

#include <signal.h>

#ifdef HAVE_ENDIAN_H

# include <endian.h>

#endif

#include "kex.h"

#if DROPBEAR_MLKEM768

#include "dbutil.h"

#include "compat.h"

#pragma GCC diagnostic push

#pragma GCC diagnostic ignored "-Wunused-parameter"

#include "libcrux_mlkem768_sha3.h"

#pragma GCC diagnostic pop

#include "mlkem768.h"

#include "dbrandom.h"

int

crypto_kem_mlkem768_keypair(unsigned char *pk, unsigned char *sk)

{

  unsigned char rnd[LIBCRUX_ML_KEM_KEY_PAIR_PRNG_LEN];

  struct libcrux_mlkem768_keypair keypair;

  static_assert(sizeof(keypair.sk.value) == crypto_kem_mlkem768_SECRETKEYBYTES, "len");

  static_assert(sizeof(keypair.pk.value) == crypto_kem_mlkem768_PUBLICKEYBYTES, "len");

  genrandom(rnd, sizeof(rnd));

  keypair = libcrux_ml_kem_mlkem768_portable_generate_key_pair(rnd);

  memcpy(pk, keypair.pk.value, crypto_kem_mlkem768_PUBLICKEYBYTES);

  memcpy(sk, keypair.sk.value, crypto_kem_mlkem768_SECRETKEYBYTES);

  m_burn(rnd, sizeof(rnd));

  m_burn(&keypair, sizeof(keypair));

  return 0;

}

int

crypto_kem_mlkem768_enc(unsigned char *c, unsigned char *k,

const unsigned char *pk)

{

  unsigned char rnd[LIBCRUX_ML_KEM_ENC_PRNG_LEN];

  struct libcrux_mlkem768_enc_result enc;

  struct libcrux_mlkem768_pk mlkem_pub;

  static_assert(sizeof(mlkem_pub.value) == crypto_kem_mlkem768_PUBLICKEYBYTES, "len");

  static_assert(sizeof(enc.fst.value) == crypto_kem_mlkem768_CIPHERTEXTBYTES, "len");

  static_assert(sizeof(enc.snd) == crypto_kem_mlkem768_BYTES, "len");

  memcpy(mlkem_pub.value, pk, crypto_kem_mlkem768_PUBLICKEYBYTES);

  /* generate and encrypt KEM key with client key */

  genrandom(rnd, sizeof(rnd));

  enc = libcrux_ml_kem_mlkem768_portable_encapsulate(&mlkem_pub, rnd);

  memcpy(c, enc.fst.value, sizeof(enc.fst.value));

  memcpy(k, enc.snd, sizeof(enc.snd));

  m_burn(rnd, sizeof(rnd));

  m_burn(&enc, sizeof(enc));

  return 0;

}

int

crypto_kem_mlkem768_dec(unsigned char *k, const unsigned char *c,

const unsigned char *sk)

{

  struct libcrux_mlkem768_sk mlkem_priv;

  struct libcrux_mlkem768_ciphertext mlkem_ciphertext;

  static_assert(sizeof(mlkem_priv.value) == crypto_kem_mlkem768_SECRETKEYBYTES, "len");

  static_assert(sizeof(mlkem_ciphertext.value) == crypto_kem_mlkem768_CIPHERTEXTBYTES, "len");

  memcpy(mlkem_priv.value, sk, crypto_kem_mlkem768_SECRETKEYBYTES);

  memcpy(mlkem_ciphertext.value, c, crypto_kem_mlkem768_CIPHERTEXTBYTES);

  libcrux_ml_kem_mlkem768_portable_decapsulate(&mlkem_priv,

      &mlkem_ciphertext, k);

  m_burn(&mlkem_priv, sizeof(mlkem_priv));

  m_burn(&mlkem_ciphertext, sizeof(mlkem_ciphertext));

  return 0;

}

#endif /* USE_MLKEM768 */