/*

 * Copyright (C) 2000-2012 Free Software Foundation, Inc.

 * Copyright (C) 2017 Red Hat, 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_HANDSHAKE_H

#define GNUTLS_LIB_HANDSHAKE_H

#include "errors.h"

#include "record.h"

#include <assert.h>

/* The following two macros are used in the handshake state machines; the first

 * (IMED_RET) accounts for non-fatal errors and re-entry to current state, while

 * the latter invalidates the handshake on any error (to be used by functions

 * that are not expected to return non-fatal errors).

 */

#define IMED_RET( str, ret, allow_alert) do { \

	if (ret < 0) { \

		/* EAGAIN and INTERRUPTED are always non-fatal */ \

		if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED) \

			return ret; \

		if (ret == GNUTLS_E_GOT_APPLICATION_DATA && session->internals.initial_negotiation_completed != 0) \

			return ret; \

		if (session->internals.handshake_suspicious_loops < 16) { \

			if (ret == GNUTLS_E_LARGE_PACKET) { \

				session->internals.handshake_suspicious_loops++; \

				return ret; \

			} \

			/* a warning alert might interrupt handshake */ \

			if (allow_alert != 0 && ret==GNUTLS_E_WARNING_ALERT_RECEIVED) { \

				session->internals.handshake_suspicious_loops++; \

				return ret; \

			} \

		} \

		gnutls_assert(); \

		/* do not allow non-fatal errors at this point */ \

		if (gnutls_error_is_fatal(ret) == 0) ret = gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR); \

		session_invalidate(session); \

		_gnutls_handshake_hash_buffers_clear(session); \

		return ret; \

	} } while (0)

#define IMED_RET_FATAL( str, ret, allow_alert) do { \

	if (ret < 0) { \

		gnutls_assert(); \

		if (gnutls_error_is_fatal(ret) == 0) \

			ret = gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR); \

		session_invalidate(session); \

		_gnutls_handshake_hash_buffers_clear(session); \

		return ret; \

	} } while (0)

int _gnutls_send_handshake(gnutls_session_t session, mbuffer_st * bufel,

			   gnutls_handshake_description_t type);

int _gnutls_recv_handshake(gnutls_session_t session,

			   gnutls_handshake_description_t type,

			   unsigned int optional, gnutls_buffer_st * buf);

int

_gnutls_send_handshake2(gnutls_session_t session, mbuffer_st * bufel,

		        gnutls_handshake_description_t type, unsigned queue_only);

int _gnutls_generate_session_id(uint8_t * session_id, uint8_t * len);

int _gnutls_gen_server_random(gnutls_session_t session, int version);

void _gnutls_set_client_random(gnutls_session_t session, uint8_t * rnd);

ssize_t _gnutls_send_change_cipher_spec(gnutls_session_t session, int again);

int _gnutls_send_server_hello(gnutls_session_t session, int again);

int _gnutls_find_pk_algos_in_ciphersuites(uint8_t * data, int datalen);

int _gnutls_server_select_suite(gnutls_session_t session, uint8_t * data,

				unsigned int datalen, unsigned int scsv_only);

int _gnutls_negotiate_version(gnutls_session_t session,

			      uint8_t major, uint8_t minor,

			      unsigned allow_tls13);

int _gnutls_user_hello_func(gnutls_session_t session,

			    uint8_t major, uint8_t minor);

void _gnutls_handshake_hash_buffers_clear(gnutls_session_t session);

int _gnutls13_handshake_hash_buffers_synth(gnutls_session_t session,

					   const mac_entry_st *prf,

					   unsigned client);

#define STATE session->internals.handshake_state

#define FINAL_STATE session->internals.handshake_final_state

/* This returns true if we have got there

 * before (and not finished due to an interrupt).

 */

#define AGAIN(target) (STATE==target?1:0)

#define FAGAIN(target) (FINAL_STATE==target?1:0)

#define AGAIN2(state, target) (state==target?1:0)

/* return the remaining time in ms */

inline static int handshake_remaining_time(gnutls_session_t session)

{

	struct timespec *end = &session->internals.handshake_abs_timeout;

	if (end->tv_sec || end->tv_nsec) {

		struct timespec now;

		gnutls_gettime(&now;;

		if (now.tv_sec < end->tv_sec ||

		   (now.tv_sec == end->tv_sec && now.tv_nsec < end->tv_nsec))

		{

			long long now_ms = now.tv_sec * 1000LL + now.tv_nsec / 1000000;

			long long end_ms = end->tv_sec * 1000LL + end->tv_nsec / 1000000;

			return end_ms - now_ms;

		} else

			return gnutls_assert_val(GNUTLS_E_TIMEDOUT);

	}

	return 0;

}

/* Returns non-zero if the present credentials are sufficient for TLS1.3 negotiation.

 * This is to be used in client side only. On server side, it is allowed to start

 * without credentials.

 */

inline static unsigned have_creds_for_tls13(gnutls_session_t session)

{

	assert(session->security_parameters.entity == GNUTLS_CLIENT);

	if (_gnutls_get_cred(session, GNUTLS_CRD_CERTIFICATE) != NULL ||

	    _gnutls_get_cred(session, GNUTLS_CRD_PSK) != NULL)

		return 1;

	return 0;

}

int _gnutls_handshake_get_session_hash(gnutls_session_t session, gnutls_datum_t *shash);

int _gnutls_check_id_for_change(gnutls_session_t session);

int _gnutls_check_if_cert_hash_is_same(gnutls_session_t session, gnutls_certificate_credentials_t cred);

#include "handshake-defs.h"

int _gnutls_call_hook_func(gnutls_session_t session,

			   gnutls_handshake_description_t type,

			   int post, unsigned incoming,

			   const uint8_t *data, unsigned data_size);

int _gnutls_run_verify_callback(gnutls_session_t session, unsigned int side);

int _gnutls_recv_finished(gnutls_session_t session);

int _gnutls_send_finished(gnutls_session_t session, int again);

int _gnutls13_handshake_client(gnutls_session_t session);

int _gnutls13_handshake_server(gnutls_session_t session);

int

_gnutls13_recv_hello_retry_request(gnutls_session_t session,

				   gnutls_buffer_st *buf);

int

_gnutls13_recv_async_handshake(gnutls_session_t session);

#endif /* GNUTLS_LIB_HANDSHAKE_H */