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// Copyright (C) 2016 Kurt Pattyn <pattyn.kurt@gmail.com>.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
// Qt-Security score:critical reason:network-protocol
#include "qwebsockethandshakeresponse_p.h"
#include "qwebsockethandshakerequest_p.h"
#include "qwebsocketprotocol.h"
#include "qwebsocketprotocol_p.h"
#include <QtCore/QString>
#include <QtCore/QTextStream>
#include <QtCore/QByteArray>
#include <QtCore/QStringList>
#include <QtCore/QDateTime>
#include <QtCore/QLocale>
#include <QtCore/QCryptographicHash>
#include <QtCore/QSet>
#include <QtCore/QList>
#include <QtCore/QStringBuilder> //for more efficient string concatenation
#include <algorithm>
#include <functional> //for std::greater
#include <iterator>
QT_BEGIN_NAMESPACE
/*!
\internal
*/
QWebSocketHandshakeResponse::QWebSocketHandshakeResponse(
const QWebSocketHandshakeRequest &request,
const QString &serverName,
bool isOriginAllowed,
const QList<QWebSocketProtocol::Version> &supportedVersions,
const QList<QString> &supportedProtocols,
const QList<QString> &supportedExtensions) :
m_isValid(false),
m_canUpgrade(false),
m_response(),
m_acceptedProtocol(),
m_acceptedExtension(),
m_acceptedVersion(QWebSocketProtocol::VersionUnknown),
m_error(QWebSocketProtocol::CloseCodeNormal),
m_errorString()
{
m_response = getHandshakeResponse(request, serverName,
isOriginAllowed, supportedVersions,
supportedProtocols, supportedExtensions);
m_isValid = true;
}
/*!
\internal
*/
QWebSocketHandshakeResponse::~QWebSocketHandshakeResponse()
{
}
/*!
\internal
*/
bool QWebSocketHandshakeResponse::isValid() const
{
return m_isValid;
}
/*!
\internal
*/
bool QWebSocketHandshakeResponse::canUpgrade() const
{
return m_isValid && m_canUpgrade;
}
/*!
\internal
*/
QString QWebSocketHandshakeResponse::acceptedProtocol() const
{
return m_acceptedProtocol;
}
/*!
\internal
*/
QString QWebSocketHandshakeResponse::calculateAcceptKey(const QString &key) const
{
//the UID comes from RFC6455
const QString tmpKey = key % QStringLiteral("258EAFA5-E914-47DA-95CA-C5AB0DC85B11");
const QByteArray hash = QCryptographicHash::hash(tmpKey.toLatin1(), QCryptographicHash::Sha1);
return QString::fromLatin1(hash.toBase64());
}
template <class T, class Compare>
static QList<T> listIntersection(QList<T> list1, QList<T> list2, Compare comp)
{
QList<T> result;
std::sort(list1.begin(), list1.end(), comp);
std::sort(list2.begin(), list2.end(), comp);
std::set_intersection(list1.cbegin(), list1.cend(),
list2.cbegin(), list2.cend(),
std::back_inserter(result), comp);
return result;
}
/*!
\internal
*/
QString QWebSocketHandshakeResponse::getHandshakeResponse(
const QWebSocketHandshakeRequest &request,
const QString &serverName,
bool isOriginAllowed,
const QList<QWebSocketProtocol::Version> &supportedVersions,
const QList<QString> &supportedProtocols,
const QList<QString> &supportedExtensions)
{
QStringList response;
m_canUpgrade = false;
if (!isOriginAllowed) {
if (!m_canUpgrade) {
m_error = QWebSocketProtocol::CloseCodePolicyViolated;
m_errorString = tr("Access forbidden.");
response << QStringLiteral("HTTP/1.1 403 Access Forbidden");
}
} else {
if (request.isValid()) {
const QString acceptKey = calculateAcceptKey(request.key());
// Find first client protocol that is supported. Order is important!
const QString protocol = [&] {
const auto clientProtocols = request.protocols();
const auto isSupportedProtocol = [&](const QString &protocol) {
return supportedProtocols.contains(protocol);
};
const auto it = std::find_if(
clientProtocols.constBegin(), clientProtocols.constEnd(),
isSupportedProtocol);
return it == clientProtocols.constEnd() ? QString() : *it;
}();
//TODO: extensions must be kept in the order in which they arrive
//cannot use set.intersect() to get the supported extensions
const QList<QString> matchingExtensions =
listIntersection(supportedExtensions, request.extensions(),
std::less<QString>());
const QList<QWebSocketProtocol::Version> matchingVersions =
listIntersection(supportedVersions, request.versions(),
std::greater<QWebSocketProtocol::Version>()); //sort in descending order
if (Q_UNLIKELY(matchingVersions.isEmpty())) {
m_error = QWebSocketProtocol::CloseCodeProtocolError;
m_errorString = tr("Unsupported version requested.");
m_canUpgrade = false;
} else {
response << QStringLiteral("HTTP/1.1 101 Switching Protocols") <<
QStringLiteral("Upgrade: websocket") <<
QStringLiteral("Connection: Upgrade") <<
QStringLiteral("Sec-WebSocket-Accept: ") % acceptKey;
if (!protocol.isEmpty()) {
m_acceptedProtocol = protocol;
response << QStringLiteral("Sec-WebSocket-Protocol: ") % m_acceptedProtocol;
}
if (!matchingExtensions.isEmpty()) {
m_acceptedExtension = matchingExtensions.first();
response << QStringLiteral("Sec-WebSocket-Extensions: ") % m_acceptedExtension;
}
QString origin = request.origin().trimmed();
if (origin.contains(QStringLiteral("\r\n")) ||
serverName.contains(QStringLiteral("\r\n"))) {
m_error = QWebSocketProtocol::CloseCodeAbnormalDisconnection;
m_errorString = tr("One of the headers contains a newline. " \
"Possible attack detected.");
m_canUpgrade = false;
} else {
if (origin.isEmpty())
origin = QStringLiteral("*");
QDateTime datetime = QDateTime::currentDateTimeUtc();
if (!serverName.isEmpty())
response << QStringLiteral("Server: ") % serverName;
response << QStringLiteral("Access-Control-Allow-Credentials: false") <<
QStringLiteral("Access-Control-Allow-Methods: GET") <<
QStringLiteral("Access-Control-Allow-Headers: content-type") <<
QStringLiteral("Access-Control-Allow-Origin: ") % origin <<
QStringLiteral("Date: ") % QLocale::c()
.toString(datetime, QStringLiteral("ddd, dd MMM yyyy hh:mm:ss 'GMT'"));
m_acceptedVersion = QWebSocketProtocol::currentVersion();
m_canUpgrade = true;
}
}
} else {
m_error = QWebSocketProtocol::CloseCodeProtocolError;
m_errorString = tr("Bad handshake request received.");
m_canUpgrade = false;
}
if (Q_UNLIKELY(!m_canUpgrade)) {
response << QStringLiteral("HTTP/1.1 400 Bad Request");
QStringList versions;
for (QWebSocketProtocol::Version version : supportedVersions)
versions << QString::number(static_cast<int>(version));
response << QStringLiteral("Sec-WebSocket-Version: ")
% versions.join(QStringLiteral(", "));
}
}
response << QStringLiteral("\r\n"); //append empty line at end of header
return response.join(QStringLiteral("\r\n"));
}
/*!
\internal
*/
QTextStream &QWebSocketHandshakeResponse::writeToStream(QTextStream &textStream) const
{
if (Q_LIKELY(!m_response.isEmpty()))
textStream << m_response.toLatin1().constData();
else
textStream.setStatus(QTextStream::WriteFailed);
return textStream;
}
/*!
\internal
*/
QTextStream &operator <<(QTextStream &stream, const QWebSocketHandshakeResponse &response)
{
return response.writeToStream(stream);
}
/*!
\internal
*/
QWebSocketProtocol::Version QWebSocketHandshakeResponse::acceptedVersion() const
{
return m_acceptedVersion;
}
/*!
\internal
*/
QWebSocketProtocol::CloseCode QWebSocketHandshakeResponse::error() const
{
return m_error;
}
/*!
\internal
*/
QString QWebSocketHandshakeResponse::errorString() const
{
return m_errorString;
}
/*!
\internal
*/
QString QWebSocketHandshakeResponse::acceptedExtension() const
{
return m_acceptedExtension;
}
QT_END_NAMESPACE