c++boostboost-beastbeast-websockets

Boost-beast websocket handshake problems


I am attempting to set up a websocket connection with a remote server and get the following error: The WebSocket handshake was declined by the remote peer

I am following this example: https://www.boost.org/doc/libs/1_70_0/libs/beast/example/websocket/client/sync/websocket_client_sync.cpp

For the following server: https://api.hitbtc.com/#socket-api-reference

Thanks for your help in advance!

int main(int argc, char** argv) {
    try
    {
        auto const host = "api.hitbtc.com";
        auto const port = "443";

        net::io_context ioc;
        tcp::resolver resolver{ ioc };
        websocket::stream<tcp::socket> ws{ ioc };

        auto const results = resolver.resolve(host, port);

        net::connect(ws.next_layer(), results.begin(), results.end());

        // Perform the websocket handshake - this is where i presume the issue is.
        ws.handshake(host, "/api/2/ws");

        beast::flat_buffer buffer;
        ws.read(buffer);
        ws.close(websocket::close_code::normal);
        std::cout << beast::make_printable(buffer.data()) << std::endl;
    }
    catch (std::exception const& e)
    {
        std::cerr << "Error: " << e.what() << std::endl;
        return EXIT_FAILURE;
    }
    return EXIT_SUCCESS;
}

Solution

  • You have to provide ssl context. Here is example from boost.org,

    and here is example for api.hitbtc handshake and getting Currency info via JSON-RPC (I've omitted certificate loading):

    #include <boost/beast/core.hpp>
    #include <boost/beast/ssl.hpp>
    #include <boost/beast/websocket.hpp>
    #include <boost/beast/websocket/ssl.hpp>
    #include <boost/asio/connect.hpp>
    #include <boost/asio/ip/tcp.hpp>
    #include <boost/asio/ssl/stream.hpp>
    #include <cstdlib>
    #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>
    
    // Sends a WebSocket message and prints the response
    int main(int argc, char** argv)
    {
        try
        {
            // Check command line arguments.
            auto const host = "api.hitbtc.com";
            auto const port = "443";
            auto const rpcJson = R"({"method":"getCurrency", "params":{"currency":"ETH"},"id":0})";
    
            // 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);
    
            // These objects perform our I/O
            tcp::resolver resolver{ioc};
            websocket::stream<beast::ssl_stream<tcp::socket>> ws{ioc, ctx};
    
            // Look up the domain name
            auto const results = resolver.resolve(host, port);
    
            // Make the connection on the IP address we get from a lookup
            net::connect(ws.next_layer().next_layer(), results.begin(), results.end());
    
            // Perform the SSL handshake
            ws.next_layer().handshake(ssl::stream_base::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-coro");
                }));
    
            // Perform the websocket handshake
            ws.handshake(host, "/api/2/ws");
    
            // Our message in this case should be stringified JSON-RPC request
            ws.write(net::buffer(std::string(rpcJson)));
    
            // This buffer will hold the incoming message
            beast::flat_buffer buffer;
    
            // Read a message into our buffer
            ws.read(buffer);
    
            // Close the WebSocket connection
            ws.close(websocket::close_code::normal);
    
            // 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;
        }
        catch(std::exception const& e)
        {
            std::cerr << "Error: " << e.what() << std::endl;
            return EXIT_FAILURE;
        }
        return EXIT_SUCCESS;
    }
    

    You should get stringified JSON-RPC response. In this case for getCurrency("ETH") request, the response would be:

    {"jsonrpc":"2.0","result":{"id":"ETH","fullName":"Ethereum","crypto":true,"payinEnabled":true,"payinPaymentId":false,"payinConfirmations":2,"payoutEnabled":true,"payoutIsPaymentId":false,"transferEnabled":true,"delisted":false,"payoutFee":"0.0428"},"id":null}