#include "libs/beast/example/common/root_certificates.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 <cstdlib>

#include <functional>

#include <iostream>

#include <memory>

#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_;

    std::string text_;

 

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,

            char const* text)

    {

        // Save these for later

        host_ = host;

        text_ = text;

 

        // 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");

 

        // 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());

        // 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");

        }

 

        // 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");

            }));

 

        // Perform the websocket handshake

        ws_.async_handshake(host_, "/", beast::bind_front_handler(&session::on_handshake,shared_from_this()));

    }

 

    void on_handshake(beast::error_code ec)

    {

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

        // Send the message

        ws_.async_write(net::buffer(text_),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

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

    }

 

    void on_read(beast::error_code ec,std::size_t bytes_transferred)

    {

        boost::ignore_unused(bytes_transferred);

 

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

 

        // Close the WebSocket connection

        ws_.async_close(websocket::close_code::normal,beast::bind_front_handler(&session::on_close,shared_from_this()));

    }

 

    void on_close(beast::error_code ec)

    {

        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 = argv[1];

    auto const port = argv[2];

    auto const text = argv[3];

 

    // 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

    load_root_certificates(ctx);

 

    // Launch the asynchronous operation

    std::make_shared<session>(ioc, ctx)->run(host, port, text);

 

    // Run the I/O service. The call will return when

    // the socket is closed.

    ioc.run();

 

    return EXIT_SUCCESS;

}