/*
 * Copyright (C) 2022 - 2026, Stephan Mueller <smueller@chronox.de>
 *
 * License: see LICENSE file in root directory
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
 * WHICH ARE HEREBY 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 NOT ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */
/*
 * This code is derived in parts from the code distribution provided with
 * https://github.com/pq-crystals/kyber
 *
 * That code is released under Public Domain
 * (https://creativecommons.org/share-your-work/public-domain/cc0/).
 */

#include "kyber_type.h"
#include "kyber_internal.h"
#include "kyber_kdf.h"

#include "lc_memset_secure.h"
#include "ret_checkers.h"
#include "visibility.h"

int lc_kex_uake_initiator_init_internal(struct lc_kyber_pk *pk_e_i,
					struct lc_kyber_ct *ct_e_i,
					struct lc_kyber_ss *tk,
					struct lc_kyber_sk *sk_e,
					const struct lc_kyber_pk *pk_r,
					struct lc_rng_ctx *rng_ctx)
{
	int ret;

	CKINT(lc_kyber_keypair(pk_e_i, sk_e, rng_ctx));
	CKINT(lc_kyber_enc_internal(ct_e_i, tk, pk_r, rng_ctx));

out:
	return ret;
}

LC_INTERFACE_FUNCTION(int, lc_kex_uake_initiator_init,
		      struct lc_kyber_pk *pk_e_i, struct lc_kyber_ct *ct_e_i,
		      struct lc_kyber_ss *tk, struct lc_kyber_sk *sk_e,
		      const struct lc_kyber_pk *pk_r)
{
	return lc_kex_uake_initiator_init_internal(pk_e_i, ct_e_i, tk, sk_e,
						   pk_r, lc_seeded_rng);
}

int lc_kex_uake_responder_ss_internal(
	struct lc_kyber_ct *ct_e_r, uint8_t *shared_secret,
	size_t shared_secret_len, const uint8_t *kdf_nonce,
	size_t kdf_nonce_len, const struct lc_kyber_pk *pk_e_i,
	const struct lc_kyber_ct *ct_e_i, const struct lc_kyber_sk *sk_r,
	struct lc_rng_ctx *rng_ctx)
{
	struct lc_kyber_ss ss[2];
	int ret;

	CKINT(lc_kyber_enc_internal(ct_e_r, &ss[0], pk_e_i, rng_ctx));
	CKINT(lc_kyber_dec(&ss[1], ct_e_i, sk_r));
	CKINT(kyber_kdf3(ss[0].ss, LC_KYBER_SSBYTES, ss[1].ss, LC_KYBER_SSBYTES,
			 kdf_nonce, kdf_nonce_len, shared_secret,
			 shared_secret_len));

out:
	lc_memset_secure(ss, 0, sizeof(ss));
	return ret;
}

LC_INTERFACE_FUNCTION(int, lc_kex_uake_responder_ss, struct lc_kyber_ct *ct_e_r,
		      uint8_t *shared_secret, size_t shared_secret_len,
		      const uint8_t *kdf_nonce, size_t kdf_nonce_len,
		      const struct lc_kyber_pk *pk_e_i,
		      const struct lc_kyber_ct *ct_e_i,
		      const struct lc_kyber_sk *sk_r)
{
	return lc_kex_uake_responder_ss_internal(ct_e_r, shared_secret,
						 shared_secret_len, kdf_nonce,
						 kdf_nonce_len, pk_e_i, ct_e_i,
						 sk_r, lc_seeded_rng);
}

LC_INTERFACE_FUNCTION(int, lc_kex_uake_initiator_ss, uint8_t *shared_secret,
		      size_t shared_secret_len, const uint8_t *kdf_nonce,
		      size_t kdf_nonce_len, const struct lc_kyber_ct *ct_e_r,
		      const struct lc_kyber_ss *tk,
		      const struct lc_kyber_sk *sk_e)
{
	struct lc_kyber_ss ss;
	int ret;

	CKINT(lc_kyber_dec(&ss, ct_e_r, sk_e));
	CKINT(kyber_kdf3(ss.ss, LC_KYBER_SSBYTES, tk->ss, LC_KYBER_SSBYTES,
			 kdf_nonce, kdf_nonce_len, shared_secret,
			 shared_secret_len));

out:
	lc_memset_secure(&ss, 0, sizeof(ss));
	return ret;
}

int lc_kex_ake_initiator_init_internal(struct lc_kyber_pk *pk_e_i,
				       struct lc_kyber_ct *ct_e_i,
				       struct lc_kyber_ss *tk,
				       struct lc_kyber_sk *sk_e,
				       const struct lc_kyber_pk *pk_r,
				       struct lc_rng_ctx *rng_ctx)
{
	int ret;

	CKINT(lc_kyber_keypair(pk_e_i, sk_e, rng_ctx));
	CKINT(lc_kyber_enc_internal(ct_e_i, tk, pk_r, rng_ctx));

out:
	return ret;
}

LC_INTERFACE_FUNCTION(int, lc_kex_ake_initiator_init,
		      struct lc_kyber_pk *pk_e_i, struct lc_kyber_ct *ct_e_i,
		      struct lc_kyber_ss *tk, struct lc_kyber_sk *sk_e,
		      const struct lc_kyber_pk *pk_r)
{
	return lc_kex_ake_initiator_init_internal(pk_e_i, ct_e_i, tk, sk_e,
						  pk_r, lc_seeded_rng);
}

int lc_kex_ake_responder_ss_internal(
	struct lc_kyber_ct *ct_e_r_1, struct lc_kyber_ct *ct_e_r_2,
	uint8_t *shared_secret, size_t shared_secret_len,
	const uint8_t *kdf_nonce, size_t kdf_nonce_len,
	const struct lc_kyber_pk *pk_e_i, const struct lc_kyber_ct *ct_e_i,
	const struct lc_kyber_sk *sk_r, const struct lc_kyber_pk *pk_i,
	struct lc_rng_ctx *rng_ctx)
{
	struct lc_kyber_ss ss[3];
	int ret;

	CKINT(lc_kyber_enc_internal(ct_e_r_1, &ss[0], pk_e_i, rng_ctx));
	CKINT(lc_kyber_enc_internal(ct_e_r_2, &ss[1], pk_i, rng_ctx));
	CKINT(lc_kyber_dec(&ss[2], ct_e_i, sk_r));
	CKINT(kyber_kdf4(ss[0].ss, LC_KYBER_SSBYTES, ss[1].ss, LC_KYBER_SSBYTES,
			 ss[2].ss, LC_KYBER_SSBYTES, kdf_nonce, kdf_nonce_len,
			 shared_secret, shared_secret_len));

out:
	lc_memset_secure(ss, 0, sizeof(ss));
	return ret;
}

LC_INTERFACE_FUNCTION(int, lc_kex_ake_responder_ss,
		      struct lc_kyber_ct *ct_e_r_1,
		      struct lc_kyber_ct *ct_e_r_2, uint8_t *shared_secret,
		      size_t shared_secret_len, const uint8_t *kdf_nonce,
		      size_t kdf_nonce_len, const struct lc_kyber_pk *pk_e_i,
		      const struct lc_kyber_ct *ct_e_i,
		      const struct lc_kyber_sk *sk_r,
		      const struct lc_kyber_pk *pk_i)
{
	return lc_kex_ake_responder_ss_internal(
		ct_e_r_1, ct_e_r_2, shared_secret, shared_secret_len, kdf_nonce,
		kdf_nonce_len, pk_e_i, ct_e_i, sk_r, pk_i, lc_seeded_rng);
}

LC_INTERFACE_FUNCTION(int, lc_kex_ake_initiator_ss, uint8_t *shared_secret,
		      size_t shared_secret_len, const uint8_t *kdf_nonce,
		      size_t kdf_nonce_len, const struct lc_kyber_ct *ct_e_r_1,
		      const struct lc_kyber_ct *ct_e_r_2,
		      const struct lc_kyber_ss *tk,
		      const struct lc_kyber_sk *sk_e,
		      const struct lc_kyber_sk *sk_i)
{
	struct lc_kyber_ss ss[2];
	int ret;

	CKINT(lc_kyber_dec(&ss[0], ct_e_r_1, sk_e));
	CKINT(lc_kyber_dec(&ss[1], ct_e_r_2, sk_i));
	CKINT(kyber_kdf4(ss[0].ss, LC_KYBER_SSBYTES, ss[1].ss, LC_KYBER_SSBYTES,
			 tk->ss, LC_KYBER_SSBYTES, kdf_nonce, kdf_nonce_len,
			 shared_secret, shared_secret_len));

out:
	lc_memset_secure(ss, 0, sizeof(ss));
	return ret;
}
