/*

Copyright (c) 2020, Paul-Louis Ageneau
Copyright (c) 2018, Alexandre Janniaux
Copyright (c) 2020, Steven Siloti
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

  * Redistributions of source code must retain the above copyright
    notice, this list of conditions and the following disclaimer.
  * 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.
  * Neither the name of the author nor the names of its
    contributors may be used to endorse or promote products derived
    from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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.

*/

#ifndef TORRENT_SSL_HPP_INCLUDED
#define TORRENT_SSL_HPP_INCLUDED

#include "libtorrent/config.hpp"
#include "libtorrent/string_view.hpp"
#include "libtorrent/aux_/export.hpp"

#if TORRENT_USE_SSL

#include "libtorrent/aux_/disable_warnings_push.hpp"

#include <boost/asio.hpp>
#include <boost/asio/buffer.hpp>
#include <boost/system/error_code.hpp>

#ifndef BOOST_NO_EXCEPTIONS
#include <boost/system/system_error.hpp>
#endif

#ifdef TORRENT_USE_OPENSSL
#include <openssl/opensslv.h> // for OPENSSL_VERSION_NUMBER
#if OPENSSL_VERSION_NUMBER < 0x1000000fL
#error OpenSSL too old, use a recent version with SNI support
#endif
#ifdef TORRENT_WINDOWS
// because openssl includes winsock.h, we must include winsock2.h first
#include <winsock2.h>
#endif
#include <openssl/ssl.h>
#include <openssl/crypto.h>
#include <openssl/rand.h>
#include <boost/asio/ssl.hpp>
#endif

#ifdef TORRENT_USE_GNUTLS
#include <gnutls/gnutls.h>
#include <boost/asio/gnutls.hpp>
#endif

#include "libtorrent/aux_/disable_warnings_pop.hpp"

#ifdef TORRENT_BUILD_SIMULATOR
#include "simulator/simulator.hpp"
#endif

#include <string>
#include <cstddef>
#include <functional>
#include <exception>

namespace libtorrent {
namespace ssl {

using error_code = boost::system::error_code;

#if defined TORRENT_USE_OPENSSL
#if defined TORRENT_BUILD_SIMULATOR
	using sim::asio::ssl::context;
	using sim::asio::ssl::stream_base;
	using sim::asio::ssl::stream;
#else
	using boost::asio::ssl::context;
	using boost::asio::ssl::stream_base;
	using boost::asio::ssl::stream;
#endif
using boost::asio::ssl::verify_context;
#if BOOST_VERSION >= 107300
using boost::asio::ssl::host_name_verification;
#else
using host_name_verification = boost::asio::ssl::rfc2818_verification;
#endif

using native_context_type = SSL_CTX*;
using native_stream_type = SSL*;
using context_handle_type = native_context_type;
using stream_handle_type = native_stream_type;

typedef int (*server_name_callback_type)(SSL* s, int*, void* arg);

#elif defined TORRENT_USE_GNUTLS
using boost::asio::gnutls::context;
using boost::asio::gnutls::stream_base;
using boost::asio::gnutls::stream;
using boost::asio::gnutls::verify_context;
using boost::asio::gnutls::host_name_verification;

using native_context_type = context::native_handle_type;
using native_stream_type = stream_base::native_handle_type;
using context_handle_type = context*;
using stream_handle_type = stream_base*;

typedef bool (*server_name_callback_type)(stream_handle_type handle, std::string const& name, void* arg);

#endif

namespace error {

#if defined TORRENT_USE_OPENSSL
using boost::asio::error::get_ssl_category;
using boost::asio::ssl::error::get_stream_category;
#elif defined TORRENT_USE_GNUTLS
using boost::asio::gnutls::error::get_ssl_category;
using boost::asio::gnutls::error::get_stream_category;
#endif

}

inline context_handle_type get_handle(context &c)
{
#if defined TORRENT_USE_OPENSSL
	return c.native_handle();
#elif defined TORRENT_USE_GNUTLS
	return &c;
#endif
}

template<typename T>
stream_handle_type get_handle(stream<T>& s)
{
#if defined TORRENT_USE_OPENSSL
	return s.native_handle();
#elif defined TORRENT_USE_GNUTLS
	return &s;
#endif
}

template<typename T>
context_handle_type get_context_handle(stream<T>& s)
{
#if defined TORRENT_USE_OPENSSL
	return SSL_get_SSL_CTX(s.native_handle());
#elif defined TORRENT_USE_GNUTLS
	return &s.get_context();
#endif
}

TORRENT_EXTRA_EXPORT void set_trust_certificate(native_context_type nc, string_view pem, error_code &ec);

TORRENT_EXTRA_EXPORT void set_server_name_callback(context_handle_type c, server_name_callback_type cb, void* arg, error_code& ec);
TORRENT_EXTRA_EXPORT void set_host_name(stream_handle_type s, std::string const& name, error_code& ec);

TORRENT_EXTRA_EXPORT void set_context(stream_handle_type s, context_handle_type c);
TORRENT_EXTRA_EXPORT bool has_context(stream_handle_type s, context_handle_type c);
TORRENT_EXTRA_EXPORT context_handle_type get_context(stream_handle_type s);

} // ssl
} // libtorrent

#endif // TORRENT_USE_SSL

#endif
