main.cpp

//
// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Official repository: https://github.com/boostorg/beast
//

//------------------------------------------------------------------------------
//
// Example: WebSocket SSL client, asynchronous
//
//------------------------------------------------------------------------------

#include <boost/certify/https_verification.hpp>

#include <boost/beast/core.hpp>
#include <boost/beast/ssl.hpp>
#include <boost/beast/websocket.hpp>
#include <boost/beast/websocket/ssl.hpp>
#include <boost/asio/strand.hpp>
#include <iostream>
#include <string>

namespace beast = boost::beast;         // from <boost/beast.hpp>
namespace http = beast::http;           // from <boost/beast/http.hpp>
namespace websocket = beast::websocket; // from <boost/beast/websocket.hpp>
namespace net = boost::asio;            // from <boost/asio.hpp>
namespace ssl = boost::asio::ssl;       // from <boost/asio/ssl.hpp>
using tcp = boost::asio::ip::tcp;       // from <boost/asio/ip/tcp.hpp>

//------------------------------------------------------------------------------

// Report a failure
void
fail(beast::error_code ec, char const* what)
{
    std::cerr << what << ": " << ec.message() << "\n";
}

// Sends a WebSocket message and prints the response
class session : public std::enable_shared_from_this<session>
{
    tcp::resolver resolver_;
    websocket::stream<
            beast::ssl_stream<beast::tcp_stream>> ws_;
    beast::flat_buffer buffer_;
    std::string host_;

public:
    // Resolver and socket require an io_context
    explicit
    session(net::io_context& ioc, ssl::context& ctx)
            : resolver_(net::make_strand(ioc))
            , ws_(net::make_strand(ioc), ctx)
    {
    }

    // Start the asynchronous operation
    void
    run(
            char const* host,
            char const* port)
    {
        // Save these for later
        host_ = host;

        // Look up the domain name
        resolver_.async_resolve(
                host,
                port,
                beast::bind_front_handler(
                        &session::on_resolve,
                        shared_from_this()));
    }

    void
    on_resolve(
            beast::error_code ec,
            tcp::resolver::results_type results)
    {
        if(ec)
            return fail(ec, "resolve");

        // Set a timeout on the operation
        beast::get_lowest_layer(ws_).expires_after(std::chrono::seconds(30));

        // Make the connection on the IP address we get from a lookup
        beast::get_lowest_layer(ws_).async_connect(
                results,
                beast::bind_front_handler(
                        &session::on_connect,
                        shared_from_this()));
    }

    void
    on_connect(beast::error_code ec, tcp::resolver::results_type::endpoint_type ep)
    {
        if(ec)
            return fail(ec, "connect");

        // Set a timeout on the operation
        beast::get_lowest_layer(ws_).expires_after(std::chrono::seconds(30));

        // Set SNI Hostname (many hosts need this to handshake successfully)
        if(! SSL_set_tlsext_host_name(
                ws_.next_layer().native_handle(),
                host_.c_str()))
        {
            ec = beast::error_code(static_cast<int>(::ERR_get_error()),
                                   net::error::get_ssl_category());
            return fail(ec, "connect");
        }

        // Update the host_ string. This will provide the value of the
        // Host HTTP header during the WebSocket handshake.
        // See https://tools.ietf.org/html/rfc7230#section-5.4
        host_ += ':' + std::to_string(ep.port());

        // Perform the SSL handshake
        ws_.next_layer().async_handshake(
                ssl::stream_base::client,
                beast::bind_front_handler(
                        &session::on_ssl_handshake,
                        shared_from_this()));
    }

    void
    on_ssl_handshake(beast::error_code ec)
    {
        if(ec)
            return fail(ec, "ssl_handshake");

        // Turn off the timeout on the tcp_stream, because
        // the websocket stream has its own timeout system.
        beast::get_lowest_layer(ws_).expires_never();

        // Set suggested timeout settings for the websocket
        ws_.set_option(
                websocket::stream_base::timeout::suggested(
                        beast::role_type::client));

        // Set a decorator to change the User-Agent of the handshake
        ws_.set_option(websocket::stream_base::decorator(
                [](websocket::request_type& req)
                {
                    req.set(http::field::user_agent,
                            std::string(BOOST_BEAST_VERSION_STRING) +
                            " websocket-client-async-ssl C++ forever <3");
                }));

        // Perform the websocket handshake
        ws_.async_handshake(host_, "/events",
                            beast::bind_front_handler(
                                    &session::on_handshake,
                                    shared_from_this()));
    }

    void
    on_handshake(beast::error_code ec)
    {
        if(ec)
            return fail(ec, "handshake");
        ws_.async_read(
                buffer_,
                beast::bind_front_handler(
                        &session::on_read,
                        shared_from_this()));
        /*
        // Send the message
        ws_.async_write(
                net::buffer(""),
                beast::bind_front_handler(
                        &session::on_write,
                        shared_from_this()));*/
    }

    void
    on_write(
            beast::error_code ec,
            std::size_t bytes_transferred)
    {
        boost::ignore_unused(bytes_transferred);

        if(ec)
            return fail(ec, "write");
        // Read a message into our buffer

    }

    void
    on_read(
            beast::error_code ec,
            std::size_t bytes_transferred)
    {
        std::cout << bytes_transferred << " bytes recieved" << std::endl;
        //std::cout << beast::make_printable(buffer_.data()) << std::endl;

        if(ec)
            return fail(ec, "read");

        ws_.async_read(
                buffer_,
                beast::bind_front_handler(
                        &session::on_read,
                        shared_from_this()));
    }

    void
    on_close(beast::error_code ec)
    {
        std::cout << beast::make_printable(buffer_.data()) << std::endl;
        if(ec)
            return fail(ec, "close");

        // If we get here then the connection is closed gracefully

        // The make_printable() function helps print a ConstBufferSequence
        std::cout << beast::make_printable(buffer_.data()) << std::endl;
    }
};

//------------------------------------------------------------------------------

int main(int argc, char** argv)
{
    // Check command line arguments.
    /*
    if(argc != 4)
    {
        std::cerr <<
                  "Usage: websocket-client-async-ssl <host> <port> <text>\n" <<
                  "Example:\n" <<
                  "    websocket-client-async-ssl echo.websocket.org 443 \"Hello, world!\"\n";
        return EXIT_FAILURE;
    }*/
    auto const host = "ws.backpack.tf";
    auto const port = "443";

    // The io_context is required for all I/O
    net::io_context ioc;

    // The SSL context is required, and holds certificates
    ssl::context ctx{ssl::context::tlsv12_client};

    // This holds the root certificate used for verification
    try
    {
        // This holds the root certificate used for verification
        ctx.set_verify_mode(ssl::context::verify_peer |
                            ssl::context::verify_fail_if_no_peer_cert);
        ctx.set_default_verify_paths();
        boost::certify::enable_native_https_server_verification(ctx);
    }
    catch (std::exception const& e)
    {
        std::cerr << "Error: " << e.what() << std::endl;
        return EXIT_FAILURE;
    }

    // Launch the asynchronous operation
    std::make_shared<session>(ioc, ctx)->run(host, port);

    // Run the I/O service. The call will return when
    // the socket is closed.
    ioc.run();

    return EXIT_SUCCESS;
}