xref: /openbmc/bmcweb/http/http_connection.hpp (revision 4cee35e7) 
1 #pragma once
2 #include "bmcweb_config.h"
3 
4 #include "authorization.hpp"
5 #include "http_response.hpp"
6 #include "http_utility.hpp"
7 #include "logging.hpp"
8 #include "utility.hpp"
9 
10 #include <boost/algorithm/string.hpp>
11 #include <boost/algorithm/string/predicate.hpp>
12 #include <boost/asio/io_context.hpp>
13 #include <boost/asio/ip/tcp.hpp>
14 #include <boost/asio/ssl/stream.hpp>
15 #include <boost/asio/steady_timer.hpp>
16 #include <boost/beast/core/flat_static_buffer.hpp>
17 #include <boost/beast/ssl/ssl_stream.hpp>
18 #include <boost/beast/websocket.hpp>
19 #include <boost/url/url_view.hpp>
20 #include <json_html_serializer.hpp>
21 #include <security_headers.hpp>
22 #include <ssl_key_handler.hpp>
23 
24 #include <atomic>
25 #include <chrono>
26 #include <vector>
27 
28 namespace crow
29 {
30 
31 inline void prettyPrintJson(crow::Response& res)
32 {
33     json_html_util::dumpHtml(res.body(), res.jsonValue);
34 
35     res.addHeader("Content-Type", "text/html;charset=UTF-8");
36 }
37 
38 static int connectionCount = 0;
39 
40 // request body limit size set by the bmcwebHttpReqBodyLimitMb option
41 constexpr uint64_t httpReqBodyLimit =
42     1024UL * 1024UL * bmcwebHttpReqBodyLimitMb;
43 
44 constexpr uint64_t loggedOutPostBodyLimit = 4096;
45 
46 constexpr uint32_t httpHeaderLimit = 8192;
47 
48 template <typename Adaptor, typename Handler>
49 class Connection :
50     public std::enable_shared_from_this<Connection<Adaptor, Handler>>
51 {
52   public:
53     Connection(Handler* handlerIn, boost::asio::steady_timer&& timerIn,
54                std::function<std::string()>& getCachedDateStrF,
55                Adaptor adaptorIn) :
56         adaptor(std::move(adaptorIn)),
57         handler(handlerIn), timer(std::move(timerIn)),
58         getCachedDateStr(getCachedDateStrF)
59     {
60         parser.emplace(std::piecewise_construct, std::make_tuple());
61         parser->body_limit(httpReqBodyLimit);
62         parser->header_limit(httpHeaderLimit);
63 
64 #ifdef BMCWEB_ENABLE_MUTUAL_TLS_AUTHENTICATION
65         prepareMutualTls();
66 #endif // BMCWEB_ENABLE_MUTUAL_TLS_AUTHENTICATION
67 
68         connectionCount++;
69 
70         BMCWEB_LOG_DEBUG << this << " Connection open, total "
71                          << connectionCount;
72     }
73 
74     ~Connection()
75     {
76         res.setCompleteRequestHandler(nullptr);
77         cancelDeadlineTimer();
78 
79         connectionCount--;
80         BMCWEB_LOG_DEBUG << this << " Connection closed, total "
81                          << connectionCount;
82     }
83 
84     Connection(const Connection&) = delete;
85     Connection(Connection&&) = delete;
86     Connection& operator=(const Connection&) = delete;
87     Connection& operator=(Connection&&) = delete;
88 
89     void prepareMutualTls()
90     {
91         std::error_code error;
92         std::filesystem::path caPath(ensuressl::trustStorePath);
93         auto caAvailable = !std::filesystem::is_empty(caPath, error);
94         caAvailable = caAvailable && !error;
95         if (caAvailable && persistent_data::SessionStore::getInstance()
96                                .getAuthMethodsConfig()
97                                .tls)
98         {
99             adaptor.set_verify_mode(boost::asio::ssl::verify_peer);
100             std::string id = "bmcweb";
101 
102             const char* cStr = id.c_str();
103             // NOLINTNEXTLINE(cppcoreguidelines-pro-type-reinterpret-cast)
104             const auto* idC = reinterpret_cast<const unsigned char*>(cStr);
105             int ret = SSL_set_session_id_context(
106                 adaptor.native_handle(), idC,
107                 static_cast<unsigned int>(id.length()));
108             if (ret == 0)
109             {
110                 BMCWEB_LOG_ERROR << this << " failed to set SSL id";
111             }
112         }
113 
114         adaptor.set_verify_callback([this](
115                                         bool preverified,
116                                         boost::asio::ssl::verify_context& ctx) {
117             // do nothing if TLS is disabled
118             if (!persistent_data::SessionStore::getInstance()
119                      .getAuthMethodsConfig()
120                      .tls)
121             {
122                 BMCWEB_LOG_DEBUG << this << " TLS auth_config is disabled";
123                 return true;
124             }
125 
126             // We always return true to allow full auth flow
127             if (!preverified)
128             {
129                 BMCWEB_LOG_DEBUG << this << " TLS preverification failed.";
130                 return true;
131             }
132 
133             X509_STORE_CTX* cts = ctx.native_handle();
134             if (cts == nullptr)
135             {
136                 BMCWEB_LOG_DEBUG << this << " Cannot get native TLS handle.";
137                 return true;
138             }
139 
140             // Get certificate
141             X509* peerCert =
142                 X509_STORE_CTX_get_current_cert(ctx.native_handle());
143             if (peerCert == nullptr)
144             {
145                 BMCWEB_LOG_DEBUG << this
146                                  << " Cannot get current TLS certificate.";
147                 return true;
148             }
149 
150             // Check if certificate is OK
151             int error = X509_STORE_CTX_get_error(cts);
152             if (error != X509_V_OK)
153             {
154                 BMCWEB_LOG_INFO << this << " Last TLS error is: " << error;
155                 return true;
156             }
157             // Check that we have reached final certificate in chain
158             int32_t depth = X509_STORE_CTX_get_error_depth(cts);
159             if (depth != 0)
160 
161             {
162                 BMCWEB_LOG_DEBUG
163                     << this << " Certificate verification in progress (depth "
164                     << depth << "), waiting to reach final depth";
165                 return true;
166             }
167 
168             BMCWEB_LOG_DEBUG << this
169                              << " Certificate verification of final depth";
170 
171             // Verify KeyUsage
172             bool isKeyUsageDigitalSignature = false;
173             bool isKeyUsageKeyAgreement = false;
174 
175             ASN1_BIT_STRING* usage = static_cast<ASN1_BIT_STRING*>(
176                 X509_get_ext_d2i(peerCert, NID_key_usage, nullptr, nullptr));
177 
178             if (usage == nullptr)
179             {
180                 BMCWEB_LOG_DEBUG << this << " TLS usage is null";
181                 return true;
182             }
183 
184             for (int i = 0; i < usage->length; i++)
185             {
186                 // NOLINTNEXTLINE(cppcoreguidelines-pro-bounds-pointer-arithmetic)
187                 unsigned char usageChar = usage->data[i];
188                 if (KU_DIGITAL_SIGNATURE & usageChar)
189                 {
190                     isKeyUsageDigitalSignature = true;
191                 }
192                 if (KU_KEY_AGREEMENT & usageChar)
193                 {
194                     isKeyUsageKeyAgreement = true;
195                 }
196             }
197             ASN1_BIT_STRING_free(usage);
198 
199             if (!isKeyUsageDigitalSignature || !isKeyUsageKeyAgreement)
200             {
201                 BMCWEB_LOG_DEBUG << this
202                                  << " Certificate ExtendedKeyUsage does "
203                                     "not allow provided certificate to "
204                                     "be used for user authentication";
205                 return true;
206             }
207 
208             // Determine that ExtendedKeyUsage includes Client Auth
209 
210             stack_st_ASN1_OBJECT* extUsage =
211                 static_cast<stack_st_ASN1_OBJECT*>(X509_get_ext_d2i(
212                     peerCert, NID_ext_key_usage, nullptr, nullptr));
213 
214             if (extUsage == nullptr)
215             {
216                 BMCWEB_LOG_DEBUG << this << " TLS extUsage is null";
217                 return true;
218             }
219 
220             bool isExKeyUsageClientAuth = false;
221             for (int i = 0; i < sk_ASN1_OBJECT_num(extUsage); i++)
222             {
223                 // NOLINTNEXTLINE(cppcoreguidelines-pro-type-cstyle-cast)
224                 int nid = OBJ_obj2nid(sk_ASN1_OBJECT_value(extUsage, i));
225                 if (NID_client_auth == nid)
226                 {
227                     isExKeyUsageClientAuth = true;
228                     break;
229                 }
230             }
231             sk_ASN1_OBJECT_free(extUsage);
232 
233             // Certificate has to have proper key usages set
234             if (!isExKeyUsageClientAuth)
235             {
236                 BMCWEB_LOG_DEBUG << this
237                                  << " Certificate ExtendedKeyUsage does "
238                                     "not allow provided certificate to "
239                                     "be used for user authentication";
240                 return true;
241             }
242             std::string sslUser;
243             // Extract username contained in CommonName
244             sslUser.resize(256, '\0');
245 
246             int status = X509_NAME_get_text_by_NID(
247                 X509_get_subject_name(peerCert), NID_commonName, sslUser.data(),
248                 static_cast<int>(sslUser.size()));
249 
250             if (status == -1)
251             {
252                 BMCWEB_LOG_DEBUG
253                     << this << " TLS cannot get username to create session";
254                 return true;
255             }
256 
257             size_t lastChar = sslUser.find('\0');
258             if (lastChar == std::string::npos || lastChar == 0)
259             {
260                 BMCWEB_LOG_DEBUG << this << " Invalid TLS user name";
261                 return true;
262             }
263             sslUser.resize(lastChar);
264             std::string unsupportedClientId;
265             sessionIsFromTransport = true;
266             userSession = persistent_data::SessionStore::getInstance()
267                               .generateUserSession(
268                                   sslUser, req->ipAddress, unsupportedClientId,
269                                   persistent_data::PersistenceType::TIMEOUT);
270             if (userSession != nullptr)
271             {
272                 BMCWEB_LOG_DEBUG
273                     << this
274                     << " Generating TLS session: " << userSession->uniqueId;
275             }
276             return true;
277         });
278     }
279 
280     Adaptor& socket()
281     {
282         return adaptor;
283     }
284 
285     void start()
286     {
287         if (connectionCount >= 100)
288         {
289             BMCWEB_LOG_CRITICAL << this << "Max connection count exceeded.";
290             return;
291         }
292 
293         startDeadline();
294 
295         // TODO(ed) Abstract this to a more clever class with the idea of an
296         // asynchronous "start"
297         if constexpr (std::is_same_v<Adaptor,
298                                      boost::beast::ssl_stream<
299                                          boost::asio::ip::tcp::socket>>)
300         {
301             adaptor.async_handshake(boost::asio::ssl::stream_base::server,
302                                     [this, self(shared_from_this())](
303                                         const boost::system::error_code& ec) {
304                                         if (ec)
305                                         {
306                                             return;
307                                         }
308                                         doReadHeaders();
309                                     });
310         }
311         else
312         {
313             doReadHeaders();
314         }
315     }
316 
317     void handle()
318     {
319         std::error_code reqEc;
320         crow::Request& thisReq = req.emplace(parser->release(), reqEc);
321         if (reqEc)
322         {
323             BMCWEB_LOG_DEBUG << "Request failed to construct" << reqEc;
324             return;
325         }
326         thisReq.session = userSession;
327 
328         // Fetch the client IP address
329         readClientIp();
330 
331         // Check for HTTP version 1.1.
332         if (thisReq.version() == 11)
333         {
334             if (thisReq.getHeaderValue(boost::beast::http::field::host).empty())
335             {
336                 res.result(boost::beast::http::status::bad_request);
337                 completeRequest(res);
338                 return;
339             }
340         }
341 
342         BMCWEB_LOG_INFO << "Request: "
343                         << " " << this << " HTTP/" << thisReq.version() / 10
344                         << "." << thisReq.version() % 10 << ' '
345                         << thisReq.methodString() << " " << thisReq.target()
346                         << " " << thisReq.ipAddress.to_string();
347 
348         res.isAliveHelper = [this]() -> bool { return isAlive(); };
349 
350         thisReq.ioService = static_cast<decltype(thisReq.ioService)>(
351             &adaptor.get_executor().context());
352 
353         if (res.completed)
354         {
355             completeRequest(res);
356             return;
357         }
358 #ifndef BMCWEB_INSECURE_DISABLE_AUTHENTICATION
359         if (!crow::authorization::isOnAllowlist(req->url, req->method()) &&
360             thisReq.session == nullptr)
361         {
362             BMCWEB_LOG_WARNING << "Authentication failed";
363             forward_unauthorized::sendUnauthorized(
364                 req->url, req->getHeaderValue("User-Agent"),
365                 req->getHeaderValue("Accept"), res);
366             completeRequest(res);
367             return;
368         }
369 #endif // BMCWEB_INSECURE_DISABLE_AUTHENTICATION
370         auto asyncResp = std::make_shared<bmcweb::AsyncResp>();
371         BMCWEB_LOG_DEBUG << "Setting completion handler";
372         asyncResp->res.setCompleteRequestHandler(
373             [self(shared_from_this())](crow::Response& thisRes) {
374                 self->completeRequest(thisRes);
375             });
376 
377         if (thisReq.isUpgrade() &&
378             boost::iequals(
379                 thisReq.getHeaderValue(boost::beast::http::field::upgrade),
380                 "websocket"))
381         {
382             handler->handleUpgrade(thisReq, res, std::move(adaptor));
383             // delete lambda with self shared_ptr
384             // to enable connection destruction
385             asyncResp->res.setCompleteRequestHandler(nullptr);
386             return;
387         }
388         handler->handle(thisReq, asyncResp);
389     }
390 
391     bool isAlive()
392     {
393         if constexpr (std::is_same_v<Adaptor,
394                                      boost::beast::ssl_stream<
395                                          boost::asio::ip::tcp::socket>>)
396         {
397             return adaptor.next_layer().is_open();
398         }
399         else
400         {
401             return adaptor.is_open();
402         }
403     }
404     void close()
405     {
406         if constexpr (std::is_same_v<Adaptor,
407                                      boost::beast::ssl_stream<
408                                          boost::asio::ip::tcp::socket>>)
409         {
410             adaptor.next_layer().close();
411             if (sessionIsFromTransport && userSession != nullptr)
412             {
413                 BMCWEB_LOG_DEBUG
414                     << this
415                     << " Removing TLS session: " << userSession->uniqueId;
416                 persistent_data::SessionStore::getInstance().removeSession(
417                     userSession);
418             }
419         }
420         else
421         {
422             adaptor.close();
423         }
424     }
425 
426     void completeRequest(crow::Response& thisRes)
427     {
428         if (!req)
429         {
430             return;
431         }
432         res = std::move(thisRes);
433         BMCWEB_LOG_INFO << "Response: " << this << ' ' << req->url << ' '
434                         << res.resultInt() << " keepalive=" << req->keepAlive();
435 
436         addSecurityHeaders(*req, res);
437 
438         crow::authorization::cleanupTempSession(*req);
439 
440         if (!isAlive())
441         {
442             // BMCWEB_LOG_DEBUG << this << " delete (socket is closed) " <<
443             // isReading
444             // << ' ' << isWriting;
445             // delete this;
446 
447             // delete lambda with self shared_ptr
448             // to enable connection destruction
449             res.setCompleteRequestHandler(nullptr);
450             return;
451         }
452         if (res.body().empty() && !res.jsonValue.empty())
453         {
454             if (http_helpers::requestPrefersHtml(req->getHeaderValue("Accept")))
455             {
456                 prettyPrintJson(res);
457             }
458             else
459             {
460                 res.jsonMode();
461                 res.body() = res.jsonValue.dump(
462                     2, ' ', true, nlohmann::json::error_handler_t::replace);
463             }
464         }
465 
466         if (res.resultInt() >= 400 && res.body().empty())
467         {
468             res.body() = std::string(res.reason());
469         }
470 
471         if (res.result() == boost::beast::http::status::no_content)
472         {
473             // Boost beast throws if content is provided on a no-content
474             // response.  Ideally, this would never happen, but in the case that
475             // it does, we don't want to throw.
476             BMCWEB_LOG_CRITICAL
477                 << this << " Response content provided but code was no-content";
478             res.body().clear();
479         }
480 
481         res.addHeader(boost::beast::http::field::date, getCachedDateStr());
482 
483         res.keepAlive(req->keepAlive());
484 
485         doWrite(res);
486 
487         // delete lambda with self shared_ptr
488         // to enable connection destruction
489         res.setCompleteRequestHandler(nullptr);
490     }
491 
492     void readClientIp()
493     {
494         boost::asio::ip::address ip;
495         boost::system::error_code ec = getClientIp(ip);
496         if (ec)
497         {
498             return;
499         }
500         req->ipAddress = ip;
501     }
502 
503     boost::system::error_code getClientIp(boost::asio::ip::address& ip)
504     {
505         boost::system::error_code ec;
506         BMCWEB_LOG_DEBUG << "Fetch the client IP address";
507         boost::asio::ip::tcp::endpoint endpoint =
508             boost::beast::get_lowest_layer(adaptor).remote_endpoint(ec);
509 
510         if (ec)
511         {
512             // If remote endpoint fails keep going. "ClientOriginIPAddress"
513             // will be empty.
514             BMCWEB_LOG_ERROR << "Failed to get the client's IP Address. ec : "
515                              << ec;
516             return ec;
517         }
518         ip = endpoint.address();
519         return ec;
520     }
521 
522   private:
523     void doReadHeaders()
524     {
525         BMCWEB_LOG_DEBUG << this << " doReadHeaders";
526 
527         // Clean up any previous Connection.
528         boost::beast::http::async_read_header(
529             adaptor, buffer, *parser,
530             [this,
531              self(shared_from_this())](const boost::system::error_code& ec,
532                                        std::size_t bytesTransferred) {
533                 BMCWEB_LOG_DEBUG << this << " async_read_header "
534                                  << bytesTransferred << " Bytes";
535                 bool errorWhileReading = false;
536                 if (ec)
537                 {
538                     errorWhileReading = true;
539                     if (ec == boost::asio::error::eof)
540                     {
541                         BMCWEB_LOG_WARNING
542                             << this << " Error while reading: " << ec.message();
543                     }
544                     else
545                     {
546                         BMCWEB_LOG_ERROR
547                             << this << " Error while reading: " << ec.message();
548                     }
549                 }
550                 else
551                 {
552                     // if the adaptor isn't open anymore, and wasn't handed to a
553                     // websocket, treat as an error
554                     if (!isAlive() &&
555                         !boost::beast::websocket::is_upgrade(parser->get()))
556                     {
557                         errorWhileReading = true;
558                     }
559                 }
560 
561                 cancelDeadlineTimer();
562 
563                 if (errorWhileReading)
564                 {
565                     close();
566                     BMCWEB_LOG_DEBUG << this << " from read(1)";
567                     return;
568                 }
569 
570                 readClientIp();
571 
572                 boost::asio::ip::address ip;
573                 if (getClientIp(ip))
574                 {
575                     BMCWEB_LOG_DEBUG << "Unable to get client IP";
576                 }
577                 sessionIsFromTransport = false;
578 #ifndef BMCWEB_INSECURE_DISABLE_AUTHENTICATION
579                 boost::beast::http::verb method = parser->get().method();
580                 userSession = crow::authorization::authenticate(
581                     ip, res, method, parser->get().base(), userSession);
582 
583                 bool loggedIn = userSession != nullptr;
584                 if (!loggedIn)
585                 {
586                     const boost::optional<uint64_t> contentLength =
587                         parser->content_length();
588                     if (contentLength &&
589                         *contentLength > loggedOutPostBodyLimit)
590                     {
591                         BMCWEB_LOG_DEBUG << "Content length greater than limit "
592                                          << *contentLength;
593                         close();
594                         return;
595                     }
596 
597                     BMCWEB_LOG_DEBUG << "Starting quick deadline";
598                 }
599 #endif // BMCWEB_INSECURE_DISABLE_AUTHENTICATION
600 
601                 doRead();
602             });
603     }
604 
605     void doRead()
606     {
607         BMCWEB_LOG_DEBUG << this << " doRead";
608         startDeadline();
609         boost::beast::http::async_read(
610             adaptor, buffer, *parser,
611             [this,
612              self(shared_from_this())](const boost::system::error_code& ec,
613                                        std::size_t bytesTransferred) {
614                 BMCWEB_LOG_DEBUG << this << " async_read " << bytesTransferred
615                                  << " Bytes";
616                 cancelDeadlineTimer();
617                 if (ec)
618                 {
619                     BMCWEB_LOG_ERROR
620                         << this << " Error while reading: " << ec.message();
621                     close();
622                     BMCWEB_LOG_DEBUG << this << " from read(1)";
623                     return;
624                 }
625                 handle();
626             });
627     }
628 
629     void doWrite(crow::Response& thisRes)
630     {
631         BMCWEB_LOG_DEBUG << this << " doWrite";
632         thisRes.preparePayload();
633         serializer.emplace(*thisRes.stringResponse);
634         startDeadline();
635         boost::beast::http::async_write(
636             adaptor, *serializer,
637             [this,
638              self(shared_from_this())](const boost::system::error_code& ec,
639                                        std::size_t bytesTransferred) {
640                 BMCWEB_LOG_DEBUG << this << " async_write " << bytesTransferred
641                                  << " bytes";
642 
643                 cancelDeadlineTimer();
644 
645                 if (ec)
646                 {
647                     BMCWEB_LOG_DEBUG << this << " from write(2)";
648                     return;
649                 }
650                 if (!res.keepAlive())
651                 {
652                     close();
653                     BMCWEB_LOG_DEBUG << this << " from write(1)";
654                     return;
655                 }
656 
657                 serializer.reset();
658                 BMCWEB_LOG_DEBUG << this << " Clearing response";
659                 res.clear();
660                 parser.emplace(std::piecewise_construct, std::make_tuple());
661                 parser->body_limit(httpReqBodyLimit); // reset body limit for
662                                                       // newly created parser
663                 buffer.consume(buffer.size());
664 
665                 // If the session was built from the transport, we don't need to
666                 // clear it.  All other sessions are generated per request.
667                 if (!sessionIsFromTransport)
668                 {
669                     userSession = nullptr;
670                 }
671 
672                 // Destroy the Request via the std::optional
673                 req.reset();
674                 doReadHeaders();
675             });
676     }
677 
678     void cancelDeadlineTimer()
679     {
680         timer.cancel();
681     }
682 
683     void startDeadline()
684     {
685         cancelDeadlineTimer();
686 
687         std::chrono::seconds timeout(15);
688         // allow slow uploads for logged in users
689         bool loggedIn = userSession != nullptr;
690         if (loggedIn)
691         {
692             timeout = std::chrono::seconds(60);
693             return;
694         }
695 
696         std::weak_ptr<Connection<Adaptor, Handler>> weakSelf = weak_from_this();
697         timer.expires_after(timeout);
698         timer.async_wait([weakSelf](const boost::system::error_code ec) {
699             // Note, we are ignoring other types of errors here;  If the timer
700             // failed for any reason, we should still close the connection
701 
702             std::shared_ptr<Connection<Adaptor, Handler>> self =
703                 weakSelf.lock();
704             if (!self)
705             {
706                 BMCWEB_LOG_CRITICAL << self << " Failed to capture connection";
707                 return;
708             }
709             if (ec == boost::asio::error::operation_aborted)
710             {
711                 // Canceled wait means the path succeeeded.
712                 return;
713             }
714             if (ec)
715             {
716                 BMCWEB_LOG_CRITICAL << self << " timer failed " << ec;
717             }
718 
719             BMCWEB_LOG_WARNING << self << "Connection timed out, closing";
720 
721             self->close();
722         });
723 
724         BMCWEB_LOG_DEBUG << this << " timer started";
725     }
726 
727     Adaptor adaptor;
728     Handler* handler;
729     // Making this a std::optional allows it to be efficiently destroyed and
730     // re-created on Connection reset
731     std::optional<
732         boost::beast::http::request_parser<boost::beast::http::string_body>>
733         parser;
734 
735     boost::beast::flat_static_buffer<8192> buffer;
736 
737     std::optional<boost::beast::http::response_serializer<
738         boost::beast::http::string_body>>
739         serializer;
740 
741     std::optional<crow::Request> req;
742     crow::Response res;
743 
744     bool sessionIsFromTransport = false;
745     std::shared_ptr<persistent_data::UserSession> userSession;
746 
747     boost::asio::steady_timer timer;
748 
749     std::function<std::string()>& getCachedDateStr;
750 
751     using std::enable_shared_from_this<
752         Connection<Adaptor, Handler>>::shared_from_this;
753 
754     using std::enable_shared_from_this<
755         Connection<Adaptor, Handler>>::weak_from_this;
756 };
757 } // namespace crow
758