1 //
2 // Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot com)
3 //
4 // Distributed under the Boost Software License, Version 1.0. (See accompanying
5 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
6 //
7 // Official repository: https://github.com/boostorg/beast
8 //
9
10 //------------------------------------------------------------------------------
11 //
12 // Example: WebSocket SSL client, coroutine
13 //
14 //------------------------------------------------------------------------------
15
16 #include "example/common/root_certificates.hpp"
17
18 #include <boost/beast/core.hpp>
19 #include <boost/beast/ssl.hpp>
20 #include <boost/beast/websocket.hpp>
21 #include <boost/beast/websocket/ssl.hpp>
22 #include <boost/asio/spawn.hpp>
23 #include <cstdlib>
24 #include <functional>
25 #include <iostream>
26 #include <string>
27
28 namespace beast = boost::beast; // from <boost/beast.hpp>
29 namespace http = beast::http; // from <boost/beast/http.hpp>
30 namespace websocket = beast::websocket; // from <boost/beast/websocket.hpp>
31 namespace net = boost::asio; // from <boost/asio.hpp>
32 namespace ssl = boost::asio::ssl; // from <boost/asio/ssl.hpp>
33 using tcp = boost::asio::ip::tcp; // from <boost/asio/ip/tcp.hpp>
34
35 //------------------------------------------------------------------------------
36
37 // Report a failure
38 void
fail(beast::error_code ec,char const * what)39 fail(beast::error_code ec, char const* what)
40 {
41 std::cerr << what << ": " << ec.message() << "\n";
42 }
43
44 // Sends a WebSocket message and prints the response
45 void
do_session(std::string host,std::string const & port,std::string const & text,net::io_context & ioc,ssl::context & ctx,net::yield_context yield)46 do_session(
47 std::string host,
48 std::string const& port,
49 std::string const& text,
50 net::io_context& ioc,
51 ssl::context& ctx,
52 net::yield_context yield)
53 {
54 beast::error_code ec;
55
56 // These objects perform our I/O
57 tcp::resolver resolver(ioc);
58 websocket::stream<
59 beast::ssl_stream<beast::tcp_stream>> ws(ioc, ctx);
60
61 // Look up the domain name
62 auto const results = resolver.async_resolve(host, port, yield[ec]);
63 if(ec)
64 return fail(ec, "resolve");
65
66 // Set a timeout on the operation
67 beast::get_lowest_layer(ws).expires_after(std::chrono::seconds(30));
68
69 // Make the connection on the IP address we get from a lookup
70 auto ep = beast::get_lowest_layer(ws).async_connect(results, yield[ec]);
71 if(ec)
72 return fail(ec, "connect");
73
74 // Update the host_ string. This will provide the value of the
75 // Host HTTP header during the WebSocket handshake.
76 // See https://tools.ietf.org/html/rfc7230#section-5.4
77 host += ':' + std::to_string(ep.port());
78
79 // Set a timeout on the operation
80 beast::get_lowest_layer(ws).expires_after(std::chrono::seconds(30));
81
82 // Set a decorator to change the User-Agent of the handshake
83 ws.set_option(websocket::stream_base::decorator(
84 [](websocket::request_type& req)
85 {
86 req.set(http::field::user_agent,
87 std::string(BOOST_BEAST_VERSION_STRING) +
88 " websocket-client-coro");
89 }));
90
91 // Perform the SSL handshake
92 ws.next_layer().async_handshake(ssl::stream_base::client, yield[ec]);
93 if(ec)
94 return fail(ec, "ssl_handshake");
95
96 // Turn off the timeout on the tcp_stream, because
97 // the websocket stream has its own timeout system.
98 beast::get_lowest_layer(ws).expires_never();
99
100 // Set suggested timeout settings for the websocket
101 ws.set_option(
102 websocket::stream_base::timeout::suggested(
103 beast::role_type::client));
104
105 // Perform the websocket handshake
106 ws.async_handshake(host, "/", yield[ec]);
107 if(ec)
108 return fail(ec, "handshake");
109
110 // Send the message
111 ws.async_write(net::buffer(std::string(text)), yield[ec]);
112 if(ec)
113 return fail(ec, "write");
114
115 // This buffer will hold the incoming message
116 beast::flat_buffer buffer;
117
118 // Read a message into our buffer
119 ws.async_read(buffer, yield[ec]);
120 if(ec)
121 return fail(ec, "read");
122
123 // Close the WebSocket connection
124 ws.async_close(websocket::close_code::normal, yield[ec]);
125 if(ec)
126 return fail(ec, "close");
127
128 // If we get here then the connection is closed gracefully
129
130 // The make_printable() function helps print a ConstBufferSequence
131 std::cout << beast::make_printable(buffer.data()) << std::endl;
132 }
133
134 //------------------------------------------------------------------------------
135
main(int argc,char ** argv)136 int main(int argc, char** argv)
137 {
138 // Check command line arguments.
139 if(argc != 4)
140 {
141 std::cerr <<
142 "Usage: websocket-client-coro-ssl <host> <port> <text>\n" <<
143 "Example:\n" <<
144 " websocket-client-coro-ssl echo.websocket.org 443 \"Hello, world!\"\n";
145 return EXIT_FAILURE;
146 }
147 auto const host = argv[1];
148 auto const port = argv[2];
149 auto const text = argv[3];
150
151 // The io_context is required for all I/O
152 net::io_context ioc;
153
154 // The SSL context is required, and holds certificates
155 ssl::context ctx{ssl::context::tlsv12_client};
156
157 // This holds the root certificate used for verification
158 load_root_certificates(ctx);
159
160 // Launch the asynchronous operation
161 boost::asio::spawn(ioc, std::bind(
162 &do_session,
163 std::string(host),
164 std::string(port),
165 std::string(text),
166 std::ref(ioc),
167 std::ref(ctx),
168 std::placeholders::_1));
169
170 // Run the I/O service. The call will return when
171 // the socket is closed.
172 ioc.run();
173
174 return EXIT_SUCCESS;
175 }
176