src/webui/webapplication.cpp

   1 /*
   2  * Bittorrent Client using Qt and libtorrent.
   3  * Copyright (C) 2014, 2022-2023  Vladimir Golovnev <glassez@yandex.ru>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18  *
  19  * In addition, as a special exception, the copyright holders give permission to
  20  * link this program with the OpenSSL project's "OpenSSL" library (or with
  21  * modified versions of it that use the same license as the "OpenSSL" library),
  22  * and distribute the linked executables. You must obey the GNU General Public
  23  * License in all respects for all of the code used other than "OpenSSL".  If you
  24  * modify file(s), you may extend this exception to your version of the file(s),
  25  * but you are not obligated to do so. If you do not wish to do so, delete this
  26  * exception statement from your version.
  27  */
  28
  29 #include "webapplication.h"
  30
  31 #include <algorithm>
  32 #include <chrono>
  33
  34 #include <QDateTime>
  35 #include <QDebug>
  36 #include <QDir>
  37 #include <QFileInfo>
  38 #include <QJsonDocument>
  39 #include <QMetaObject>
  40 #include <QMimeDatabase>
  41 #include <QMimeType>
  42 #include <QNetworkCookie>
  43 #include <QRegularExpression>
  44 #include <QThread>
  45 #include <QTimer>
  46 #include <QUrl>
  47
  48 #include "base/algorithm.h"
  49 #include "base/http/httperror.h"
  50 #include "base/logger.h"
  51 #include "base/preferences.h"
  52 #include "base/types.h"
  53 #include "base/utils/fs.h"
  54 #include "base/utils/io.h"
  55 #include "base/utils/misc.h"
  56 #include "base/utils/random.h"
  57 #include "base/utils/string.h"
  58 #include "api/apierror.h"
  59 #include "api/appcontroller.h"
  60 #include "api/authcontroller.h"
  61 #include "api/logcontroller.h"
  62 #include "api/rsscontroller.h"
  63 #include "api/searchcontroller.h"
  64 #include "api/synccontroller.h"
  65 #include "api/torrentscontroller.h"
  66 #include "api/transfercontroller.h"
  67 #include "freediskspacechecker.h"
  68
  69 const int MAX_ALLOWED_FILESIZE = 10 * 1024 * 1024;
  70 const QString DEFAULT_SESSION_COOKIE_NAME = u"SID"_s;
  71
  72 const QString WWW_FOLDER = u":/www"_s;
  73 const QString PUBLIC_FOLDER = u"/public"_s;
  74 const QString PRIVATE_FOLDER = u"/private"_s;
  75
  76 using namespace std::chrono_literals;
  77
  78 const std::chrono::seconds FREEDISKSPACE_CHECK_TIMEOUT = 30s;
  79
  80 namespace
  81 {
  82     QStringMap parseCookie(const QStringView cookieStr)
  83     {
  84         // [rfc6265] 4.2.1. Syntax
  85         QStringMap ret;
  86         const QList<QStringView> cookies = cookieStr.split(u';', Qt::SkipEmptyParts);
  87
  88         for (const auto &cookie : cookies)
  89         {
  90             const int idx = cookie.indexOf(u'=');
  91             if (idx < 0)
  92                 continue;
  93
  94             const QString name = cookie.left(idx).trimmed().toString();
  95             const QString value = Utils::String::unquote(cookie.mid(idx + 1).trimmed()).toString();
  96             ret.insert(name, value);
  97         }
  98         return ret;
  99     }
 100
 101     QUrl urlFromHostHeader(const QString &hostHeader)
 102     {
 103         if (!hostHeader.contains(u"://"))
 104             return {u"http://"_s + hostHeader};
 105         return hostHeader;
 106     }
 107
 108     QString getCachingInterval(QString contentType)
 109     {
 110         contentType = contentType.toLower();
 111
 112         if (contentType.startsWith(u"image/"))
 113             return u"private, max-age=604800"_s;  // 1 week
 114
 115         if ((contentType == Http::CONTENT_TYPE_CSS)
 116             || (contentType == Http::CONTENT_TYPE_JS))
 117             {
 118             // short interval in case of program update
 119             return u"private, max-age=43200"_s;  // 12 hrs
 120         }
 121
 122         return u"no-store"_s;
 123     }
 124
 125     QString createLanguagesOptionsHtml()
 126     {
 127         // List language files
 128         const QDir langDir {u":/www/translations"_s};
 129         const QStringList langFiles = langDir.entryList(QStringList(u"webui_*.qm"_s), QDir::Files);
 130         QStringList languages;
 131         for (const QString &langFile : langFiles)
 132         {
 133             const QString localeStr = langFile.section(u"_"_s, 1, -1).section(u"."_s, 0, 0); // remove "webui_" and ".qm"
 134             languages << u"<option value=\"%1\">%2</option>"_s.arg(localeStr, Utils::Misc::languageToLocalizedString(localeStr));
 135             qDebug() << "Supported locale:" << localeStr;
 136         }
 137
 138         return languages.join(u'\n');
 139     }
 140
 141     bool isValidCookieName(const QString &cookieName)
 142     {
 143         if (cookieName.isEmpty() || (cookieName.size() > 128))
 144             return false;
 145
 146         const QRegularExpression invalidNameRegex {u"[^a-zA-Z0-9_\\-]"_s};
 147         if (invalidNameRegex.match(cookieName).hasMatch())
 148             return false;
 149
 150         return true;
 151     }
 152 }
 153
 154 WebApplication::WebApplication(IApplication *app, QObject *parent)
 155     : ApplicationComponent(app, parent)
 156     , m_cacheID {QString::number(Utils::Random::rand(), 36)}
 157     , m_authController {new AuthController(this, app, this)}
 158     , m_workerThread {new QThread}
 159     , m_freeDiskSpaceChecker {new FreeDiskSpaceChecker}
 160     , m_freeDiskSpaceCheckingTimer {new QTimer(this)}
 161 {
 162     declarePublicAPI(u"auth/login"_s);
 163
 164     configure();
 165     connect(Preferences::instance(), &Preferences::changed, this, &WebApplication::configure);
 166
 167     m_sessionCookieName = Preferences::instance()->getWebAPISessionCookieName();
 168     if (!isValidCookieName(m_sessionCookieName))
 169     {
 170         if (!m_sessionCookieName.isEmpty())
 171         {
 172             LogMsg(tr("Unacceptable session cookie name is specified: '%1'. Default one is used.")
 173                    .arg(m_sessionCookieName), Log::WARNING);
 174         }
 175         m_sessionCookieName = DEFAULT_SESSION_COOKIE_NAME;
 176     }
 177
 178     m_freeDiskSpaceChecker->moveToThread(m_workerThread.get());
 179     connect(m_workerThread.get(), &QThread::finished, m_freeDiskSpaceChecker, &QObject::deleteLater);
 180     m_workerThread->start();
 181
 182     m_freeDiskSpaceCheckingTimer->setInterval(FREEDISKSPACE_CHECK_TIMEOUT);
 183     m_freeDiskSpaceCheckingTimer->setSingleShot(true);
 184     connect(m_freeDiskSpaceCheckingTimer, &QTimer::timeout, m_freeDiskSpaceChecker, &FreeDiskSpaceChecker::check);
 185     connect(m_freeDiskSpaceChecker, &FreeDiskSpaceChecker::checked, m_freeDiskSpaceCheckingTimer, qOverload<>(&QTimer::start));
 186     QMetaObject::invokeMethod(m_freeDiskSpaceChecker, &FreeDiskSpaceChecker::check);
 187 }
 188
 189 WebApplication::~WebApplication()
 190 {
 191     // cleanup sessions data
 192     qDeleteAll(m_sessions);
 193 }
 194
 195 void WebApplication::sendWebUIFile()
 196 {
 197     if (request().path.contains(u'\\'))
 198         throw BadRequestHTTPError();
 199
 200     if (const QList<QStringView> pathItems = QStringView(request().path).split(u'/', Qt::SkipEmptyParts)
 201             ; pathItems.contains(u".") || pathItems.contains(u".."))
 202     {
 203         throw BadRequestHTTPError();
 204     }
 205
 206     const QString path = (request().path != u"/")
 207         ? request().path
 208         : u"/index.html"_s;
 209
 210     Path localPath = m_rootFolder
 211                 / Path(session() ? PRIVATE_FOLDER : PUBLIC_FOLDER)
 212                 / Path(path);
 213     if (!localPath.exists() && session())
 214     {
 215         // try to send public file if there is no private one
 216         localPath = m_rootFolder / Path(PUBLIC_FOLDER) / Path(path);
 217     }
 218
 219     if (m_isAltUIUsed)
 220     {
 221         if (!Utils::Fs::isRegularFile(localPath))
 222             throw InternalServerErrorHTTPError(tr("Unacceptable file type, only regular file is allowed."));
 223
 224         const QString rootFolder = m_rootFolder.data();
 225
 226         QFileInfo fileInfo {localPath.parentPath().data()};
 227         while (fileInfo.path() != rootFolder)
 228         {
 229             if (fileInfo.isSymLink())
 230                 throw InternalServerErrorHTTPError(tr("Symlinks inside alternative UI folder are forbidden."));
 231
 232             fileInfo.setFile(fileInfo.path());
 233         }
 234     }
 235
 236     sendFile(localPath);
 237 }
 238
 239 void WebApplication::translateDocument(QString &data) const
 240 {
 241     const QRegularExpression regex(u"QBT_TR\\((([^\\)]|\\)(?!QBT_TR))+)\\)QBT_TR\\[CONTEXT=([a-zA-Z_][a-zA-Z0-9_]*)\\]"_s);
 242
 243     int i = 0;
 244     bool found = true;
 245     while (i < data.size() && found)
 246     {
 247         QRegularExpressionMatch regexMatch;
 248         i = data.indexOf(regex, i, &regexMatch);
 249         if (i >= 0)
 250         {
 251             const QString sourceText = regexMatch.captured(1);
 252             const QString context = regexMatch.captured(3);
 253
 254             const QString loadedText = m_translationFileLoaded
 255                 ? m_translator.translate(context.toUtf8().constData(), sourceText.toUtf8().constData())
 256                 : QString();
 257             // `loadedText` is empty when translation is not provided
 258             // it should fallback to `sourceText`
 259             QString translation = loadedText.isEmpty() ? sourceText : loadedText;
 260
 261             // Use HTML code for quotes to prevent issues with JS
 262             translation.replace(u'\'', u"&#39;"_s);
 263             translation.replace(u'\"', u"&#34;"_s);
 264
 265             data.replace(i, regexMatch.capturedLength(), translation);
 266             i += translation.length();
 267         }
 268         else
 269         {
 270             found = false; // no more translatable strings
 271         }
 272
 273         data.replace(u"${LANG}"_s, m_currentLocale.left(2));
 274         data.replace(u"${CACHEID}"_s, m_cacheID);
 275     }
 276 }
 277
 278 WebSession *WebApplication::session()
 279 {
 280     return m_currentSession;
 281 }
 282
 283 const Http::Request &WebApplication::request() const
 284 {
 285     return m_request;
 286 }
 287
 288 const Http::Environment &WebApplication::env() const
 289 {
 290     return m_env;
 291 }
 292
 293 void WebApplication::setUsername(const QString &username)
 294 {
 295     m_authController->setUsername(username);
 296 }
 297
 298 void WebApplication::setPasswordHash(const QByteArray &passwordHash)
 299 {
 300     m_authController->setPasswordHash(passwordHash);
 301 }
 302
 303 void WebApplication::doProcessRequest()
 304 {
 305     const QRegularExpressionMatch match = m_apiPathPattern.match(request().path);
 306     if (!match.hasMatch())
 307     {
 308         sendWebUIFile();
 309         return;
 310     }
 311
 312     const QString action = match.captured(u"action"_s);
 313     const QString scope = match.captured(u"scope"_s);
 314
 315     // Check public/private scope
 316     if (!session() && !isPublicAPI(scope, action))
 317         throw ForbiddenHTTPError();
 318
 319     // Find matching API
 320     APIController *controller = nullptr;
 321     if (session())
 322         controller = session()->getAPIController(scope);
 323     if (!controller)
 324     {
 325         if (scope == u"auth")
 326             controller = m_authController;
 327         else
 328             throw NotFoundHTTPError();
 329     }
 330
 331     // Filter HTTP methods
 332     const auto allowedMethodIter = m_allowedMethod.find({scope, action});
 333     if (allowedMethodIter == m_allowedMethod.end())
 334     {
 335         // by default allow both GET, POST methods
 336         if ((m_request.method != Http::METHOD_GET) && (m_request.method != Http::METHOD_POST))
 337             throw MethodNotAllowedHTTPError();
 338     }
 339     else
 340     {
 341         if (*allowedMethodIter != m_request.method)
 342             throw MethodNotAllowedHTTPError();
 343     }
 344
 345     DataMap data;
 346     for (const Http::UploadedFile &torrent : request().files)
 347         data[torrent.filename] = torrent.data;
 348
 349     try
 350     {
 351         const QVariant result = controller->run(action, m_params, data);
 352         switch (result.userType())
 353         {
 354         case QMetaType::QJsonDocument:
 355             print(result.toJsonDocument().toJson(QJsonDocument::Compact), Http::CONTENT_TYPE_JSON);
 356             break;
 357         case QMetaType::QByteArray:
 358             print(result.toByteArray(), Http::CONTENT_TYPE_TXT);
 359             break;
 360         case QMetaType::QString:
 361         default:
 362             print(result.toString(), Http::CONTENT_TYPE_TXT);
 363             break;
 364         }
 365     }
 366     catch (const APIError &error)
 367     {
 368         // re-throw as HTTPError
 369         switch (error.type())
 370         {
 371         case APIErrorType::AccessDenied:
 372             throw ForbiddenHTTPError(error.message());
 373         case APIErrorType::BadData:
 374             throw UnsupportedMediaTypeHTTPError(error.message());
 375         case APIErrorType::BadParams:
 376             throw BadRequestHTTPError(error.message());
 377         case APIErrorType::Conflict:
 378             throw ConflictHTTPError(error.message());
 379         case APIErrorType::NotFound:
 380             throw NotFoundHTTPError(error.message());
 381         default:
 382             Q_ASSERT(false);
 383         }
 384     }
 385 }
 386
 387 void WebApplication::configure()
 388 {
 389     const auto *pref = Preferences::instance();
 390
 391     const bool isAltUIUsed = pref->isAltWebUIEnabled();
 392     const Path rootFolder = (!isAltUIUsed ? Path(WWW_FOLDER) : pref->getWebUIRootFolder());
 393     if ((isAltUIUsed != m_isAltUIUsed) || (rootFolder != m_rootFolder))
 394     {
 395         m_isAltUIUsed = isAltUIUsed;
 396         m_rootFolder = rootFolder;
 397         m_translatedFiles.clear();
 398         if (!m_isAltUIUsed)
 399             LogMsg(tr("Using built-in WebUI."));
 400         else
 401             LogMsg(tr("Using custom WebUI. Location: \"%1\".").arg(m_rootFolder.toString()));
 402     }
 403
 404     const QString newLocale = pref->getLocale();
 405     if (m_currentLocale != newLocale)
 406     {
 407         m_currentLocale = newLocale;
 408         m_translatedFiles.clear();
 409
 410         m_translationFileLoaded = m_translator.load((m_rootFolder / Path(u"translations/webui_"_s) + newLocale).data());
 411         if (m_translationFileLoaded)
 412         {
 413             LogMsg(tr("WebUI translation for selected locale (%1) has been successfully loaded.")
 414                    .arg(newLocale));
 415         }
 416         else
 417         {
 418             LogMsg(tr("Couldn't load WebUI translation for selected locale (%1).").arg(newLocale), Log::WARNING);
 419         }
 420     }
 421
 422     m_isLocalAuthEnabled = pref->isWebUILocalAuthEnabled();
 423     m_isAuthSubnetWhitelistEnabled = pref->isWebUIAuthSubnetWhitelistEnabled();
 424     m_authSubnetWhitelist = pref->getWebUIAuthSubnetWhitelist();
 425     m_sessionTimeout = pref->getWebUISessionTimeout();
 426
 427     m_domainList = pref->getServerDomains().split(u';', Qt::SkipEmptyParts);
 428     std::for_each(m_domainList.begin(), m_domainList.end(), [](QString &entry) { entry = entry.trimmed(); });
 429
 430     m_isCSRFProtectionEnabled = pref->isWebUICSRFProtectionEnabled();
 431     m_isSecureCookieEnabled = pref->isWebUISecureCookieEnabled();
 432     m_isHostHeaderValidationEnabled = pref->isWebUIHostHeaderValidationEnabled();
 433     m_isHttpsEnabled = pref->isWebUIHttpsEnabled();
 434
 435     m_prebuiltHeaders.clear();
 436     m_prebuiltHeaders.push_back({Http::HEADER_X_XSS_PROTECTION, u"1; mode=block"_s});
 437     m_prebuiltHeaders.push_back({Http::HEADER_X_CONTENT_TYPE_OPTIONS, u"nosniff"_s});
 438
 439     if (!m_isAltUIUsed)
 440     {
 441         m_prebuiltHeaders.push_back({Http::HEADER_CROSS_ORIGIN_OPENER_POLICY, u"same-origin"_s});
 442         m_prebuiltHeaders.push_back({Http::HEADER_REFERRER_POLICY, u"same-origin"_s});
 443     }
 444
 445     const bool isClickjackingProtectionEnabled = pref->isWebUIClickjackingProtectionEnabled();
 446     if (isClickjackingProtectionEnabled)
 447         m_prebuiltHeaders.push_back({Http::HEADER_X_FRAME_OPTIONS, u"SAMEORIGIN"_s});
 448
 449     const QString contentSecurityPolicy =
 450         (m_isAltUIUsed
 451             ? QString()
 452             : 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)
 453         + (isClickjackingProtectionEnabled ? u" frame-ancestors 'self';"_s : QString())
 454         + (m_isHttpsEnabled ? u" upgrade-insecure-requests;"_s : QString());
 455     if (!contentSecurityPolicy.isEmpty())
 456         m_prebuiltHeaders.push_back({Http::HEADER_CONTENT_SECURITY_POLICY, contentSecurityPolicy});
 457
 458     if (pref->isWebUICustomHTTPHeadersEnabled())
 459     {
 460         const QString customHeaders = pref->getWebUICustomHTTPHeaders();
 461         const QList<QStringView> customHeaderLines = QStringView(customHeaders).trimmed().split(u'\n', Qt::SkipEmptyParts);
 462
 463         for (const QStringView line : customHeaderLines)
 464         {
 465             const int idx = line.indexOf(u':');
 466             if (idx < 0)
 467             {
 468                 // require separator `:` to be present even if `value` field can be empty
 469                 LogMsg(tr("Missing ':' separator in WebUI custom HTTP header: \"%1\"").arg(line.toString()), Log::WARNING);
 470                 continue;
 471             }
 472
 473             const QString header = line.left(idx).trimmed().toString();
 474             const QString value = line.mid(idx + 1).trimmed().toString();
 475             m_prebuiltHeaders.push_back({header, value});
 476         }
 477     }
 478
 479     m_isReverseProxySupportEnabled = pref->isWebUIReverseProxySupportEnabled();
 480     if (m_isReverseProxySupportEnabled)
 481     {
 482         const QStringList proxyList = pref->getWebUITrustedReverseProxiesList().split(u';', Qt::SkipEmptyParts);
 483
 484         m_trustedReverseProxyList.clear();
 485         m_trustedReverseProxyList.reserve(proxyList.size());
 486
 487         for (QString proxy : proxyList)
 488         {
 489             if (!proxy.contains(u'/'))
 490             {
 491                 const QAbstractSocket::NetworkLayerProtocol protocol = QHostAddress(proxy).protocol();
 492                 if (protocol == QAbstractSocket::IPv4Protocol)
 493                 {
 494                     proxy.append(u"/32");
 495                 }
 496                 else if (protocol == QAbstractSocket::IPv6Protocol)
 497                 {
 498                     proxy.append(u"/128");
 499                 }
 500             }
 501
 502             const std::optional<Utils::Net::Subnet> subnet = Utils::Net::parseSubnet(proxy);
 503             if (subnet)
 504                 m_trustedReverseProxyList.push_back(subnet.value());
 505         }
 506
 507         if (m_trustedReverseProxyList.isEmpty())
 508             m_isReverseProxySupportEnabled = false;
 509     }
 510 }
 511
 512 void WebApplication::declarePublicAPI(const QString &apiPath)
 513 {
 514     m_publicAPIs << apiPath;
 515 }
 516
 517 void WebApplication::sendFile(const Path &path)
 518 {
 519     const QDateTime lastModified = Utils::Fs::lastModified(path);
 520
 521     // find translated file in cache
 522     if (!m_isAltUIUsed)
 523     {
 524         if (const auto it = m_translatedFiles.constFind(path);
 525             (it != m_translatedFiles.constEnd()) && (lastModified <= it->lastModified))
 526         {
 527             print(it->data, it->mimeType);
 528             setHeader({Http::HEADER_CACHE_CONTROL, getCachingInterval(it->mimeType)});
 529             return;
 530         }
 531     }
 532
 533     const auto readResult = Utils::IO::readFile(path, MAX_ALLOWED_FILESIZE);
 534     if (!readResult)
 535     {
 536         const QString message = tr("Web server error. %1").arg(readResult.error().message);
 537
 538         switch (readResult.error().status)
 539         {
 540         case Utils::IO::ReadError::NotExist:
 541             qDebug("%s", qUtf8Printable(message));
 542             // don't write log messages here to avoid exhausting the disk space
 543             throw NotFoundHTTPError();
 544
 545         case Utils::IO::ReadError::ExceedSize:
 546             qWarning("%s", qUtf8Printable(message));
 547             LogMsg(message, Log::WARNING);
 548             throw InternalServerErrorHTTPError(readResult.error().message);
 549
 550         case Utils::IO::ReadError::Failed:
 551         case Utils::IO::ReadError::SizeMismatch:
 552             LogMsg(message, Log::WARNING);
 553             throw InternalServerErrorHTTPError(readResult.error().message);
 554         }
 555
 556         throw InternalServerErrorHTTPError(tr("Web server error. Unknown error."));
 557     }
 558
 559     QByteArray data = readResult.value();
 560     const QMimeType mimeType = QMimeDatabase().mimeTypeForFileNameAndData(path.data(), data);
 561     const bool isTranslatable = !m_isAltUIUsed && mimeType.inherits(u"text/plain"_s);
 562
 563     if (isTranslatable)
 564     {
 565         auto dataStr = QString::fromUtf8(data);
 566         // Translate the file
 567         translateDocument(dataStr);
 568
 569         // Add the language options
 570         if (path == (m_rootFolder / Path(PRIVATE_FOLDER) / Path(u"views/preferences.html"_s)))
 571             dataStr.replace(u"${LANGUAGE_OPTIONS}"_s, createLanguagesOptionsHtml());
 572
 573         data = dataStr.toUtf8();
 574         m_translatedFiles[path] = {data, mimeType.name(), lastModified}; // caching translated file
 575     }
 576
 577     print(data, mimeType.name());
 578     setHeader({Http::HEADER_CACHE_CONTROL, getCachingInterval(mimeType.name())});
 579 }
 580
 581 Http::Response WebApplication::processRequest(const Http::Request &request, const Http::Environment &env)
 582 {
 583     m_currentSession = nullptr;
 584     m_request = request;
 585     m_env = env;
 586     m_params.clear();
 587
 588     if (m_request.method == Http::METHOD_GET)
 589     {
 590         for (auto iter = m_request.query.cbegin(); iter != m_request.query.cend(); ++iter)
 591             m_params[iter.key()] = QString::fromUtf8(iter.value());
 592     }
 593     else
 594     {
 595         m_params = m_request.posts;
 596     }
 597
 598     // clear response
 599     clear();
 600
 601     try
 602     {
 603         // block suspicious requests
 604         if ((m_isCSRFProtectionEnabled && isCrossSiteRequest(m_request))
 605             || (m_isHostHeaderValidationEnabled && !validateHostHeader(m_domainList)))
 606         {
 607             throw UnauthorizedHTTPError();
 608         }
 609
 610         // reverse proxy resolve client address
 611         m_clientAddress = resolveClientAddress();
 612
 613         sessionInitialize();
 614         doProcessRequest();
 615     }
 616     catch (const HTTPError &error)
 617     {
 618         status(error.statusCode(), error.statusText());
 619         print((!error.message().isEmpty() ? error.message() : error.statusText()), Http::CONTENT_TYPE_TXT);
 620     }
 621
 622     for (const Http::Header &prebuiltHeader : asConst(m_prebuiltHeaders))
 623         setHeader(prebuiltHeader);
 624
 625     return response();
 626 }
 627
 628 QString WebApplication::clientId() const
 629 {
 630     return m_clientAddress.toString();
 631 }
 632
 633 void WebApplication::sessionInitialize()
 634 {
 635     Q_ASSERT(!m_currentSession);
 636
 637     const QString sessionId {parseCookie(m_request.headers.value(u"cookie"_s)).value(m_sessionCookieName)};
 638
 639     // TODO: Additional session check
 640
 641     if (!sessionId.isEmpty())
 642     {
 643         m_currentSession = m_sessions.value(sessionId);
 644         if (m_currentSession)
 645         {
 646             if (m_currentSession->hasExpired(m_sessionTimeout))
 647             {
 648                 // session is outdated - removing it
 649                 delete m_sessions.take(sessionId);
 650                 m_currentSession = nullptr;
 651             }
 652             else
 653             {
 654                 m_currentSession->updateTimestamp();
 655             }
 656         }
 657         else
 658         {
 659             qDebug() << Q_FUNC_INFO << "session does not exist!";
 660         }
 661     }
 662
 663     if (!m_currentSession && !isAuthNeeded())
 664         sessionStart();
 665 }
 666
 667 QString WebApplication::generateSid() const
 668 {
 669     QString sid;
 670
 671     do
 672     {
 673         const quint32 tmp[] =
 674         {Utils::Random::rand(), Utils::Random::rand(), Utils::Random::rand()
 675                 , Utils::Random::rand(), Utils::Random::rand(), Utils::Random::rand()};
 676         sid = QString::fromLatin1(QByteArray::fromRawData(reinterpret_cast<const char *>(tmp), sizeof(tmp)).toBase64());
 677     }
 678     while (m_sessions.contains(sid));
 679
 680     return sid;
 681 }
 682
 683 bool WebApplication::isAuthNeeded()
 684 {
 685     if (!m_isLocalAuthEnabled && Utils::Net::isLoopbackAddress(m_clientAddress))
 686         return false;
 687     if (m_isAuthSubnetWhitelistEnabled && Utils::Net::isIPInSubnets(m_clientAddress, m_authSubnetWhitelist))
 688         return false;
 689     return true;
 690 }
 691
 692 bool WebApplication::isPublicAPI(const QString &scope, const QString &action) const
 693 {
 694     return m_publicAPIs.contains(u"%1/%2"_s.arg(scope, action));
 695 }
 696
 697 void WebApplication::sessionStart()
 698 {
 699     Q_ASSERT(!m_currentSession);
 700
 701     // remove outdated sessions
 702     Algorithm::removeIf(m_sessions, [this](const QString &, const WebSession *session)
 703     {
 704         if (session->hasExpired(m_sessionTimeout))
 705         {
 706             delete session;
 707             return true;
 708         }
 709
 710         return false;
 711     });
 712
 713     m_currentSession = new WebSession(generateSid(), app());
 714     m_sessions[m_currentSession->id()] = m_currentSession;
 715
 716     m_currentSession->registerAPIController<AppController>(u"app"_s);
 717     m_currentSession->registerAPIController<LogController>(u"log"_s);
 718     m_currentSession->registerAPIController<RSSController>(u"rss"_s);
 719     m_currentSession->registerAPIController<SearchController>(u"search"_s);
 720     m_currentSession->registerAPIController<TorrentsController>(u"torrents"_s);
 721     m_currentSession->registerAPIController<TransferController>(u"transfer"_s);
 722
 723     auto *syncController = m_currentSession->registerAPIController<SyncController>(u"sync"_s);
 724     syncController->updateFreeDiskSpace(m_freeDiskSpaceChecker->lastResult());
 725     connect(m_freeDiskSpaceChecker, &FreeDiskSpaceChecker::checked, syncController, &SyncController::updateFreeDiskSpace);
 726
 727     QNetworkCookie cookie {m_sessionCookieName.toLatin1(), m_currentSession->id().toUtf8()};
 728     cookie.setHttpOnly(true);
 729     cookie.setSecure(m_isSecureCookieEnabled && m_isHttpsEnabled);
 730     cookie.setPath(u"/"_s);
 731     QByteArray cookieRawForm = cookie.toRawForm();
 732     if (m_isCSRFProtectionEnabled)
 733         cookieRawForm.append("; SameSite=Strict");
 734     else if (cookie.isSecure())
 735         cookieRawForm.append("; SameSite=None");
 736     setHeader({Http::HEADER_SET_COOKIE, QString::fromLatin1(cookieRawForm)});
 737 }
 738
 739 void WebApplication::sessionEnd()
 740 {
 741     Q_ASSERT(m_currentSession);
 742
 743     QNetworkCookie cookie {m_sessionCookieName.toLatin1()};
 744     cookie.setPath(u"/"_s);
 745     cookie.setExpirationDate(QDateTime::currentDateTime().addDays(-1));
 746
 747     delete m_sessions.take(m_currentSession->id());
 748     m_currentSession = nullptr;
 749
 750     setHeader({Http::HEADER_SET_COOKIE, QString::fromLatin1(cookie.toRawForm())});
 751 }
 752
 753 bool WebApplication::isCrossSiteRequest(const Http::Request &request) const
 754 {
 755     // https://www.owasp.org/index.php/Cross-Site_Request_Forgery_(CSRF)_Prevention_Cheat_Sheet#Verifying_Same_Origin_with_Standard_Headers
 756
 757     const auto isSameOrigin = [](const QUrl &left, const QUrl &right) -> bool
 758     {
 759         // [rfc6454] 5. Comparing Origins
 760         return ((left.port() == right.port())
 761                 // && (left.scheme() == right.scheme())  // not present in this context
 762                 && (left.host() == right.host()));
 763     };
 764
 765     const QString targetOrigin = request.headers.value(Http::HEADER_X_FORWARDED_HOST, request.headers.value(Http::HEADER_HOST));
 766     const QString originValue = request.headers.value(Http::HEADER_ORIGIN);
 767     const QString refererValue = request.headers.value(Http::HEADER_REFERER);
 768
 769     if (originValue.isEmpty() && refererValue.isEmpty())
 770     {
 771         // owasp.org recommends to block this request, but doing so will inevitably lead Web API users to spoof headers
 772         // so lets be permissive here
 773         return false;
 774     }
 775
 776     // sent with CORS requests, as well as with POST requests
 777     if (!originValue.isEmpty())
 778     {
 779         const bool isInvalid = !isSameOrigin(urlFromHostHeader(targetOrigin), originValue);
 780         if (isInvalid)
 781         {
 782             LogMsg(tr("WebUI: Origin header & Target origin mismatch! Source IP: '%1'. Origin header: '%2'. Target origin: '%3'")
 783                    .arg(m_env.clientAddress.toString(), originValue, targetOrigin)
 784                    , Log::WARNING);
 785         }
 786         return isInvalid;
 787     }
 788
 789     if (!refererValue.isEmpty())
 790     {
 791         const bool isInvalid = !isSameOrigin(urlFromHostHeader(targetOrigin), refererValue);
 792         if (isInvalid)
 793         {
 794             LogMsg(tr("WebUI: Referer header & Target origin mismatch! Source IP: '%1'. Referer header: '%2'. Target origin: '%3'")
 795                    .arg(m_env.clientAddress.toString(), refererValue, targetOrigin)
 796                    , Log::WARNING);
 797         }
 798         return isInvalid;
 799     }
 800
 801     return true;
 802 }
 803
 804 bool WebApplication::validateHostHeader(const QStringList &domains) const
 805 {
 806     const QUrl hostHeader = urlFromHostHeader(m_request.headers[Http::HEADER_HOST]);
 807     const QString requestHost = hostHeader.host();
 808
 809     // (if present) try matching host header's port with local port
 810     const int requestPort = hostHeader.port();
 811     if ((requestPort != -1) && (m_env.localPort != requestPort))
 812     {
 813         LogMsg(tr("WebUI: Invalid Host header, port mismatch. Request source IP: '%1'. Server port: '%2'. Received Host header: '%3'")
 814                .arg(m_env.clientAddress.toString()).arg(m_env.localPort)
 815                .arg(m_request.headers[Http::HEADER_HOST])
 816                 , Log::WARNING);
 817         return false;
 818     }
 819
 820     // try matching host header with local address
 821     const bool sameAddr = m_env.localAddress.isEqual(QHostAddress(requestHost));
 822
 823     if (sameAddr)
 824         return true;
 825
 826     // try matching host header with domain list
 827     for (const auto &domain : domains)
 828     {
 829         const QRegularExpression domainRegex {Utils::String::wildcardToRegexPattern(domain), QRegularExpression::CaseInsensitiveOption};
 830         if (requestHost.contains(domainRegex))
 831             return true;
 832     }
 833
 834     LogMsg(tr("WebUI: Invalid Host header. Request source IP: '%1'. Received Host header: '%2'")
 835            .arg(m_env.clientAddress.toString(), m_request.headers[Http::HEADER_HOST])
 836             , Log::WARNING);
 837     return false;
 838 }
 839
 840 QHostAddress WebApplication::resolveClientAddress() const
 841 {
 842     if (!m_isReverseProxySupportEnabled)
 843         return m_env.clientAddress;
 844
 845     // Only reverse proxy can overwrite client address
 846     if (!Utils::Net::isIPInSubnets(m_env.clientAddress, m_trustedReverseProxyList))
 847         return m_env.clientAddress;
 848
 849     const QString forwardedFor = m_request.headers.value(Http::HEADER_X_FORWARDED_FOR);
 850
 851     if (!forwardedFor.isEmpty())
 852     {
 853         // client address is the 1st global IP in X-Forwarded-For or, if none available, the 1st IP in the list
 854         const QStringList remoteIpList = forwardedFor.split(u',', Qt::SkipEmptyParts);
 855
 856         if (!remoteIpList.isEmpty())
 857         {
 858             QHostAddress clientAddress;
 859
 860             for (const QString &remoteIp : remoteIpList)
 861             {
 862                 if (clientAddress.setAddress(remoteIp) && clientAddress.isGlobal())
 863                     return clientAddress;
 864             }
 865
 866             if (clientAddress.setAddress(remoteIpList[0]))
 867                 return clientAddress;
 868         }
 869     }
 870
 871     return m_env.clientAddress;
 872 }
 873
 874 // WebSession
 875
 876 WebSession::WebSession(const QString &sid, IApplication *app)
 877     : ApplicationComponent(app)
 878     , m_sid {sid}
 879 {
 880     updateTimestamp();
 881 }
 882
 883 QString WebSession::id() const
 884 {
 885     return m_sid;
 886 }
 887
 888 bool WebSession::hasExpired(const qint64 seconds) const
 889 {
 890     if (seconds <= 0)
 891         return false;
 892     return m_timer.hasExpired(seconds * 1000);
 893 }
 894
 895 void WebSession::updateTimestamp()
 896 {
 897     m_timer.start();
 898 }
 899
 900 APIController *WebSession::getAPIController(const QString &scope) const
 901 {
 902     return m_apiControllers.value(scope);
 903 }