summaryrefslogtreecommitdiffhomepage
path: root/https.cpp
blob: b4e77f9dbf3c5fb306c500bbe649b69ab9c34ac9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
#include "https.h"

#include "server.h"

#include <boost/beast/version.hpp>

#if BOOST_VERSION == 107100

#include "server_certificate.h"

#include <boost/beast/core.hpp>
#include <boost/beast/http.hpp>
#include <boost/beast/version.hpp>
#include <boost/beast/ssl.hpp>
#include <boost/asio/dispatch.hpp>
#include <boost/asio/strand.hpp>
#include <boost/config.hpp>
#include <algorithm>
#include <cstdlib>
#include <functional>
#include <iostream>
#include <memory>
#include <string>
#include <thread>
#include <vector>

namespace beast = boost::beast;         // from <boost/beast.hpp>
namespace http = beast::http;           // from <boost/beast/http.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>

namespace {

// Return a reasonable mime type based on the extension of a file.
beast::string_view
mime_type(beast::string_view path)
{
    using beast::iequals;
    auto const ext = [&path]
    {
        auto const pos = path.rfind(".");
        if(pos == beast::string_view::npos)
            return beast::string_view{};
        return path.substr(pos);
    }();
    if(iequals(ext, ".htm"))  return "text/html";
    if(iequals(ext, ".html")) return "text/html";
    if(iequals(ext, ".php"))  return "text/html";
    if(iequals(ext, ".css"))  return "text/css";
    if(iequals(ext, ".txt"))  return "text/plain";
    if(iequals(ext, ".js"))   return "application/javascript";
    if(iequals(ext, ".json")) return "application/json";
    if(iequals(ext, ".xml"))  return "application/xml";
    if(iequals(ext, ".swf"))  return "application/x-shockwave-flash";
    if(iequals(ext, ".flv"))  return "video/x-flv";
    if(iequals(ext, ".png"))  return "image/png";
    if(iequals(ext, ".jpe"))  return "image/jpeg";
    if(iequals(ext, ".jpeg")) return "image/jpeg";
    if(iequals(ext, ".jpg"))  return "image/jpeg";
    if(iequals(ext, ".gif"))  return "image/gif";
    if(iequals(ext, ".bmp"))  return "image/bmp";
    if(iequals(ext, ".ico"))  return "image/vnd.microsoft.icon";
    if(iequals(ext, ".tiff")) return "image/tiff";
    if(iequals(ext, ".tif"))  return "image/tiff";
    if(iequals(ext, ".svg"))  return "image/svg+xml";
    if(iequals(ext, ".svgz")) return "image/svg+xml";
    return "application/text";
}

// Append an HTTP rel-path to a local filesystem path.
// The returned path is normalized for the platform.
std::string
path_cat(
    beast::string_view base,
    beast::string_view path)
{
    if(base.empty())
        return std::string(path);
    std::string result(base);
#ifdef BOOST_MSVC
    char constexpr path_separator = '\\';
    if(result.back() == path_separator)
        result.resize(result.size() - 1);
    result.append(path.data(), path.size());
    for(auto& c : result)
        if(c == '/')
            c = path_separator;
#else
    char constexpr path_separator = '/';
    if(result.back() == path_separator)
        result.resize(result.size() - 1);
    result.append(path.data(), path.size());
#endif
    return result;
}

// This function produces an HTTP response for the given
// request. The type of the response object depends on the
// contents of the request, so the interface requires the
// caller to pass a generic lambda for receiving the response.
template<
    class Body, class Allocator,
    class Send>
void
handle_request(
    beast::string_view doc_root,
    http::request<Body, http::basic_fields<Allocator>>&& req,
    Send&& send)
{
    // Returns a bad request response
    auto const bad_request =
    [&req](beast::string_view why)
    {
        http::response<http::string_body> res{http::status::bad_request, req.version()};
        res.set(http::field::server, VersionString);
        res.set(http::field::content_type, "text/html");
        res.keep_alive(req.keep_alive());
        res.body() = std::string(why);
        res.prepare_payload();
        return res;
    };

    // Returns a not found response
    auto const not_found =
    [&req](beast::string_view target)
    {
        http::response<http::string_body> res{http::status::not_found, req.version()};
        res.set(http::field::server, VersionString);
        res.set(http::field::content_type, "text/html");
        res.keep_alive(req.keep_alive());
        res.body() = "The resource '" + std::string(target) + "' was not found.";
        res.prepare_payload();
        return res;
    };

    // Returns a server error response
    auto const server_error =
    [&req](beast::string_view what)
    {
        http::response<http::string_body> res{http::status::internal_server_error, req.version()};
        res.set(http::field::server, VersionString);
        res.set(http::field::content_type, "text/html");
        res.keep_alive(req.keep_alive());
        res.body() = "An error occurred: '" + std::string(what) + "'";
        res.prepare_payload();
        return res;
    };

    // Make sure we can handle the method
    if( req.method() != http::verb::get &&
        req.method() != http::verb::head)
        return send(bad_request("Unknown HTTP-method"));

    // Request path must be absolute and not contain "..".
    if( req.target().empty() ||
        req.target()[0] != '/' ||
        req.target().find("..") != beast::string_view::npos)
        return send(bad_request("Illegal request-target"));

    // Build the path to the requested file
    std::string path = path_cat(doc_root, req.target());
    if(req.target().back() == '/')
        path.append("index.html");

    // Attempt to open the file
    beast::error_code ec;
    http::file_body::value_type body;
    body.open(path.c_str(), beast::file_mode::scan, ec);

    // Handle the case where the file doesn't exist
    if(ec == beast::errc::no_such_file_or_directory)
        return send(not_found(req.target()));

    // Handle an unknown error
    if(ec)
        return send(server_error(ec.message()));

    // Cache the size since we need it after the move
    auto const size = body.size();

    // Respond to HEAD request
    if(req.method() == http::verb::head)
    {
        http::response<http::empty_body> res{http::status::ok, req.version()};
        res.set(http::field::server, VersionString);
        res.set(http::field::content_type, mime_type(path));
        res.content_length(size);
        res.keep_alive(req.keep_alive());
        return send(std::move(res));
    }

    // Respond to GET request
    http::response<http::file_body> res{
        std::piecewise_construct,
        std::make_tuple(std::move(body)),
        std::make_tuple(http::status::ok, req.version())};
    res.set(http::field::server, VersionString);
    res.set(http::field::content_type, mime_type(path));
    res.content_length(size);
    res.keep_alive(req.keep_alive());
    return send(std::move(res));
}

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

// Report a failure
void
fail(beast::error_code ec, char const* what)
{
    // ssl::error::stream_truncated, also known as an SSL "short read",
    // indicates the peer closed the connection without performing the
    // required closing handshake (for example, Google does this to
    // improve performance). Generally this can be a security issue,
    // but if your communication protocol is self-terminated (as
    // it is with both HTTP and WebSocket) then you may simply
    // ignore the lack of close_notify.
    //
    // https://github.com/boostorg/beast/issues/38
    //
    // https://security.stackexchange.com/questions/91435/how-to-handle-a-malicious-ssl-tls-shutdown
    //
    // When a short read would cut off the end of an HTTP message,
    // Beast returns the error beast::http::error::partial_message.
    // Therefore, if we see a short read here, it has occurred
    // after the message has been completed, so it is safe to ignore it.

    if(ec == net::ssl::error::stream_truncated)
        return;

    std::cerr << what << ": " << ec.message() << "\n";
}

// Handles an HTTP server connection
class session : public std::enable_shared_from_this<session>
{
    // This is the C++11 equivalent of a generic lambda.
    // The function object is used to send an HTTP message.
    struct send_lambda
    {
        session& self_;

        explicit
        send_lambda(session& self)
            : self_(self)
        {
        }

        template<bool isRequest, class Body, class Fields>
        void
        operator()(http::message<isRequest, Body, Fields>&& msg) const
        {
            // The lifetime of the message has to extend
            // for the duration of the async operation so
            // we use a shared_ptr to manage it.
            auto sp = std::make_shared<
                http::message<isRequest, Body, Fields>>(std::move(msg));

            // Store a type-erased version of the shared
            // pointer in the class to keep it alive.
            self_.res_ = sp;

            // Write the response
            http::async_write(
                self_.stream_,
                *sp,
                beast::bind_front_handler(
                    &session::on_write,
                    self_.shared_from_this(),
                    sp->need_eof()));
        }
    };

    beast::ssl_stream<beast::tcp_stream> stream_;
    beast::flat_buffer buffer_;
    std::shared_ptr<std::string const> doc_root_;
    http::request<http::string_body> req_;
    std::shared_ptr<void> res_;
    send_lambda lambda_;

public:
    // Take ownership of the socket
    explicit
    session(
        tcp::socket&& socket,
        ssl::context& ctx,
        std::shared_ptr<std::string const> const& doc_root)
        : stream_(std::move(socket), ctx)
        , doc_root_(doc_root)
        , lambda_(*this)
    {
    }

    // Start the asynchronous operation
    void
    run()
    {
        // We need to be executing within a strand to perform async operations
        // on the I/O objects in this session. Although not strictly necessary
        // for single-threaded contexts, this example code is written to be
        // thread-safe by default.
        net::dispatch(
            stream_.get_executor(),
            beast::bind_front_handler(
                &session::on_run,
                shared_from_this()));
    }

    void
    on_run()
    {
        // Set the timeout.
        beast::get_lowest_layer(stream_).expires_after(
            std::chrono::seconds(30));

        // Perform the SSL handshake
        stream_.async_handshake(
            ssl::stream_base::server,
            beast::bind_front_handler(
                &session::on_handshake,
                shared_from_this()));
    }

    void
    on_handshake(beast::error_code ec)
    {
        if(ec)
            return fail(ec, "handshake");

        do_read();
    }

    void
    do_read()
    {
        // Make the request empty before reading,
        // otherwise the operation behavior is undefined.
        req_ = {};

        // Set the timeout.
        beast::get_lowest_layer(stream_).expires_after(std::chrono::seconds(30));

        // Read a request
        http::async_read(stream_, buffer_, req_,
            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);

        // This means they closed the connection
        if(ec == http::error::end_of_stream)
            return do_close();

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

        // Send the response
        handle_request(*doc_root_, std::move(req_), lambda_);
    }

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

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

        if(close)
        {
            // This means we should close the connection, usually because
            // the response indicated the "Connection: close" semantic.
            return do_close();
        }

        // We're done with the response so delete it
        res_ = nullptr;

        // Read another request
        do_read();
    }

    void
    do_close()
    {
        // Set the timeout.
        beast::get_lowest_layer(stream_).expires_after(std::chrono::seconds(30));

        // Perform the SSL shutdown
        stream_.async_shutdown(
            beast::bind_front_handler(
                &session::on_shutdown,
                shared_from_this()));
    }

    void
    on_shutdown(beast::error_code ec)
    {
        if(ec)
            return fail(ec, "shutdown");

        // At this point the connection is closed gracefully
    }
};

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

// Accepts incoming connections and launches the sessions
class listener : public std::enable_shared_from_this<listener>
{
    net::io_context& ioc_;
    ssl::context& ctx_;
    tcp::acceptor acceptor_;
    std::shared_ptr<std::string const> doc_root_;

public:
    listener(
        net::io_context& ioc,
        ssl::context& ctx,
        tcp::endpoint endpoint,
        std::shared_ptr<std::string const> const& doc_root)
        : ioc_(ioc)
        , ctx_(ctx)
        , acceptor_(ioc)
        , doc_root_(doc_root)
    {
        beast::error_code ec;

        // Open the acceptor
        acceptor_.open(endpoint.protocol(), ec);
        if(ec)
        {
            fail(ec, "open");
            return;
        }

        // Allow address reuse
        acceptor_.set_option(net::socket_base::reuse_address(true), ec);
        if(ec)
        {
            fail(ec, "set_option");
            return;
        }

        // Bind to the server address
        acceptor_.bind(endpoint, ec);
        if(ec)
        {
            fail(ec, "bind");
            return;
        }

        // Start listening for connections
        acceptor_.listen(
            net::socket_base::max_listen_connections, ec);
        if(ec)
        {
            fail(ec, "listen");
            return;
        }
    }

    // Start accepting incoming connections
    void
    run()
    {
        do_accept();
    }

private:
    void
    do_accept()
    {
        // The new connection gets its own strand
        acceptor_.async_accept(
            net::make_strand(ioc_),
            beast::bind_front_handler(
                &listener::on_accept,
                shared_from_this()));
    }

    void
    on_accept(beast::error_code ec, tcp::socket socket)
    {
        if(ec)
        {
            fail(ec, "accept");
        }
        else
        {
            // Create the session and run it
            std::make_shared<session>(
                std::move(socket),
                ctx_,
                doc_root_)->run();
        }

        // Accept another connection
        do_accept();
    }
};

} // anonymous namespace
//------------------------------------------------------------------------------

namespace HTTPS {

Server::Server(Config& config, boost::asio::io_context& ioc, const Socket& socket): ::Server(config, ioc), m_socket(socket)
{
 // This holds the self-signed certificate used by the server
 load_server_certificate(m_ctx, m_socket.cert_path, m_socket.key_path);
}

Server::~Server()
{
}

int Server::start()
{
 // TODO: Config
 auto const address = net::ip::make_address(m_socket.address);
 auto const port = static_cast<unsigned short>(std::atoi(m_socket.port.data()));
 auto const doc_root = std::make_shared<std::string>(m_config.Sites()[0].paths[0].params.at("target"));

 // Create and launch a listening port
 std::make_shared<listener>(
     m_ioc,
     m_ctx,
     tcp::endpoint{address, port},
     doc_root)->run();

 return EXIT_SUCCESS;
}

} // namespace HTTPS
#endif