/*
 * Copyright (C) 2024 - 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.
 */

#ifndef LC_ASCON_LIGHTWEIGHT_H
#define LC_ASCON_LIGHTWEIGHT_H

#include "lc_export.h"
#include "lc_ascon_aead.h"
#include "lc_ascon_hash.h"

#ifdef __cplusplus
extern "C" {
#endif

/// \cond DO_NOT_DOCUMENT
/*
 * Alignment:
 * - hash alignment to adjust lc_ascon_cryptor
 * - hash for SHA-3 alignment
 */
#define LC_AL_STATE_SIZE                                                       \
	(LC_ASCON_HASH_STATE_SIZE + LC_ASCON_ALIGNMENT +                       \
	 LC_HASH_COMMON_ALIGNMENT)
#define LC_AL_CTX_SIZE                                                         \
	(sizeof(struct lc_aead_ctx) + sizeof(struct lc_ascon_cryptor) +        \
	 LC_AL_STATE_SIZE)
/// \endcond

/* Ascon-based AEAD-algorithm */
extern LC_DLL_IMPORT const struct lc_aead *lc_ascon_aead;

/**
 * @brief Allocate Ascon Lightweight cryptor context on heap
 *
 * @param [out] ctx Allocated Ascon lightweight cryptor context
 *
 * @return 0 on success, < 0 on error
 */
int lc_al_alloc(struct lc_aead_ctx **ctx);

/**
 * @brief Allocate stack memory for the Ascon lightweight cryptor context
 *
 * @param [in] name Name of the stack variable
 */
#define LC_AL_CTX_ON_STACK(name)                                               \
	_Pragma("GCC diagnostic push") _Pragma(                                \
		"GCC diagnostic ignored \"-Wdeclaration-after-statement\"")    \
		_Pragma("GCC diagnostic ignored \"-Wcast-align\"")             \
			LC_ALIGNED_BUFFER(name##_ctx_buf, LC_AL_CTX_SIZE,      \
					  LC_ASCON_ALIGNMENT);                 \
	struct lc_aead_ctx *name = (struct lc_aead_ctx *)name##_ctx_buf;       \
	LC_ASCON_SET_CTX(name, lc_ascon_128a, lc_ascon_aead);                  \
	struct lc_ascon_cryptor *__name_ascon_crypto = name->aead_state;       \
	__name_ascon_crypto->statesize = LC_ASCON_HASH_STATE_SIZE;             \
	__name_ascon_crypto->taglen = 16;                                      \
	_Pragma("GCC diagnostic pop")
/* invocation of lc_ak_zero_free(name); not needed */

#ifdef __cplusplus
}
#endif

#endif /* LC_ASCON_LIGHTWEIGHT_H */