src/webui/webapplication.cpp

   1 /*
   2  * Bittorrent Client using Qt and libtorrent.
   3  * Copyright (C) 2014-2024  Vladimir Golovnev <glassez@yandex.ru>
   4  * Copyright (C) 2024  Radu Carpa <radu.carpa@cern.ch>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19  *
  20  * In addition, as a special exception, the copyright holders give permission to
  21  * link this program with the OpenSSL project's "OpenSSL" library (or with
  22  * modified versions of it that use the same license as the "OpenSSL" library),
  23  * and distribute the linked executables. You must obey the GNU General Public
  24  * License in all respects for all of the code used other than "OpenSSL".  If you
  25  * modify file(s), you may extend this exception to your version of the file(s),
  26  * but you are not obligated to do so. If you do not wish to do so, delete this
  27  * exception statement from your version.
  28  */
  29
  30 #include "webapplication.h"
  31
  32 #include <algorithm>
  33 #include <chrono>
  34
  35 #include <QDateTime>
  36 #include <QDebug>
  37 #include <QDir>
  38 #include <QFileInfo>
  39 #include <QJsonDocument>
  40 #include <QMetaObject>
  41 #include <QMimeDatabase>
  42 #include <QMimeType>
  43 #include <QNetworkCookie>
  44 #include <QRegularExpression>
  45 #include <QThread>
  46 #include <QTimer>
  47 #include <QUrl>
  48
  49 #include "base/algorithm.h"
  50 #include "base/bittorrent/torrentcreationmanager.h"
  51 #include "base/http/httperror.h"
  52 #include "base/logger.h"
  53 #include "base/preferences.h"
  54 #include "base/types.h"
  55 #include "base/utils/fs.h"
  56 #include "base/utils/io.h"
  57 #include "base/utils/misc.h"
  58 #include "base/utils/random.h"
  59 #include "base/utils/string.h"
  60 #include "api/apierror.h"
  61 #include "api/appcontroller.h"
  62 #include "api/authcontroller.h"
  63 #include "api/logcontroller.h"
  64 #include "api/rsscontroller.h"
  65 #include "api/searchcontroller.h"
  66 #include "api/synccontroller.h"
  67 #include "api/torrentcreatorcontroller.h"
  68 #include "api/torrentscontroller.h"
  69 #include "api/transfercontroller.h"
  70 #include "freediskspacechecker.h"
  71
  72 const int MAX_ALLOWED_FILESIZE = 10 * 1024 * 1024;
  73 const QString DEFAULT_SESSION_COOKIE_NAME = u"SID"_s;
  74
  75 const QString WWW_FOLDER = u":/www"_s;
  76 const QString PUBLIC_FOLDER = u"/public"_s;
  77 const QString PRIVATE_FOLDER = u"/private"_s;
  78
  79 using namespace std::chrono_literals;
  80
  81 const std::chrono::seconds FREEDISKSPACE_CHECK_TIMEOUT = 30s;
  82
  83 namespace
  84 {
  85     QStringMap parseCookie(const QStringView cookieStr)
  86     {
  87         // [rfc6265] 4.2.1. Syntax
  88         QStringMap ret;
  89         const QList<QStringView> cookies = cookieStr.split(u';', Qt::SkipEmptyParts);
  90
  91         for (const auto &cookie : cookies)
  92         {
  93             const int idx = cookie.indexOf(u'=');
  94             if (idx < 0)
  95                 continue;
  96
  97             const QString name = cookie.left(idx).trimmed().toString();
  98             const QString value = Utils::String::unquote(cookie.mid(idx + 1).trimmed()).toString();
  99             ret.insert(name, value);
 100         }
 101         return ret;
 102     }
 103
 104     QUrl urlFromHostHeader(const QString &hostHeader)
 105     {
 106         if (!hostHeader.contains(u"://"))
 107             return {u"http://"_s + hostHeader};
 108         return hostHeader;
 109     }
 110
 111     QString getCachingInterval(QString contentType)
 112     {
 113         contentType = contentType.toLower();
 114
 115         if (contentType.startsWith(u"image/"))
 116             return u"private, max-age=604800"_s;  // 1 week
 117
 118         if ((contentType == Http::CONTENT_TYPE_CSS) || (contentType == Http::CONTENT_TYPE_JS))
 119         {
 120             // short interval in case of program update
 121             return u"private, max-age=43200"_s;  // 12 hrs
 122         }
 123
 124         return u"no-store"_s;
 125     }
 126
 127     QString createLanguagesOptionsHtml()
 128     {
 129         // List language files
 130         const QStringList langFiles = QDir(u":/www/translations"_s)
 131             .entryList({u"webui_*.qm"_s}, QDir::Files, QDir::Name);
 132
 133         QStringList languages;
 134         languages.reserve(langFiles.size());
 135
 136         for (const QString &langFile : langFiles)
 137         {
 138             const auto langCode = QStringView(langFile).sliced(6).chopped(3); // remove "webui_" and ".qm"
 139             const QString entry = u"<option value=\"%1\">%2</option>"_s
 140                 .arg(langCode, Utils::Misc::languageToLocalizedString(langCode));
 141             languages.append(entry);
 142         }
 143
 144         return languages.join(u'\n');
 145     }
 146
 147     bool isValidCookieName(const QString &cookieName)
 148     {
 149         if (cookieName.isEmpty() || (cookieName.size() > 128))
 150             return false;
 151
 152         const QRegularExpression invalidNameRegex {u"[^a-zA-Z0-9_\\-]"_s};
 153         if (invalidNameRegex.match(cookieName).hasMatch())
 154             return false;
 155
 156         return true;
 157     }
 158 }
 159
 160 WebApplication::WebApplication(IApplication *app, QObject *parent)
 161     : ApplicationComponent(app, parent)
 162     , m_cacheID {QString::number(Utils::Random::rand(), 36)}
 163     , m_authController {new AuthController(this, app, this)}
 164     , m_workerThread {new QThread}
 165     , m_freeDiskSpaceChecker {new FreeDiskSpaceChecker}
 166     , m_freeDiskSpaceCheckingTimer {new QTimer(this)}
 167     , m_torrentCreationManager {new BitTorrent::TorrentCreationManager(app, this)}
 168 {
 169     declarePublicAPI(u"auth/login"_s);
 170
 171     configure();
 172     connect(Preferences::instance(), &Preferences::changed, this, &WebApplication::configure);
 173
 174     m_sessionCookieName = Preferences::instance()->getWebAPISessionCookieName();
 175     if (!isValidCookieName(m_sessionCookieName))
 176     {
 177         if (!m_sessionCookieName.isEmpty())
 178         {
 179             LogMsg(tr("Unacceptable session cookie name is specified: '%1'. Default one is used.")
 180                    .arg(m_sessionCookieName), Log::WARNING);
 181         }
 182         m_sessionCookieName = DEFAULT_SESSION_COOKIE_NAME;
 183     }
 184
 185     m_freeDiskSpaceChecker->moveToThread(m_workerThread.get());
 186     connect(m_workerThread.get(), &QThread::finished, m_freeDiskSpaceChecker, &QObject::deleteLater);
 187     m_workerThread->start();
 188
 189     m_freeDiskSpaceCheckingTimer->setInterval(FREEDISKSPACE_CHECK_TIMEOUT);
 190     m_freeDiskSpaceCheckingTimer->setSingleShot(true);
 191     connect(m_freeDiskSpaceCheckingTimer, &QTimer::timeout, m_freeDiskSpaceChecker, &FreeDiskSpaceChecker::check);
 192     connect(m_freeDiskSpaceChecker, &FreeDiskSpaceChecker::checked, m_freeDiskSpaceCheckingTimer, qOverload<>(&QTimer::start));
 193     QMetaObject::invokeMethod(m_freeDiskSpaceChecker, &FreeDiskSpaceChecker::check);
 194 }
 195
 196 WebApplication::~WebApplication()
 197 {
 198     // cleanup sessions data
 199     qDeleteAll(m_sessions);
 200 }
 201
 202 void WebApplication::sendWebUIFile()
 203 {
 204     if (request().path.contains(u'\\'))
 205         throw BadRequestHTTPError();
 206
 207     if (const QList<QStringView> pathItems = QStringView(request().path).split(u'/', Qt::SkipEmptyParts)
 208             ; pathItems.contains(u".") || pathItems.contains(u".."))
 209     {
 210         throw BadRequestHTTPError();
 211     }
 212
 213     const QString path = (request().path != u"/")
 214         ? request().path
 215         : u"/index.html"_s;
 216
 217     Path localPath = m_rootFolder
 218                 / Path(session() ? PRIVATE_FOLDER : PUBLIC_FOLDER)
 219                 / Path(path);
 220     if (!localPath.exists() && session())
 221     {
 222         // try to send public file if there is no private one
 223         localPath = m_rootFolder / Path(PUBLIC_FOLDER) / Path(path);
 224     }
 225
 226     if (m_isAltUIUsed)
 227     {
 228         if (!Utils::Fs::isRegularFile(localPath))
 229             throw InternalServerErrorHTTPError(tr("Unacceptable file type, only regular file is allowed."));
 230
 231         const QString rootFolder = m_rootFolder.data();
 232
 233         QFileInfo fileInfo {localPath.parentPath().data()};
 234         while (fileInfo.path() != rootFolder)
 235         {
 236             if (fileInfo.isSymLink())
 237                 throw InternalServerErrorHTTPError(tr("Symlinks inside alternative UI folder are forbidden."));
 238
 239             fileInfo.setFile(fileInfo.path());
 240         }
 241     }
 242
 243     sendFile(localPath);
 244 }
 245
 246 void WebApplication::translateDocument(QString &data) const
 247 {
 248     const QRegularExpression regex(u"QBT_TR\\((([^\\)]|\\)(?!QBT_TR))+)\\)QBT_TR\\[CONTEXT=([a-zA-Z_][a-zA-Z0-9_]*)\\]"_s);
 249
 250     int i = 0;
 251     bool found = true;
 252     while (i < data.size() && found)
 253     {
 254         QRegularExpressionMatch regexMatch;
 255         i = data.indexOf(regex, i, &regexMatch);
 256         if (i >= 0)
 257         {
 258             const QString sourceText = regexMatch.captured(1);
 259             const QString context = regexMatch.captured(3);
 260
 261             const QString loadedText = m_translationFileLoaded
 262                 ? m_translator.translate(context.toUtf8().constData(), sourceText.toUtf8().constData())
 263                 : QString();
 264             // `loadedText` is empty when translation is not provided
 265             // it should fallback to `sourceText`
 266             QString translation = loadedText.isEmpty() ? sourceText : loadedText;
 267
 268             // Use HTML code for quotes to prevent issues with JS
 269             translation.replace(u'\'', u"&#39;"_s);
 270             translation.replace(u'\"', u"&#34;"_s);
 271
 272             data.replace(i, regexMatch.capturedLength(), translation);
 273             i += translation.length();
 274         }
 275         else
 276         {
 277             found = false; // no more translatable strings
 278         }
 279
 280         data.replace(u"${LANG}"_s, m_currentLocale.left(2));
 281         data.replace(u"${CACHEID}"_s, m_cacheID);
 282     }
 283 }
 284
 285 WebSession *WebApplication::session()
 286 {
 287     return m_currentSession;
 288 }
 289
 290 const Http::Request &WebApplication::request() const
 291 {
 292     return m_request;
 293 }
 294
 295 const Http::Environment &WebApplication::env() const
 296 {
 297     return m_env;
 298 }
 299
 300 void WebApplication::setUsername(const QString &username)
 301 {
 302     m_authController->setUsername(username);
 303 }
 304
 305 void WebApplication::setPasswordHash(const QByteArray &passwordHash)
 306 {
 307     m_authController->setPasswordHash(passwordHash);
 308 }
 309
 310 void WebApplication::doProcessRequest()
 311 {
 312     const QRegularExpressionMatch match = m_apiPathPattern.match(request().path);
 313     if (!match.hasMatch())
 314     {
 315         sendWebUIFile();
 316         return;
 317     }
 318
 319     const QString action = match.captured(u"action"_s);
 320     const QString scope = match.captured(u"scope"_s);
 321
 322     // Check public/private scope
 323     if (!session() && !isPublicAPI(scope, action))
 324         throw ForbiddenHTTPError();
 325
 326     // Find matching API
 327     APIController *controller = nullptr;
 328     if (session())
 329         controller = session()->getAPIController(scope);
 330     if (!controller)
 331     {
 332         if (scope == u"auth")
 333             controller = m_authController;
 334         else
 335             throw NotFoundHTTPError();
 336     }
 337
 338     // Filter HTTP methods
 339     const auto allowedMethodIter = m_allowedMethod.find({scope, action});
 340     if (allowedMethodIter == m_allowedMethod.end())
 341     {
 342         // by default allow both GET, POST methods
 343         if ((m_request.method != Http::METHOD_GET) && (m_request.method != Http::METHOD_POST))
 344             throw MethodNotAllowedHTTPError();
 345     }
 346     else
 347     {
 348         if (*allowedMethodIter != m_request.method)
 349             throw MethodNotAllowedHTTPError();
 350     }
 351
 352     DataMap data;
 353     for (const Http::UploadedFile &torrent : request().files)
 354         data[torrent.filename] = torrent.data;
 355
 356     try
 357     {
 358         const APIResult result = controller->run(action, m_params, data);
 359         switch (result.data.userType())
 360         {
 361         case QMetaType::QJsonDocument:
 362             print(result.data.toJsonDocument().toJson(QJsonDocument::Compact), Http::CONTENT_TYPE_JSON);
 363             break;
 364         case QMetaType::QByteArray:
 365             {
 366                 const auto resultData = result.data.toByteArray();
 367                 print(resultData, (!result.mimeType.isEmpty() ? result.mimeType : Http::CONTENT_TYPE_TXT));
 368                 if (!result.filename.isEmpty())
 369                 {
 370                     setHeader({u"Content-Disposition"_s, u"attachment; filename=\"%1\""_s.arg(result.filename)});
 371                 }
 372             }
 373             break;
 374         case QMetaType::QString:
 375         default:
 376             print(result.data.toString(), Http::CONTENT_TYPE_TXT);
 377             break;
 378         }
 379     }
 380     catch (const APIError &error)
 381     {
 382         // re-throw as HTTPError
 383         switch (error.type())
 384         {
 385         case APIErrorType::AccessDenied:
 386             throw ForbiddenHTTPError(error.message());
 387         case APIErrorType::BadData:
 388             throw UnsupportedMediaTypeHTTPError(error.message());
 389         case APIErrorType::BadParams:
 390             throw BadRequestHTTPError(error.message());
 391         case APIErrorType::Conflict:
 392             throw ConflictHTTPError(error.message());
 393         case APIErrorType::NotFound:
 394             throw NotFoundHTTPError(error.message());
 395         default:
 396             Q_ASSERT(false);
 397         }
 398     }
 399 }
 400
 401 void WebApplication::configure()
 402 {
 403     const auto *pref = Preferences::instance();
 404
 405     const bool isAltUIUsed = pref->isAltWebUIEnabled();
 406     const Path rootFolder = (!isAltUIUsed ? Path(WWW_FOLDER) : pref->getWebUIRootFolder());
 407     if ((isAltUIUsed != m_isAltUIUsed) || (rootFolder != m_rootFolder))
 408     {
 409         m_isAltUIUsed = isAltUIUsed;
 410         m_rootFolder = rootFolder;
 411         m_translatedFiles.clear();
 412         if (!m_isAltUIUsed)
 413             LogMsg(tr("Using built-in WebUI."));
 414         else
 415             LogMsg(tr("Using custom WebUI. Location: \"%1\".").arg(m_rootFolder.toString()));
 416     }
 417
 418     const QString newLocale = pref->getLocale();
 419     if (m_currentLocale != newLocale)
 420     {
 421         m_currentLocale = newLocale;
 422         m_translatedFiles.clear();
 423
 424         m_translationFileLoaded = m_translator.load((m_rootFolder / Path(u"translations/webui_"_s) + newLocale).data());
 425         if (m_translationFileLoaded)
 426         {
 427             LogMsg(tr("WebUI translation for selected locale (%1) has been successfully loaded.")
 428                    .arg(newLocale));
 429         }
 430         else
 431         {
 432             LogMsg(tr("Couldn't load WebUI translation for selected locale (%1).").arg(newLocale), Log::WARNING);
 433         }
 434     }
 435
 436     m_isLocalAuthEnabled = pref->isWebUILocalAuthEnabled();
 437     m_isAuthSubnetWhitelistEnabled = pref->isWebUIAuthSubnetWhitelistEnabled();
 438     m_authSubnetWhitelist = pref->getWebUIAuthSubnetWhitelist();
 439     m_sessionTimeout = pref->getWebUISessionTimeout();
 440
 441     m_domainList = pref->getServerDomains().split(u';', Qt::SkipEmptyParts);
 442     std::for_each(m_domainList.begin(), m_domainList.end(), [](QString &entry) { entry = entry.trimmed(); });
 443
 444     m_isCSRFProtectionEnabled = pref->isWebUICSRFProtectionEnabled();
 445     m_isSecureCookieEnabled = pref->isWebUISecureCookieEnabled();
 446     m_isHostHeaderValidationEnabled = pref->isWebUIHostHeaderValidationEnabled();
 447     m_isHttpsEnabled = pref->isWebUIHttpsEnabled();
 448
 449     m_prebuiltHeaders.clear();
 450     m_prebuiltHeaders.push_back({Http::HEADER_X_XSS_PROTECTION, u"1; mode=block"_s});
 451     m_prebuiltHeaders.push_back({Http::HEADER_X_CONTENT_TYPE_OPTIONS, u"nosniff"_s});
 452
 453     if (!m_isAltUIUsed)
 454     {
 455         m_prebuiltHeaders.push_back({Http::HEADER_CROSS_ORIGIN_OPENER_POLICY, u"same-origin"_s});
 456         m_prebuiltHeaders.push_back({Http::HEADER_REFERRER_POLICY, u"same-origin"_s});
 457     }
 458
 459     const bool isClickjackingProtectionEnabled = pref->isWebUIClickjackingProtectionEnabled();
 460     if (isClickjackingProtectionEnabled)
 461         m_prebuiltHeaders.push_back({Http::HEADER_X_FRAME_OPTIONS, u"SAMEORIGIN"_s});
 462
 463     const QString contentSecurityPolicy =
 464         (m_isAltUIUsed
 465             ? QString()
 466             : u"default-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; script-src 'self' 'unsafe-inline'; object-src 'none'; form-action 'self';"_s)
 467         + (isClickjackingProtectionEnabled ? u" frame-ancestors 'self';"_s : QString())
 468         + (m_isHttpsEnabled ? u" upgrade-insecure-requests;"_s : QString());
 469     if (!contentSecurityPolicy.isEmpty())
 470         m_prebuiltHeaders.push_back({Http::HEADER_CONTENT_SECURITY_POLICY, contentSecurityPolicy});
 471
 472     if (pref->isWebUICustomHTTPHeadersEnabled())
 473     {
 474         const QString customHeaders = pref->getWebUICustomHTTPHeaders();
 475         const QList<QStringView> customHeaderLines = QStringView(customHeaders).trimmed().split(u'\n', Qt::SkipEmptyParts);
 476
 477         for (const QStringView line : customHeaderLines)
 478         {
 479             const int idx = line.indexOf(u':');
 480             if (idx < 0)
 481             {
 482                 // require separator `:` to be present even if `value` field can be empty
 483                 LogMsg(tr("Missing ':' separator in WebUI custom HTTP header: \"%1\"").arg(line.toString()), Log::WARNING);
 484                 continue;
 485             }
 486
 487             const QString header = line.left(idx).trimmed().toString();
 488             const QString value = line.mid(idx + 1).trimmed().toString();
 489             m_prebuiltHeaders.push_back({header, value});
 490         }
 491     }
 492
 493     m_isReverseProxySupportEnabled = pref->isWebUIReverseProxySupportEnabled();
 494     if (m_isReverseProxySupportEnabled)
 495     {
 496         const QStringList proxyList = pref->getWebUITrustedReverseProxiesList().split(u';', Qt::SkipEmptyParts);
 497
 498         m_trustedReverseProxyList.clear();
 499         m_trustedReverseProxyList.reserve(proxyList.size());
 500
 501         for (QString proxy : proxyList)
 502         {
 503             if (!proxy.contains(u'/'))
 504             {
 505                 const QAbstractSocket::NetworkLayerProtocol protocol = QHostAddress(proxy).protocol();
 506                 if (protocol == QAbstractSocket::IPv4Protocol)
 507                 {
 508                     proxy.append(u"/32");
 509                 }
 510                 else if (protocol == QAbstractSocket::IPv6Protocol)
 511                 {
 512                     proxy.append(u"/128");
 513                 }
 514             }
 515
 516             const std::optional<Utils::Net::Subnet> subnet = Utils::Net::parseSubnet(proxy);
 517             if (subnet)
 518                 m_trustedReverseProxyList.push_back(subnet.value());
 519         }
 520
 521         if (m_trustedReverseProxyList.isEmpty())
 522             m_isReverseProxySupportEnabled = false;
 523     }
 524 }
 525
 526 void WebApplication::declarePublicAPI(const QString &apiPath)
 527 {
 528     m_publicAPIs << apiPath;
 529 }
 530
 531 void WebApplication::sendFile(const Path &path)
 532 {
 533     const QDateTime lastModified = Utils::Fs::lastModified(path);
 534
 535     // find translated file in cache
 536     if (!m_isAltUIUsed)
 537     {
 538         if (const auto it = m_translatedFiles.constFind(path);
 539             (it != m_translatedFiles.constEnd()) && (lastModified <= it->lastModified))
 540         {
 541             print(it->data, it->mimeType);
 542             setHeader({Http::HEADER_CACHE_CONTROL, getCachingInterval(it->mimeType)});
 543             return;
 544         }
 545     }
 546
 547     const auto readResult = Utils::IO::readFile(path, MAX_ALLOWED_FILESIZE);
 548     if (!readResult)
 549     {
 550         const QString message = tr("Web server error. %1").arg(readResult.error().message);
 551
 552         switch (readResult.error().status)
 553         {
 554         case Utils::IO::ReadError::NotExist:
 555             qDebug("%s", qUtf8Printable(message));
 556             // don't write log messages here to avoid exhausting the disk space
 557             throw NotFoundHTTPError();
 558
 559         case Utils::IO::ReadError::ExceedSize:
 560             qWarning("%s", qUtf8Printable(message));
 561             LogMsg(message, Log::WARNING);
 562             throw InternalServerErrorHTTPError(readResult.error().message);
 563
 564         case Utils::IO::ReadError::Failed:
 565         case Utils::IO::ReadError::SizeMismatch:
 566             LogMsg(message, Log::WARNING);
 567             throw InternalServerErrorHTTPError(readResult.error().message);
 568         }
 569
 570         throw InternalServerErrorHTTPError(tr("Web server error. Unknown error."));
 571     }
 572
 573     QByteArray data = readResult.value();
 574     const QMimeType mimeType = QMimeDatabase().mimeTypeForFileNameAndData(path.data(), data);
 575     const bool isTranslatable = !m_isAltUIUsed && mimeType.inherits(u"text/plain"_s);
 576
 577     if (isTranslatable)
 578     {
 579         auto dataStr = QString::fromUtf8(data);
 580         // Translate the file
 581         translateDocument(dataStr);
 582
 583         // Add the language options
 584         if (path == (m_rootFolder / Path(PRIVATE_FOLDER) / Path(u"views/preferences.html"_s)))
 585             dataStr.replace(u"${LANGUAGE_OPTIONS}"_s, createLanguagesOptionsHtml());
 586
 587         data = dataStr.toUtf8();
 588         m_translatedFiles[path] = {data, mimeType.name(), lastModified}; // caching translated file
 589     }
 590
 591     print(data, mimeType.name());
 592     setHeader({Http::HEADER_CACHE_CONTROL, getCachingInterval(mimeType.name())});
 593 }
 594
 595 Http::Response WebApplication::processRequest(const Http::Request &request, const Http::Environment &env)
 596 {
 597     m_currentSession = nullptr;
 598     m_request = request;
 599     m_env = env;
 600     m_params.clear();
 601
 602     if (m_request.method == Http::METHOD_GET)
 603     {
 604         for (auto iter = m_request.query.cbegin(); iter != m_request.query.cend(); ++iter)
 605             m_params[iter.key()] = QString::fromUtf8(iter.value());
 606     }
 607     else
 608     {
 609         m_params = m_request.posts;
 610     }
 611
 612     // clear response
 613     clear();
 614
 615     try
 616     {
 617         // block suspicious requests
 618         if ((m_isCSRFProtectionEnabled && isCrossSiteRequest(m_request))
 619             || (m_isHostHeaderValidationEnabled && !validateHostHeader(m_domainList)))
 620         {
 621             throw UnauthorizedHTTPError();
 622         }
 623
 624         // reverse proxy resolve client address
 625         m_clientAddress = resolveClientAddress();
 626
 627         sessionInitialize();
 628         doProcessRequest();
 629     }
 630     catch (const HTTPError &error)
 631     {
 632         status(error.statusCode(), error.statusText());
 633         print((!error.message().isEmpty() ? error.message() : error.statusText()), Http::CONTENT_TYPE_TXT);
 634     }
 635
 636     for (const Http::Header &prebuiltHeader : asConst(m_prebuiltHeaders))
 637         setHeader(prebuiltHeader);
 638
 639     return response();
 640 }
 641
 642 QString WebApplication::clientId() const
 643 {
 644     return m_clientAddress.toString();
 645 }
 646
 647 void WebApplication::sessionInitialize()
 648 {
 649     Q_ASSERT(!m_currentSession);
 650
 651     const QString sessionId {parseCookie(m_request.headers.value(u"cookie"_s)).value(m_sessionCookieName)};
 652
 653     // TODO: Additional session check
 654
 655     if (!sessionId.isEmpty())
 656     {
 657         m_currentSession = m_sessions.value(sessionId);
 658         if (m_currentSession)
 659         {
 660             if (m_currentSession->hasExpired(m_sessionTimeout))
 661             {
 662                 // session is outdated - removing it
 663                 delete m_sessions.take(sessionId);
 664                 m_currentSession = nullptr;
 665             }
 666             else
 667             {
 668                 m_currentSession->updateTimestamp();
 669             }
 670         }
 671         else
 672         {
 673             qDebug() << Q_FUNC_INFO << "session does not exist!";
 674         }
 675     }
 676
 677     if (!m_currentSession && !isAuthNeeded())
 678         sessionStart();
 679 }
 680
 681 QString WebApplication::generateSid() const
 682 {
 683     QString sid;
 684
 685     do
 686     {
 687         const quint32 tmp[] =
 688         {Utils::Random::rand(), Utils::Random::rand(), Utils::Random::rand()
 689                 , Utils::Random::rand(), Utils::Random::rand(), Utils::Random::rand()};
 690         sid = QString::fromLatin1(QByteArray::fromRawData(reinterpret_cast<const char *>(tmp), sizeof(tmp)).toBase64());
 691     }
 692     while (m_sessions.contains(sid));
 693
 694     return sid;
 695 }
 696
 697 bool WebApplication::isAuthNeeded()
 698 {
 699     if (!m_isLocalAuthEnabled && Utils::Net::isLoopbackAddress(m_clientAddress))
 700         return false;
 701     if (m_isAuthSubnetWhitelistEnabled && Utils::Net::isIPInSubnets(m_clientAddress, m_authSubnetWhitelist))
 702         return false;
 703     return true;
 704 }
 705
 706 bool WebApplication::isPublicAPI(const QString &scope, const QString &action) const
 707 {
 708     return m_publicAPIs.contains(u"%1/%2"_s.arg(scope, action));
 709 }
 710
 711 void WebApplication::sessionStart()
 712 {
 713     Q_ASSERT(!m_currentSession);
 714
 715     // remove outdated sessions
 716     Algorithm::removeIf(m_sessions, [this](const QString &, const WebSession *session)
 717     {
 718         if (session->hasExpired(m_sessionTimeout))
 719         {
 720             delete session;
 721             return true;
 722         }
 723
 724         return false;
 725     });
 726
 727     m_currentSession = new WebSession(generateSid(), app());
 728     m_sessions[m_currentSession->id()] = m_currentSession;
 729
 730     m_currentSession->registerAPIController(u"app"_s, new AppController(app(), this));
 731     m_currentSession->registerAPIController(u"log"_s, new LogController(app(), this));
 732     m_currentSession->registerAPIController(u"torrentcreator"_s, new TorrentCreatorController(m_torrentCreationManager, app(), this));
 733     m_currentSession->registerAPIController(u"rss"_s, new RSSController(app(), this));
 734     m_currentSession->registerAPIController(u"search"_s, new SearchController(app(), this));
 735     m_currentSession->registerAPIController(u"torrents"_s, new TorrentsController(app(), this));
 736     m_currentSession->registerAPIController(u"transfer"_s, new TransferController(app(), this));
 737
 738     auto *syncController = new SyncController(app(), this);
 739     syncController->updateFreeDiskSpace(m_freeDiskSpaceChecker->lastResult());
 740     connect(m_freeDiskSpaceChecker, &FreeDiskSpaceChecker::checked, syncController, &SyncController::updateFreeDiskSpace);
 741     m_currentSession->registerAPIController(u"sync"_s, syncController);
 742
 743     QNetworkCookie cookie {m_sessionCookieName.toLatin1(), m_currentSession->id().toUtf8()};
 744     cookie.setHttpOnly(true);
 745     cookie.setSecure(m_isSecureCookieEnabled && m_isHttpsEnabled);
 746     cookie.setPath(u"/"_s);
 747     QByteArray cookieRawForm = cookie.toRawForm();
 748     if (m_isCSRFProtectionEnabled)
 749         cookieRawForm.append("; SameSite=Strict");
 750     else if (cookie.isSecure())
 751         cookieRawForm.append("; SameSite=None");
 752     setHeader({Http::HEADER_SET_COOKIE, QString::fromLatin1(cookieRawForm)});
 753 }
 754
 755 void WebApplication::sessionEnd()
 756 {
 757     Q_ASSERT(m_currentSession);
 758
 759     QNetworkCookie cookie {m_sessionCookieName.toLatin1()};
 760     cookie.setPath(u"/"_s);
 761     cookie.setExpirationDate(QDateTime::currentDateTime().addDays(-1));
 762
 763     delete m_sessions.take(m_currentSession->id());
 764     m_currentSession = nullptr;
 765
 766     setHeader({Http::HEADER_SET_COOKIE, QString::fromLatin1(cookie.toRawForm())});
 767 }
 768
 769 bool WebApplication::isCrossSiteRequest(const Http::Request &request) const
 770 {
 771     // https://www.owasp.org/index.php/Cross-Site_Request_Forgery_(CSRF)_Prevention_Cheat_Sheet#Verifying_Same_Origin_with_Standard_Headers
 772
 773     const auto isSameOrigin = [](const QUrl &left, const QUrl &right) -> bool
 774     {
 775         // [rfc6454] 5. Comparing Origins
 776         return ((left.port() == right.port())
 777                 // && (left.scheme() == right.scheme())  // not present in this context
 778                 && (left.host() == right.host()));
 779     };
 780
 781     const QString targetOrigin = request.headers.value(Http::HEADER_X_FORWARDED_HOST, request.headers.value(Http::HEADER_HOST));
 782     const QString originValue = request.headers.value(Http::HEADER_ORIGIN);
 783     const QString refererValue = request.headers.value(Http::HEADER_REFERER);
 784
 785     if (originValue.isEmpty() && refererValue.isEmpty())
 786     {
 787         // owasp.org recommends to block this request, but doing so will inevitably lead Web API users to spoof headers
 788         // so lets be permissive here
 789         return false;
 790     }
 791
 792     // sent with CORS requests, as well as with POST requests
 793     if (!originValue.isEmpty())
 794     {
 795         const bool isInvalid = !isSameOrigin(urlFromHostHeader(targetOrigin), originValue);
 796         if (isInvalid)
 797         {
 798             LogMsg(tr("WebUI: Origin header & Target origin mismatch! Source IP: '%1'. Origin header: '%2'. Target origin: '%3'")
 799                    .arg(m_env.clientAddress.toString(), originValue, targetOrigin)
 800                    , Log::WARNING);
 801         }
 802         return isInvalid;
 803     }
 804
 805     if (!refererValue.isEmpty())
 806     {
 807         const bool isInvalid = !isSameOrigin(urlFromHostHeader(targetOrigin), refererValue);
 808         if (isInvalid)
 809         {
 810             LogMsg(tr("WebUI: Referer header & Target origin mismatch! Source IP: '%1'. Referer header: '%2'. Target origin: '%3'")
 811                    .arg(m_env.clientAddress.toString(), refererValue, targetOrigin)
 812                    , Log::WARNING);
 813         }
 814         return isInvalid;
 815     }
 816
 817     return true;
 818 }
 819
 820 bool WebApplication::validateHostHeader(const QStringList &domains) const
 821 {
 822     const QUrl hostHeader = urlFromHostHeader(m_request.headers[Http::HEADER_HOST]);
 823     const QString requestHost = hostHeader.host();
 824
 825     // (if present) try matching host header's port with local port
 826     const int requestPort = hostHeader.port();
 827     if ((requestPort != -1) && (m_env.localPort != requestPort))
 828     {
 829         LogMsg(tr("WebUI: Invalid Host header, port mismatch. Request source IP: '%1'. Server port: '%2'. Received Host header: '%3'")
 830                .arg(m_env.clientAddress.toString()).arg(m_env.localPort)
 831                .arg(m_request.headers[Http::HEADER_HOST])
 832                 , Log::WARNING);
 833         return false;
 834     }
 835
 836     // try matching host header with local address
 837     const bool sameAddr = m_env.localAddress.isEqual(QHostAddress(requestHost));
 838
 839     if (sameAddr)
 840         return true;
 841
 842     // try matching host header with domain list
 843     for (const auto &domain : domains)
 844     {
 845         const QRegularExpression domainRegex {Utils::String::wildcardToRegexPattern(domain), QRegularExpression::CaseInsensitiveOption};
 846         if (requestHost.contains(domainRegex))
 847             return true;
 848     }
 849
 850     LogMsg(tr("WebUI: Invalid Host header. Request source IP: '%1'. Received Host header: '%2'")
 851            .arg(m_env.clientAddress.toString(), m_request.headers[Http::HEADER_HOST])
 852             , Log::WARNING);
 853     return false;
 854 }
 855
 856 QHostAddress WebApplication::resolveClientAddress() const
 857 {
 858     if (!m_isReverseProxySupportEnabled)
 859         return m_env.clientAddress;
 860
 861     // Only reverse proxy can overwrite client address
 862     if (!Utils::Net::isIPInSubnets(m_env.clientAddress, m_trustedReverseProxyList))
 863         return m_env.clientAddress;
 864
 865     const QString forwardedFor = m_request.headers.value(Http::HEADER_X_FORWARDED_FOR);
 866
 867     if (!forwardedFor.isEmpty())
 868     {
 869         // client address is the 1st global IP in X-Forwarded-For or, if none available, the 1st IP in the list
 870         const QStringList remoteIpList = forwardedFor.split(u',', Qt::SkipEmptyParts);
 871
 872         if (!remoteIpList.isEmpty())
 873         {
 874             QHostAddress clientAddress;
 875
 876             for (const QString &remoteIp : remoteIpList)
 877             {
 878                 if (clientAddress.setAddress(remoteIp) && clientAddress.isGlobal())
 879                     return clientAddress;
 880             }
 881
 882             if (clientAddress.setAddress(remoteIpList[0]))
 883                 return clientAddress;
 884         }
 885     }
 886
 887     return m_env.clientAddress;
 888 }
 889
 890 // WebSession
 891
 892 WebSession::WebSession(const QString &sid, IApplication *app)
 893     : ApplicationComponent(app)
 894     , m_sid {sid}
 895 {
 896     updateTimestamp();
 897 }
 898
 899 QString WebSession::id() const
 900 {
 901     return m_sid;
 902 }
 903
 904 bool WebSession::hasExpired(const qint64 seconds) const
 905 {
 906     if (seconds <= 0)
 907         return false;
 908     return m_timer.hasExpired(seconds * 1000);
 909 }
 910
 911 void WebSession::updateTimestamp()
 912 {
 913     m_timer.start();
 914 }
 915
 916 void WebSession::registerAPIController(const QString &scope, APIController *controller)
 917 {
 918     Q_ASSERT(controller);
 919     m_apiControllers[scope] = controller;
 920 }
 921
 922 APIController *WebSession::getAPIController(const QString &scope) const
 923 {
 924     return m_apiControllers.value(scope);
 925 }