/*
 * Copyright (C) 2000-2012 Free Software Foundation, Inc.
 *
 * Author: Nikos Mavrogiannopoulos
 *
 * This file is part of GnuTLS.
 *
 * The GnuTLS is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>
 *
 */

#ifndef GNUTLS_LIB_HASH_INT_H
#define GNUTLS_LIB_HASH_INT_H

#include "gnutls_int.h"
#include <gnutls/crypto.h>
#include <crypto-backend.h>
#include <crypto.h>

/* for message digests */

extern int crypto_mac_prio;
extern gnutls_crypto_mac_st _gnutls_mac_ops;

extern int crypto_digest_prio;
extern gnutls_crypto_digest_st _gnutls_digest_ops;

typedef int (*hash_func) (void *handle, const void *text, size_t size);
typedef int (*nonce_func) (void *handle, const void *text, size_t size);
typedef int (*output_func) (void *src_ctx, void *digest,
			    size_t digestsize);
typedef void (*hash_deinit_func) (void *handle);

typedef struct {
	const mac_entry_st *e;
	hash_func hash;
	output_func output;
	hash_deinit_func deinit;

	const void *key;	/* esoteric use by SSL3 MAC functions */
	int keysize;

	void *handle;
} digest_hd_st;

typedef struct {
	const mac_entry_st *e;
	int mac_len;

	hash_func hash;
	nonce_func setnonce;
	output_func output;
	hash_deinit_func deinit;

	void *handle;
} mac_hd_st;

/* basic functions */
int _gnutls_digest_exists(gnutls_digest_algorithm_t algo);

int _gnutls_mac_exists(gnutls_mac_algorithm_t algorithm);
int _gnutls_mac_init(mac_hd_st *, const mac_entry_st * e,
		     const void *key, int keylen);

int _gnutls_mac_fast(gnutls_mac_algorithm_t algorithm, const void *key,
		     int keylen, const void *text, size_t textlen,
		     void *digest);

inline static int
_gnutls_mac(mac_hd_st * handle, const void *text, size_t textlen)
{
	if (textlen > 0) {
		return handle->hash(handle->handle, text, textlen);
	}
	return 0;
}

inline static void _gnutls_mac_output(mac_hd_st * handle, void *digest)
{
	if (digest != NULL) {
		handle->output(handle->handle, digest, handle->mac_len);
	}
}

inline static int
_gnutls_mac_set_nonce(mac_hd_st * handle, const void *nonce, size_t n_size)
{
	if (handle->setnonce)
		return handle->setnonce(handle->handle, nonce, n_size);
	return 0;
}

void _gnutls_mac_deinit(mac_hd_st * handle, void *digest);

/* Hash interface */
int _gnutls_hash_init(digest_hd_st *, const mac_entry_st * e);

inline static int
_gnutls_hash(digest_hd_st * handle, const void *text, size_t textlen)
{
	if (textlen > 0) {
		return handle->hash(handle->handle, text, textlen);
	}
	return 0;
}

/* when the current output is needed without calling deinit
 */
#define _gnutls_hash_output(h, d) \
  (h)->output((h)->handle, d, _gnutls_hash_get_algo_len((h)->e))

void _gnutls_hash_deinit(digest_hd_st * handle, void *digest);

int
_gnutls_hash_fast(gnutls_digest_algorithm_t algorithm,
		  const void *text, size_t textlen, void *digest);

#ifdef ENABLE_SSL3
/* helper functions */
int _gnutls_mac_init_ssl3(digest_hd_st *, const mac_entry_st * e,
			  void *key, int keylen);
int _gnutls_mac_deinit_ssl3(digest_hd_st * handle, void *digest);
int _gnutls_mac_output_ssl3(digest_hd_st * handle, void *digest);

int _gnutls_ssl3_generate_random(void *secret, int secret_len,
				 void *rnd, int random_len, int bytes,
				 uint8_t * ret);

int _gnutls_mac_deinit_ssl3_handshake(digest_hd_st * handle, void *digest,
				      uint8_t * key, uint32_t key_size);
#endif

inline static int IS_SHA(gnutls_digest_algorithm_t algo)
{
	if (algo == GNUTLS_DIG_SHA1 || algo == GNUTLS_DIG_SHA224 ||
	    algo == GNUTLS_DIG_SHA256 || algo == GNUTLS_DIG_SHA384 ||
	    algo == GNUTLS_DIG_SHA512)
		return 1;
	return 0;
}

#endif /* GNUTLS_LIB_HASH_INT_H */