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: HTTP SSL server, synchronous
13 //
14 //------------------------------------------------------------------------------
15
16 #include "example/common/server_certificate.hpp"
17
18 #include <boost/beast/core.hpp>
19 #include <boost/beast/http.hpp>
20 #include <boost/beast/ssl.hpp>
21 #include <boost/beast/version.hpp>
22 #include <boost/asio/ip/tcp.hpp>
23 #include <boost/asio/ssl/stream.hpp>
24 #include <boost/config.hpp>
25 #include <cstdlib>
26 #include <iostream>
27 #include <memory>
28 #include <string>
29 #include <thread>
30
31 namespace beast = boost::beast; // from <boost/beast.hpp>
32 namespace http = beast::http; // from <boost/beast/http.hpp>
33 namespace net = boost::asio; // from <boost/asio.hpp>
34 namespace ssl = boost::asio::ssl; // from <boost/asio/ssl.hpp>
35 using tcp = boost::asio::ip::tcp; // from <boost/asio/ip/tcp.hpp>
36
37 // Return a reasonable mime type based on the extension of a file.
38 beast::string_view
mime_type(beast::string_view path)39 mime_type(beast::string_view path)
40 {
41 using beast::iequals;
42 auto const ext = [&path]
43 {
44 auto const pos = path.rfind(".");
45 if(pos == beast::string_view::npos)
46 return beast::string_view{};
47 return path.substr(pos);
48 }();
49 if(iequals(ext, ".htm")) return "text/html";
50 if(iequals(ext, ".html")) return "text/html";
51 if(iequals(ext, ".php")) return "text/html";
52 if(iequals(ext, ".css")) return "text/css";
53 if(iequals(ext, ".txt")) return "text/plain";
54 if(iequals(ext, ".js")) return "application/javascript";
55 if(iequals(ext, ".json")) return "application/json";
56 if(iequals(ext, ".xml")) return "application/xml";
57 if(iequals(ext, ".swf")) return "application/x-shockwave-flash";
58 if(iequals(ext, ".flv")) return "video/x-flv";
59 if(iequals(ext, ".png")) return "image/png";
60 if(iequals(ext, ".jpe")) return "image/jpeg";
61 if(iequals(ext, ".jpeg")) return "image/jpeg";
62 if(iequals(ext, ".jpg")) return "image/jpeg";
63 if(iequals(ext, ".gif")) return "image/gif";
64 if(iequals(ext, ".bmp")) return "image/bmp";
65 if(iequals(ext, ".ico")) return "image/vnd.microsoft.icon";
66 if(iequals(ext, ".tiff")) return "image/tiff";
67 if(iequals(ext, ".tif")) return "image/tiff";
68 if(iequals(ext, ".svg")) return "image/svg+xml";
69 if(iequals(ext, ".svgz")) return "image/svg+xml";
70 return "application/text";
71 }
72
73 // Append an HTTP rel-path to a local filesystem path.
74 // The returned path is normalized for the platform.
75 std::string
path_cat(beast::string_view base,beast::string_view path)76 path_cat(
77 beast::string_view base,
78 beast::string_view path)
79 {
80 if(base.empty())
81 return std::string(path);
82 std::string result(base);
83 #ifdef BOOST_MSVC
84 char constexpr path_separator = '\\';
85 if(result.back() == path_separator)
86 result.resize(result.size() - 1);
87 result.append(path.data(), path.size());
88 for(auto& c : result)
89 if(c == '/')
90 c = path_separator;
91 #else
92 char constexpr path_separator = '/';
93 if(result.back() == path_separator)
94 result.resize(result.size() - 1);
95 result.append(path.data(), path.size());
96 #endif
97 return result;
98 }
99
100 // This function produces an HTTP response for the given
101 // request. The type of the response object depends on the
102 // contents of the request, so the interface requires the
103 // caller to pass a generic lambda for receiving the response.
104 template<
105 class Body, class Allocator,
106 class Send>
107 void
handle_request(beast::string_view doc_root,http::request<Body,http::basic_fields<Allocator>> && req,Send && send)108 handle_request(
109 beast::string_view doc_root,
110 http::request<Body, http::basic_fields<Allocator>>&& req,
111 Send&& send)
112 {
113 // Returns a bad request response
114 auto const bad_request =
115 [&req](beast::string_view why)
116 {
117 http::response<http::string_body> res{http::status::bad_request, req.version()};
118 res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
119 res.set(http::field::content_type, "text/html");
120 res.keep_alive(req.keep_alive());
121 res.body() = std::string(why);
122 res.prepare_payload();
123 return res;
124 };
125
126 // Returns a not found response
127 auto const not_found =
128 [&req](beast::string_view target)
129 {
130 http::response<http::string_body> res{http::status::not_found, req.version()};
131 res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
132 res.set(http::field::content_type, "text/html");
133 res.keep_alive(req.keep_alive());
134 res.body() = "The resource '" + std::string(target) + "' was not found.";
135 res.prepare_payload();
136 return res;
137 };
138
139 // Returns a server error response
140 auto const server_error =
141 [&req](beast::string_view what)
142 {
143 http::response<http::string_body> res{http::status::internal_server_error, req.version()};
144 res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
145 res.set(http::field::content_type, "text/html");
146 res.keep_alive(req.keep_alive());
147 res.body() = "An error occurred: '" + std::string(what) + "'";
148 res.prepare_payload();
149 return res;
150 };
151
152 // Make sure we can handle the method
153 if( req.method() != http::verb::get &&
154 req.method() != http::verb::head)
155 return send(bad_request("Unknown HTTP-method"));
156
157 // Request path must be absolute and not contain "..".
158 if( req.target().empty() ||
159 req.target()[0] != '/' ||
160 req.target().find("..") != beast::string_view::npos)
161 return send(bad_request("Illegal request-target"));
162
163 // Build the path to the requested file
164 std::string path = path_cat(doc_root, req.target());
165 if(req.target().back() == '/')
166 path.append("index.html");
167
168 // Attempt to open the file
169 beast::error_code ec;
170 http::file_body::value_type body;
171 body.open(path.c_str(), beast::file_mode::scan, ec);
172
173 // Handle the case where the file doesn't exist
174 if(ec == beast::errc::no_such_file_or_directory)
175 return send(not_found(req.target()));
176
177 // Handle an unknown error
178 if(ec)
179 return send(server_error(ec.message()));
180
181 // Cache the size since we need it after the move
182 auto const size = body.size();
183
184 // Respond to HEAD request
185 if(req.method() == http::verb::head)
186 {
187 http::response<http::empty_body> res{http::status::ok, req.version()};
188 res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
189 res.set(http::field::content_type, mime_type(path));
190 res.content_length(size);
191 res.keep_alive(req.keep_alive());
192 return send(std::move(res));
193 }
194
195 // Respond to GET request
196 http::response<http::file_body> res{
197 std::piecewise_construct,
198 std::make_tuple(std::move(body)),
199 std::make_tuple(http::status::ok, req.version())};
200 res.set(http::field::server, BOOST_BEAST_VERSION_STRING);
201 res.set(http::field::content_type, mime_type(path));
202 res.content_length(size);
203 res.keep_alive(req.keep_alive());
204 return send(std::move(res));
205 }
206
207 //------------------------------------------------------------------------------
208
209 // Report a failure
210 void
fail(beast::error_code ec,char const * what)211 fail(beast::error_code ec, char const* what)
212 {
213 std::cerr << what << ": " << ec.message() << "\n";
214 }
215
216 // This is the C++11 equivalent of a generic lambda.
217 // The function object is used to send an HTTP message.
218 template<class Stream>
219 struct send_lambda
220 {
221 Stream& stream_;
222 bool& close_;
223 beast::error_code& ec_;
224
225 explicit
send_lambdasend_lambda226 send_lambda(
227 Stream& stream,
228 bool& close,
229 beast::error_code& ec)
230 : stream_(stream)
231 , close_(close)
232 , ec_(ec)
233 {
234 }
235
236 template<bool isRequest, class Body, class Fields>
237 void
operator ()send_lambda238 operator()(http::message<isRequest, Body, Fields>&& msg) const
239 {
240 // Determine if we should close the connection after
241 close_ = msg.need_eof();
242
243 // We need the serializer here because the serializer requires
244 // a non-const file_body, and the message oriented version of
245 // http::write only works with const messages.
246 http::serializer<isRequest, Body, Fields> sr{msg};
247 http::write(stream_, sr, ec_);
248 }
249 };
250
251 // Handles an HTTP server connection
252 void
do_session(tcp::socket & socket,ssl::context & ctx,std::shared_ptr<std::string const> const & doc_root)253 do_session(
254 tcp::socket& socket,
255 ssl::context& ctx,
256 std::shared_ptr<std::string const> const& doc_root)
257 {
258 bool close = false;
259 beast::error_code ec;
260
261 // Construct the stream around the socket
262 beast::ssl_stream<tcp::socket&> stream{socket, ctx};
263
264 // Perform the SSL handshake
265 stream.handshake(ssl::stream_base::server, ec);
266 if(ec)
267 return fail(ec, "handshake");
268
269 // This buffer is required to persist across reads
270 beast::flat_buffer buffer;
271
272 // This lambda is used to send messages
273 send_lambda<beast::ssl_stream<tcp::socket&>> lambda{stream, close, ec};
274
275 for(;;)
276 {
277 // Read a request
278 http::request<http::string_body> req;
279 http::read(stream, buffer, req, ec);
280 if(ec == http::error::end_of_stream)
281 break;
282 if(ec)
283 return fail(ec, "read");
284
285 // Send the response
286 handle_request(*doc_root, std::move(req), lambda);
287 if(ec)
288 return fail(ec, "write");
289 if(close)
290 {
291 // This means we should close the connection, usually because
292 // the response indicated the "Connection: close" semantic.
293 break;
294 }
295 }
296
297 // Perform the SSL shutdown
298 stream.shutdown(ec);
299 if(ec)
300 return fail(ec, "shutdown");
301
302 // At this point the connection is closed gracefully
303 }
304
305 //------------------------------------------------------------------------------
306
main(int argc,char * argv[])307 int main(int argc, char* argv[])
308 {
309 try
310 {
311 // Check command line arguments.
312 if (argc != 4)
313 {
314 std::cerr <<
315 "Usage: http-server-sync-ssl <address> <port> <doc_root>\n" <<
316 "Example:\n" <<
317 " http-server-sync-ssl 0.0.0.0 8080 .\n";
318 return EXIT_FAILURE;
319 }
320 auto const address = net::ip::make_address(argv[1]);
321 auto const port = static_cast<unsigned short>(std::atoi(argv[2]));
322 auto const doc_root = std::make_shared<std::string>(argv[3]);
323
324 // The io_context is required for all I/O
325 net::io_context ioc{1};
326
327 // The SSL context is required, and holds certificates
328 ssl::context ctx{ssl::context::tlsv12};
329
330 // This holds the self-signed certificate used by the server
331 load_server_certificate(ctx);
332
333 // The acceptor receives incoming connections
334 tcp::acceptor acceptor{ioc, {address, port}};
335 for(;;)
336 {
337 // This will receive the new connection
338 tcp::socket socket{ioc};
339
340 // Block until we get a connection
341 acceptor.accept(socket);
342
343 // Launch the session, transferring ownership of the socket
344 std::thread{std::bind(
345 &do_session,
346 std::move(socket),
347 std::ref(ctx),
348 doc_root)}.detach();
349 }
350 }
351 catch (const std::exception& e)
352 {
353 std::cerr << "Error: " << e.what() << std::endl;
354 return EXIT_FAILURE;
355 }
356 }
357